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Lu J, Huang S, Wei S, Cheng J, Li W, Fei Y, Yang J, Hu R, Huang S, Zhai W, Wu Z, Liu M, Xu Q, Hu P, Chen L. Heat inducible nuclear translocation of Kdm6bb drives temperature dependent sex reversal in Nile tilapia. PLoS Genet 2025; 21:e1011664. [PMID: 40305565 PMCID: PMC12043187 DOI: 10.1371/journal.pgen.1011664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2024] [Accepted: 03/24/2025] [Indexed: 05/02/2025] Open
Abstract
Understanding the primary molecular events driving temperature-dependent sex reversal (TSR) has proven challenging, particularly in distinguishing these from secondary effects of sexual differentiation. The mechanisms translating temperature into a sex-determining signal in fish are still largely unknown. Through combined transcriptomic and genome-wide histone methylation analyses of gonads in Nile tilapia (Oreochromis niloticus) exposed to normal and elevated temperatures, we observed significant upregulation of male-promoting genes (amh, dmrt1, gsdf) and suppression of female-promoting genes (wt1a and foxl3) at high temperature. These changes were correlated with methylation changes in H3K27 and H3K4 in the promoter regions of these genes. Among the histone methylation enzymes induced by high temperature, we identified the H3K27 demethylase Kdm6bb to be a key factor. Gene deletion and biochemical studies confirmed that Kdm6bb significantly impacts the H3K27 methylation level, that influences sex determination. Crucially, we discovered that the TSR function of Kdm6bb is mediated by the alternative inclusion of a previously unrecognized intron, enabling nuclear translocation of the demethylase to perform its function. Our findings refute the previously proposed "translation deficiency" mechanism of kdm6bb, and highlight the critical role of mRNA alternative splicing and subcellular localization of the demethylase in temperature-induced sex reversal.
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Affiliation(s)
- Jigang Lu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Siqi Huang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Shicen Wei
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Jiangbo Cheng
- The State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, Gansu, China
| | - Wei Li
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Yueyue Fei
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Jihui Yang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Ruiqin Hu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Songqian Huang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Wanying Zhai
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Zhichao Wu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Mingli Liu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Qianghua Xu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Peng Hu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Liangbiao Chen
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
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2
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Branciamore S, Rodin AS, Riggs AD. Stochastic Epigenetic Modification and Evolution of Sex Determination in Vertebrates. J Mol Evol 2024; 92:861-873. [PMID: 39565411 PMCID: PMC11646274 DOI: 10.1007/s00239-024-10213-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 10/19/2024] [Indexed: 11/21/2024]
Abstract
In this report, we propose a novel mathematical model of the origin and evolution of sex determination in vertebrates that is based on the stochastic epigenetic modification (SEM) mechanism. We have previously shown that SEM, with rates consistent with experimental observation, can both increase the rate of gene fixation and decrease pseudogenization, thus dramatically improving the efficacy of evolution. Here, we present a conjectural model of the origin and evolution of sex determination wherein the SEM mechanism alone is sufficient to parsimoniously trigger and guide the evolution of heteromorphic sex chromosomes from the initial homomorphic chromosome configuration, without presupposing any allele frequency differences. Under this theoretical model, the SEM mechanism (i) predated vertebrate sex determination origins and evolution, (ii) has been conveniently and parsimoniously co-opted by the vertebrate sex determination systems during the evolutionary transitioning to the extant vertebrate sex determination, likely acting "on top" of these systems, and (iii) continues existing, alongside all known vertebrate sex determination systems, as a universal pan-vertebrate sex determination modulation mechanism.
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Affiliation(s)
- Sergio Branciamore
- Department of Computational and Quantitative Medicine, Beckman Research Institute of City of Hope, Duarte, USA.
| | - Andrei S Rodin
- Department of Computational and Quantitative Medicine, Beckman Research Institute of City of Hope, Duarte, USA.
| | - Arthur D Riggs
- Diabetes and Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte , USA
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3
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Tovar-Bohórquez O, McKenzie D, Crestel D, Vandeputte M, Geffroy B. Thermal modulation of energy allocation during sex determination in the European sea bass (Dicentrarchus labrax). Gene 2024; 927:148721. [PMID: 38925525 DOI: 10.1016/j.gene.2024.148721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 06/17/2024] [Accepted: 06/20/2024] [Indexed: 06/28/2024]
Abstract
Water temperature governs physiological functions such as growth, energy allocation, and sex determination in ectothermic species. The European sea bass (Dicentrarchus labrax) is a major species in European aquaculture, exhibiting early dimorphic growth favoring females. The species has a polygenic sex determination system that interacts with water temperature to determine an individual's sex, with two periods during development that are sensitive to temperature. The current study investigated the influence of water temperature on energy allocation and sex-biased genes during sex determination and differentiation periods. RNA-Sequencing and qPCR analyses were conducted in two separate experiments, of either constant water temperatures typical of aquaculture conditions or natural seasonal thermal regimes, respectively. We focused on eight key genes associated with energy allocation, growth regulation, and sex determination and differentiation. In Experiment 1, cold and warm temperature treatments favored female and male proportions, respectively. The RNA-seq analysis highlighted sex-dependent energy allocation transcripts, with higher levels of nucb1 and pomc1 in future females, and increased levels of egfra and spry1 in future males. In Experiment 2, a warm thermal regime favored females, while a cold regime favored males. qPCR analysis in Experiment 2 revealed that ghrelin and nucb1 were down-regulated by warm temperatures. A significant sex-temperature interaction was observed for pank1a with higher and lower expression for males in the cold and warm regimes respectively, compared to females. Notably, spry1 displayed increased expression in future males at the all-fins stage and in males undergoing molecular sex differentiation in both experimental conditions, indicating that it provides a novel, robust, and consistent marker for masculinization. Overall, our findings emphasize the complex interplay of genes involved in feeding, energy allocation, growth, and sex determination in response to temperature variations in the European sea bass.
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Affiliation(s)
| | - David McKenzie
- MARBEC, Ifremer, IRD, Univ Montpellier, CNRS, Palavas-Les-Flots, France
| | - Damien Crestel
- MARBEC, Ifremer, IRD, Univ Montpellier, CNRS, Palavas-Les-Flots, France
| | - Marc Vandeputte
- MARBEC, Ifremer, IRD, Univ Montpellier, CNRS, Palavas-Les-Flots, France; Université Paris-Saclay, INRAE, AgroParisTech, GABI, Jouy-en-Josas, France
| | - Benjamin Geffroy
- MARBEC, Ifremer, IRD, Univ Montpellier, CNRS, Palavas-Les-Flots, France.
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Martínez-Pacheco M, Díaz-Barba K, Pérez-Molina R, Marmolejo-Valencia A, Collazo-Saldaña P, Escobar-Rodríguez M, Sánchez-Pérez M, Meneses-Acosta A, Martínez-Rizo AB, Sánchez-Pacheco AU, Furlan-Magaril M, Merchant-Larios H, Cortez D. Gene expression dynamics during temperature-dependent sex determination in a sea turtle. Dev Biol 2024; 514:99-108. [PMID: 38914191 DOI: 10.1016/j.ydbio.2024.06.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 06/26/2024]
Abstract
Fifty years ago, researchers discovered a link between ambient temperature and the sex of turtle embryos. More recently, significant progress has been made in understanding the influence of temperature on freshwater turtles. However, our understanding of the key genetic factors in other turtle groups, such as sea turtles, remains limited. To address this gap, we conducted RNA-seq analyses on embryonic tissues from the sea olive ridley turtle during the thermosensitive period (stages 21-26) at temperatures known to produce males (26 °C) and females (33 °C). Our findings revealed that incubation temperatures primarily influence genes with broad expression across tissues due to differential cell division rates and later have an effect regulating gonad-specific transcripts. This effect is mostly related to gene activation rather than transcription repression. We performed transcriptome analyses following shifts in incubation temperatures of bi-potential gonads. This approach allowed us to identify genes that respond rapidly and may be closer to the beginning of the temperature-sensing pathway. Notably, we observed swift adaptations in the expression levels of chromatin modifiers JARID2 and KDM6B, as well as the splicing factor SRSF5, and transcription regulators THOC2, DDX3X and CBX3, but little impact in the overall gonad-specific pathways, indicating that temperature-sensing genes may change rapidly but the rewiring of the gonad's developmental fate is complex and resilient. AUTHOR SUMMARY: Sea turtles, one of the most iconic creatures of our oceans, confront a troubling reality of endangerment, a peril magnified by the looming specter of climate change. This climatic shift is gradually increasing the temperature of the nesting beaches thus causing dramatic male/female population biases. Conservation efforts will need genetic and molecular information to reverse the negative effects of climate change on the populations. In this study, we conducted the first transcriptomic analysis of embryonic tissues, including gonads, brain, liver, and mesonephros, in the olive ridley sea turtle during the critical thermosensitive period spanning stages 21-26. We examined both male-producing (26 °C) and female-producing (33 °C) temperatures and found that incubation temperatures influence temperature-sensitive genes that are either expressed globally or specifically associated with the gonads. These findings indicate that incubation temperatures predominantly sway genes with broad expression patterns due to differential cell division rates. This natural process was opted in the gonads to drive sex determination. We also identified genes that are rapidly capable of sensing temperature changes and that could play a role in the activation of the sex determination pathway. Overall, our study sheds light on the intricate interplay between temperature and gene expression during sea turtle development, revealing dynamic changes in the transcriptome and highlighting the involvement of key genetic players in sex determination.
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Affiliation(s)
| | | | - Rosario Pérez-Molina
- Departamento de Genética Molecular, Instituto de Fisiología Celular, UNAM, Mexico City, Mexico.
| | - Alejandro Marmolejo-Valencia
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, UNAM, Mexico City, Mexico.
| | - Pedro Collazo-Saldaña
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, UNAM, Mexico City, Mexico.
| | | | | | | | | | | | - Mayra Furlan-Magaril
- Departamento de Genética Molecular, Instituto de Fisiología Celular, UNAM, Mexico City, Mexico.
| | - Horacio Merchant-Larios
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, UNAM, Mexico City, Mexico.
| | - Diego Cortez
- Centro de Ciencias Genómicas, UNAM, CP62210, Cuernavaca, Mexico.
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Chen Q, Sun W, Jin L, Zhou Y, Li F, Ge C. Overexpression of Kdm6b induces testicular differentiation in a temperature-dependent sex determination system. Zool Res 2024; 45:1108-1115. [PMID: 39245653 PMCID: PMC11491778 DOI: 10.24272/j.issn.2095-8137.2024.186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2024] [Accepted: 08/12/2024] [Indexed: 09/10/2024] Open
Abstract
In reptiles, such as the red-eared slider turtle ( Trachemys scripta elegans), gonadal sex determination is highly dependent on the environmental temperature during embryonic stages. This complex process, which leads to differentiation into either testes or ovaries, is governed by the finely tuned expression of upstream genes, notably the testis-promoting gene Dmrt1 and the ovary-promoting gene Foxl2. Recent studies have identified epigenetic regulation as a crucial factor in testis development, with the H3K27me3 demethylase KDM6B being essential for Dmrt1 expression in T. s. elegans. However, whether KDM6B alone can induce testicular differentiation remains unclear. In this study, we found that overexpression of Kdm6b in T. s. elegans embryos induced the male development pathway, accompanied by a rapid increase in the gonadal expression of Dmrt1 at 31°C, a temperature typically resulting in female development. Notably, this sex reversal could be entirely rescued by Dmrt1 knockdown. These findings demonstrate that Kdm6b is sufficient for commitment to the male pathway, underscoring its role as a critical epigenetic regulator in the sex determination of the red-eared slider turtle.
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Affiliation(s)
- Qiran Chen
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China
- Institute of Animal Sex and Development, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China
| | - Wei Sun
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China
- Institute of Animal Sex and Development, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China
| | - Lin Jin
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China
- Institute of Animal Sex and Development, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China
| | - Yingjie Zhou
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China
- Institute of Animal Sex and Development, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China
| | - Fang Li
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China
- Institute of Animal Sex and Development, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China
| | - Chutian Ge
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China
- Institute of Animal Sex and Development, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China. E-mail:
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6
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Haltenhof T, Preußner M, Heyd F. Thermoregulated transcriptomics: the molecular basis and biological significance of temperature-dependent alternative splicing. Biochem J 2024; 481:999-1013. [PMID: 39083035 PMCID: PMC11346455 DOI: 10.1042/bcj20230410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 07/05/2024] [Accepted: 07/16/2024] [Indexed: 08/28/2024]
Abstract
Temperature-dependent alternative splicing (AS) is a crucial mechanism for organisms to adapt to varying environmental temperatures. In mammals, even slight fluctuations in body temperature are sufficient to drive significant AS changes in a concerted manner. This dynamic regulation allows organisms to finely tune gene expression and protein isoform diversity in response to temperature cues, ensuring proper cellular function and physiological adaptation. Understanding the molecular mechanisms underlying temperature-dependent AS thus provides valuable insights into the intricate interplay between environmental stimuli and gene expression regulation. In this review, we provide an overview of recent advances in understanding temperature-regulated AS across various biological processes and systems. We will discuss the machinery sensing and translating temperature cues into changed AS patterns, the adaptation of the splicing regulatory machinery to extreme temperatures, the role of temperature-dependent AS in shaping the transcriptome, functional implications and the development of potential therapeutics targeting temperature-sensitive AS pathways.
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Affiliation(s)
- Tom Haltenhof
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Takustrasse 6, 14195 Berlin, Germany
| | - Marco Preußner
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Takustrasse 6, 14195 Berlin, Germany
| | - Florian Heyd
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Takustrasse 6, 14195 Berlin, Germany
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7
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Straková B, Kubička L, Červenka J, Kratochvíl L. Pivotal temperature is not for everyone: Evidence for temperature-dependent sex determination in three gecko species. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024; 341:597-605. [PMID: 38497303 DOI: 10.1002/jez.2808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/19/2024]
Abstract
The prevalence of environmental sex determination (ESD) in squamate reptiles is often overestimated in the literature. This is surprising because we have reliable data demonstrating ESD in only a few species. The documentation of ESD in three species of geckos presented here has significantly increased our knowledge, given that satisfactory evidence for ESD existed in only eight other gecko species. For the first time, we document the occurrence of ESD in the family Sphaerodactylidae. Our finding of unexpected variability in the shapes of reaction norms among geckos highlights that traditional descriptions using parameters such as pivotal temperature, that is, temperature producing a 50:50 sex ratio, are unsatisfactory. For example, the gecko Pachydactylus tigrinus lacks any pivotal temperature and its sex ratios are strongly female-biased across the entire range of viable temperatures. We argue for the effective capture of the relationship between temperature and sex ratio using specific nonlinear models rather than using classical simplistic descriptions and classifications of reaction norms.
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Affiliation(s)
- Barbora Straková
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Lukáš Kubička
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jan Červenka
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
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8
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Uno Y, Matsubara K. Unleashing diversity through flexibility: The evolutionary journey of sex chromosomes in amphibians and reptiles. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024; 341:230-241. [PMID: 38155517 DOI: 10.1002/jez.2776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 12/01/2023] [Accepted: 12/05/2023] [Indexed: 12/30/2023]
Abstract
Sex determination systems have greatly diversified between amphibians and reptiles, with such as the different sex chromosome compositions within a single species and transition between temperature-dependent sex determination (TSD) and genetic sex determination (GSD). In most sex chromosome studies on amphibians and reptiles, the whole-genome sequence of Xenopous tropicalis and chicken have been used as references to compare the chromosome homology of sex chromosomes among each of these taxonomic groups, respectively. In the present study, we reviewed existing reports on sex chromosomes, including karyotypes, in amphibians and reptiles. Furthermore, we compared the identified genetic linkages of sex chromosomes in amphibians and reptiles with the chicken genome as a reference, which is believed to resemble the ancestral tetrapod karyotype. Our findings revealed that sex chromosomes in amphibians are derived from genetic linkages homologous to various chicken chromosomes, even among several frogs within single families, such as Ranidae and Pipidae. In contrast, sex chromosomes in reptiles exhibit conserved genetic linkages with chicken chromosomes, not only across most species within a single family, but also within closely related families. The diversity of sex chromosomes in amphibians and reptiles may be attributed to the flexibility of their sex determination systems, including the ease of sex reversal in these animals.
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Affiliation(s)
- Yoshinobu Uno
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Kazumi Matsubara
- Department of Bioscience and Biotechnology, Graduate School of Bioscience and Biotechnology, Chubu University, Kasugai, Aichi, Japan
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9
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Li M, Sun L, Zhou L, Wang D. Tilapia, a good model for studying reproductive endocrinology. Gen Comp Endocrinol 2024; 345:114395. [PMID: 37879418 DOI: 10.1016/j.ygcen.2023.114395] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 10/07/2023] [Accepted: 10/21/2023] [Indexed: 10/27/2023]
Abstract
The Nile tilapia (Oreochromis niloticus), with a system of XX/XY sex determination, is a worldwide farmed fish with a shorter sexual maturation time than that of most cultured fish. Tilapia show a spawning cycle of approximately 14 days and can be artificially propagated in the laboratory all year round to obtain genetically all female (XX) and all male (XY) fry. Its genome sequence has been opened, and a perfect gene editing platform has been established. With a moderate body size, it is convenient for taking enough blood to measure hormone level. In recent years, using tilapia as animal model, we have confirmed that estrogen is crucial for female development because 1) mutation of star2, cyp17a1 or cyp19a1a (encoding aromatase, the key enzyme for estrogen synthesis) results in sex reversal (SR) due to estrogen deficiency in XX tilapia, while mutation of star1, cyp11a1, cyp17a2, cyp19a1b or cyp11c1 affects fertility due to abnormal androgen, cortisol and DHP levels in XY tilapia; 2) when the estrogen receptors (esr2a/esr2b) are mutated, the sex is reversed from female to male, while when the androgen receptors are mutated, the sex cannot be reversed; 3) the differentiated ovary can be transdifferentiated into functional testis by inhibition of estrogen synthesis, and the differentiated testis can be transdifferentiated into ovary by simultaneous addition of exogenous estrogen and androgen synthase inhibitor; 4) loss of male pathway genes amhy, dmrt1, gsdf causes SR with upregulation of cyp19a1a in XY tilapia. Disruption of estrogen synthesis rescues the male to female SR of amhy and gsdf but not dmrt1 mutants; 5) mutation of female pathway genes foxl2 and sf-1 causes SR with downregulation of cyp19a1a in XX tilapia; 6) the germ cell SR of foxl3 mutants fails to be rescued by estrogen treatment, indicating that estrogen determines female germ cell fate through foxl3. This review also summarized the effects of deficiency of other steroid hormones, such as androgen, DHP and cortisol, on fish reproduction. Overall, these studies demonstrate that tilapia is an excellent animal model for studying reproductive endocrinology of fish.
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Affiliation(s)
- Minghui Li
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Lina Sun
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Linyan Zhou
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China
| | - Deshou Wang
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China.
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10
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Akashi H, Hasui D, Ueda K, Ishikawa M, Takeda M, Miyagawa S. Understanding the role of environmental temperature on sex determination through comparative studies in reptiles and amphibians. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024; 341:48-59. [PMID: 37905472 DOI: 10.1002/jez.2760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 09/26/2023] [Accepted: 09/28/2023] [Indexed: 11/02/2023]
Abstract
In vertebrates, species exhibit phenotypic plasticity of sex determination that the sex can plastically be determined by the external environmental temperature through a mechanism, temperature-dependent sex determination (TSD). Temperature exerts influence over the direction of sexual differentiation pathways, resulting in distinct primary sex ratios in a temperature-dependent manner. This review provides a summary of the thermal sensitivities associated with sex determination in reptiles and amphibians, with a focus on the pattern of TSD, gonadal differentiation, temperature sensing, and the molecular basis underlying thermal sensitivity in sex determination. Comparative studies across diverse lineages offer valuable insights into comprehending the evolution of sex determination as a phenotypic plasticity. While evidence of molecular mechanisms governing sexual differentiation pathways continues to accumulate, the intracellular signaling linking temperature sensing and sexual differentiation pathways remains elusive. We emphasize that uncovering these links is a key for understanding species-specific thermal sensitivities in TSD and will contribute to a more comprehensive understanding of ecosystem and biodiversity conservations.
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Affiliation(s)
- Hiroshi Akashi
- Department of Integrated Biosciences, The University of Tokyo, Chiba, Japan
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, Tokyo, Japan
| | - Daiki Hasui
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, Tokyo, Japan
| | - Kai Ueda
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, Tokyo, Japan
| | - Momoka Ishikawa
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, Tokyo, Japan
| | | | - Shinichi Miyagawa
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, Tokyo, Japan
- Research Institute for Science and Technology, Tokyo University of Science, Tokyo, Japan
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11
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Toyota K, Akashi H, Ishikawa M, Yamaguchi K, Shigenobu S, Sato T, Lange A, Tyler CR, Iguchi T, Miyagawa S. Comparative analysis of gonadal transcriptomes between turtle and alligator identifies common molecular cues activated during the temperature-sensitive period for sex determination. Gene 2023; 888:147763. [PMID: 37666375 DOI: 10.1016/j.gene.2023.147763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/09/2023] [Accepted: 09/01/2023] [Indexed: 09/06/2023]
Abstract
The mode of sex determination in vertebrates can be categorized as genotypic or environmental. In the case of genotypic sex determination (GSD), the sexual fate of an organism is determined by the chromosome composition with some having dominant genes, named sex-determining genes, that drive the sex phenotypes. By contrast, many reptiles exhibit environmental sex determination (ESD), whereby environmental stimuli drive sex determination, and most notably temperature. To date, temperature-dependent sex determination (TSD) has been found in most turtles, some lizards, and all crocodylians, but commonalities in the controlling processes are not well established. Recent innovative sequencing technology has enabled investigations into gonadal transcriptomic profiles during temperature-sensitive periods (TSP) in various TSD species which can help elucidate the controlling mechanisms. In this study, we conducted a time-course analysis of the gonadal transcriptome during the male-producing temperature (26℃) of the Reeve's turtle (Chinese three-keeled pond turtle) Mauremys reevesii. We then compared the transcriptome profiles for this turtle species during the TSP with that for the American alligator Alligator mississippiensis to identify conserved reptilian TSD-related genes. Our transcriptome-based findings provide an opportunity to retrieve the candidate molecular cues that are activated during TSP and compare these target responses between TSD and GSD turtle species, and between TSD species.
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Affiliation(s)
- Kenji Toyota
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan; Noto Marine Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Ogi, Noto-cho, Ishikawa 927-0553, Japan; Department of Biological Sciences, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka, Kanagawa 259-1293, Japan.
| | - Hiroshi Akashi
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan; Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan
| | - Momoka Ishikawa
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Katsushi Yamaguchi
- Trans-Omics Facility, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji-cho, Okazaki, Aichi 444-8585, Japan
| | - Shuji Shigenobu
- Trans-Omics Facility, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji-cho, Okazaki, Aichi 444-8585, Japan
| | - Tomomi Sato
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, Kanagawa 236-0027, Japan
| | - Anke Lange
- Biosciences, Faculty of Health and Life Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Charles R Tyler
- Biosciences, Faculty of Health and Life Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Taisen Iguchi
- Noto Marine Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Ogi, Noto-cho, Ishikawa 927-0553, Japan; Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, Kanagawa 236-0027, Japan
| | - Shinichi Miyagawa
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
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12
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Yao ZL, Fang QF, Li JY, Zhou M, Du S, Chen HJ, Wang H, Jiang SJ, Wang X, Zhao Y, Ji XS. Alternative splicing of histone demethylase Kdm6bb mediates temperature-induced sex reversal in the Nile tilapia. Curr Biol 2023; 33:5057-5070.e5. [PMID: 37995698 DOI: 10.1016/j.cub.2023.10.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 09/05/2023] [Accepted: 10/23/2023] [Indexed: 11/25/2023]
Abstract
Sex determination in many fish species is remarkably plastic and temperature sensitive. Nile tilapia display a genetic sex-determination system (XX/XY). However, high-temperature treatment during critical thermosensitive periods can induce XX females into XXm pseudo-males, and this phenomenon is termed temperature-induced sex reversal (TISR). To investigate the molecular mechanism of TISR in Nile tilapia, we performed Iso-seq analysis and found a dramatic effect of high temperature on gene alternative splicing (AS). Kdm6bb histone demethylase showed a novel AS at intron 5 that generates Kdm6bb_tv1 transcripts without intron 5 and Kdm6bb_tv2 with intron 5. Kdm6bb_tv1 encodes a full-length protein while Kdm6bb_tv2 encodes a truncated protein. Expression analysis revealed that intron 5 splicing of Kdm6bb is male and gonad biased at larval stage, and only gonad biased at adult stage. High-temperature treatment induced intron 5 splicing in the gonads of XX and XY fish, resulting in increased Kdm6bb_tv1 expression. To directly test the role of Kdm6bb_tv1 in Nile tilapia TISR, we knocked out expression of Kdm6bb_tv1. However, Kdm6bb_tv1-/- homozygous mutants showed embryonic lethality. Overexpression of Kdm6bb_tv1, but not Kdm6bb_tv2, induced sex reversal of XX females into pseudo-males. Overexpression of Kdm6bb_tv1, as with high-temperature treatment, modified the promotor region of Gsdf and Dmrt1 by demethylating the trimethylated lysine 27 of histone 3 (H3K27me3), thereby increasing expression. Collectively, these studies demonstrate that AS of Kdm6bb intron 5 increases the expression of Kdm6bb_tv1, which acts as a direct link between high temperature and activation of Gsdf and Dmrt1 expression, leading to male sex determination.
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Affiliation(s)
- Zhi Lei Yao
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271018, Shandong, China; Key Laboratory of Efficient Utilization of Non-grain Feed Resources (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Shandong Agricultural University, Taian 271018, Shandong, China
| | - Qing Feng Fang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271018, Shandong, China; Key Laboratory of Efficient Utilization of Non-grain Feed Resources (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Shandong Agricultural University, Taian 271018, Shandong, China
| | - Jia Yue Li
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271018, Shandong, China; Key Laboratory of Efficient Utilization of Non-grain Feed Resources (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Shandong Agricultural University, Taian 271018, Shandong, China
| | - Min Zhou
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271018, Shandong, China; Key Laboratory of Efficient Utilization of Non-grain Feed Resources (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Shandong Agricultural University, Taian 271018, Shandong, China
| | - Shaojun Du
- Department of Biochemistry and Molecular Biology, Institute of Marine and Environmental Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Hong Ju Chen
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271018, Shandong, China; Key Laboratory of Efficient Utilization of Non-grain Feed Resources (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Shandong Agricultural University, Taian 271018, Shandong, China
| | - Hui Wang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271018, Shandong, China; Key Laboratory of Efficient Utilization of Non-grain Feed Resources (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Shandong Agricultural University, Taian 271018, Shandong, China
| | - Shi-Jin Jiang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271018, Shandong, China; Key Laboratory of Efficient Utilization of Non-grain Feed Resources (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Shandong Agricultural University, Taian 271018, Shandong, China
| | - Xiao Wang
- Library, Shandong Agricultural University, Taian 271018, Shandong, China
| | - Yan Zhao
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271018, Shandong, China; Key Laboratory of Efficient Utilization of Non-grain Feed Resources (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Shandong Agricultural University, Taian 271018, Shandong, China.
| | - Xiang Shan Ji
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271018, Shandong, China; Key Laboratory of Efficient Utilization of Non-grain Feed Resources (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Shandong Agricultural University, Taian 271018, Shandong, China.
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13
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Valli FE, Simoncini MS, González MA, Piña CI. How do maternal androgens and estrogens affect sex determination in reptiles with temperature-dependent sex? Dev Growth Differ 2023; 65:565-576. [PMID: 37603030 DOI: 10.1111/dgd.12887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 08/22/2023]
Abstract
Temperature sex determination (TSD) in reptiles has been studied to elucidate the mechanisms by which temperature is transformed into a biological signal that determines the sex of the embryo. Temperature is thought to trigger signals that alter gene expression and hormone metabolism, which will determine the development of female or male gonads. In this review, we focus on collecting and discussing important and recent information on the role of maternal steroid hormones in sex determination in oviparous reptiles such as crocodiles, turtles, and lizards that possess TSD. In particular, we focus on maternal androgens and estrogens deposited in the egg yolk and their metabolites that could also influence the sex of offspring. Finally, we suggest guidelines for future research to help clarify the link between maternal steroid hormones and offspring sex.
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Affiliation(s)
- Florencia E Valli
- CICYTTP-CONICET/Prov. Entre Ríos/UADER, Diamante, Argentina
- Departamento de Ciencias Biológicas, Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Melina S Simoncini
- CICYTTP-CONICET/Prov. Entre Ríos/UADER, Diamante, Argentina
- Facultad de Ciencia y Tecnología, Universidad Autónoma de Entre Ríos, Diamante, Argentina
| | - Marcela A González
- Departamento de Ciencias Biológicas, Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Carlos I Piña
- CICYTTP-CONICET/Prov. Entre Ríos/UADER, Diamante, Argentina
- Facultad de Ciencia y Tecnología, Universidad Autónoma de Entre Ríos, Diamante, Argentina
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14
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Breitenbach AT, Marroquín-Flores RA, Paitz RT, Bowden RM. Experiencing short heat waves early in development changes thermal responsiveness of turtle embryos to later heat waves. J Exp Biol 2023; 226:jeb246235. [PMID: 37661755 PMCID: PMC10560553 DOI: 10.1242/jeb.246235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 08/17/2023] [Indexed: 09/05/2023]
Abstract
Although physiological responses to the thermal environment are most frequently investigated using constant temperatures, the incorporation of thermal variability can allow for a more accurate prediction of how thermally sensitive species respond to a rapidly changing climate. In species with temperature-dependent sex determination (TSD), developmental responses to incubation temperature are mediated by several genes involved in gonadal differentiation. Kdm6b and Dmrt1 respond to cool incubation temperatures and are associated with testis development, while FoxL2 and Cyp19A1 respond to warm incubation temperatures and are associated with ovary development. Using fluctuating incubation temperatures, we designed two studies, one investigating how conflicting thermal cues affect the timing of commitment to gonadal development, and another investigating the rapid molecular responses to conflicting thermal cues in the red-eared slider turtle (Trachemys scripta). Using gene expression as a proxy of timing of commitment to gonadal fate, results from the first study show that exposure to high amounts of conflicting thermal cues during development delays commitment to gonadal fate. Results from the second study show that Kdm6b splice variants exhibit differential responses to early heat wave exposure, but rapidly (within 2 days) recover to pre-exposure levels after the heat wave. Despite changes in the expression of Kdm6b splice variants, there was no effect on Dmrt1 expression. Collectively, these findings demonstrate how short exposures to heat early in development can change how embryos respond to heat later in development.
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Affiliation(s)
- Anthony T. Breitenbach
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
| | - Rosario A. Marroquín-Flores
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - Ryan T. Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Rachel M. Bowden
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
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15
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Wagner S, Whiteley SL, Castelli M, Patel HR, Deveson IW, Blackburn J, Holleley CE, Marshall Graves JA, Georges A. Gene expression of male pathway genes sox9 and amh during early sex differentiation in a reptile departs from the classical amniote model. BMC Genomics 2023; 24:243. [PMID: 37147622 PMCID: PMC10163765 DOI: 10.1186/s12864-023-09334-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 04/25/2023] [Indexed: 05/07/2023] Open
Abstract
BACKGROUND Sex determination is the process whereby the bipotential embryonic gonads become committed to differentiate into testes or ovaries. In genetic sex determination (GSD), the sex determining trigger is encoded by a gene on the sex chromosomes, which activates a network of downstream genes; in mammals these include SOX9, AMH and DMRT1 in the male pathway, and FOXL2 in the female pathway. Although mammalian and avian GSD systems have been well studied, few data are available for reptilian GSD systems. RESULTS We conducted an unbiased transcriptome-wide analysis of gonad development throughout differentiation in central bearded dragon (Pogona vitticeps) embryos with GSD. We found that sex differentiation of transcriptomic profiles occurs at a very early stage, before the gonad consolidates as a body distinct from the gonad-kidney complex. The male pathway genes dmrt1 and amh and the female pathway gene foxl2 play a key role in early sex differentiation in P. vitticeps, but the central player of the mammalian male trajectory, sox9, is not differentially expressed in P. vitticeps at the bipotential stage. The most striking difference from GSD systems of other amniotes is the high expression of the male pathway genes amh and sox9 in female gonads during development. We propose that a default male trajectory progresses if not repressed by a W-linked dominant gene that tips the balance of gene expression towards the female trajectory. Further, weighted gene expression correlation network analysis revealed novel candidates for male and female sex differentiation. CONCLUSION Our data reveal that interpretation of putative mechanisms of GSD in reptiles cannot solely depend on lessons drawn from mammals.
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Affiliation(s)
- Susan Wagner
- Institute for Applied Ecology, University of Canberra, Bruce, ACT, Australia
| | - Sarah L Whiteley
- Institute for Applied Ecology, University of Canberra, Bruce, ACT, Australia
- Australian National Wildlife Collection CSIRO, National Research Collections Australia, Crace, ACT, Australia
| | - Meghan Castelli
- Institute for Applied Ecology, University of Canberra, Bruce, ACT, Australia
- Australian National Wildlife Collection CSIRO, National Research Collections Australia, Crace, ACT, Australia
| | - Hardip R Patel
- Genome Sciences Department. John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Ira W Deveson
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
- Faculty of Medicine, St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - James Blackburn
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
- Faculty of Medicine, St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Clare E Holleley
- Institute for Applied Ecology, University of Canberra, Bruce, ACT, Australia
- Australian National Wildlife Collection CSIRO, National Research Collections Australia, Crace, ACT, Australia
| | - Jennifer A Marshall Graves
- Institute for Applied Ecology, University of Canberra, Bruce, ACT, Australia
- School of Life Sciences, La Trobe University, Bundoora, VIC, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Bruce, ACT, Australia.
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16
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Waters PD, Graves JAM, Whiteley SL, Georges A, Ruiz-Herrera A. Three dimensions of thermolabile sex determination. Bioessays 2023; 45:e2200123. [PMID: 36529688 DOI: 10.1002/bies.202200123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 10/14/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022]
Abstract
The molecular mechanism of temperature-dependent sex determination (TSD) is a long-standing mystery. How is the thermal signal sensed, captured and transduced to regulate key sex genes? Although there is compelling evidence for pathways via which cells capture the temperature signal, there is no known mechanism by which cells transduce those thermal signals to affect gene expression. Here we propose a novel hypothesis we call 3D-TSD (the three dimensions of thermolabile sex determination). We postulate that the genome has capacity to remodel in response to temperature by changing 3D chromatin conformation, perhaps via temperature-sensitive transcriptional condensates. This could rewire enhancer-promoter interactions to alter the expression of key sex-determining genes. This hypothesis can accommodate monogenic or multigenic thermolabile sex-determining systems, and could be combined with upstream thermal sensing and transduction to the epigenome to commit gonadal fate.
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Affiliation(s)
- Paul D Waters
- Faculty of Science, School of Biotechnology and Biomolecular Science, UNSW Sydney, Sydney, NSW, Australia
| | - Jennifer A Marshall Graves
- Department of Environment and Genetics, La Trobe University, Bundoora, Australia.,Institute for Applied Ecology, University of Canberra, Canberra, Australia
| | - Sarah L Whiteley
- Institute for Applied Ecology, University of Canberra, Canberra, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, Australia
| | - Aurora Ruiz-Herrera
- Departament de Biologia Cellular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.,Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
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17
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Li S, Li W, Jiang S, Jing Y, Xiao L, Yu Y, Liu Y, Li Y, Wang D, Li J, Peng C, Chen J, Lu D, Wu B, Guang X, Ma J, You X, Yang Y, Liu S, Fang X, Gao Q, Shi Q, Lin H, Schartl M, Yue Z, Zhang Y. Mechanisms of sex differentiation and sex reversal in hermaphrodite fish as revealed by the Epinephelus coioides genome. Mol Ecol Resour 2023; 23:920-932. [PMID: 36631404 DOI: 10.1111/1755-0998.13753] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 12/13/2022] [Accepted: 12/28/2022] [Indexed: 01/13/2023]
Abstract
Most grouper species are functional protogynous hermaphrodites, but the genetic basis and the molecular mechanisms underlying the regulation of this unique reproductive strategy remain enigmatic. In this study, we report a high-quality chromosome-level genome assembly of the representative orange-spotted grouper (Epinephelus coioides). No duplication or deletion of sex differentiation-related genes was found in the genome, suggesting that sex development in this grouper may be related to changes in regulatory sequences or environmental factors. Transcriptomic analyses showed that aromatase and retinoic acid are probably critical to promoting ovarian fate determination, and follicle-stimulating hormone triggers the female-to-male sex change. Socially controlled sex-change studies revealed that, in sex-changing fish, the brain's response to the social environment may be mediated by activation of the phototransduction cascade and the melatonin synthesis pathway. In summary, our genomic and experimental results provide novel insights into the molecular mechanisms of sex differentiation and sex change in the protogynous groupers.
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Affiliation(s)
- Shuisheng Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | | | - Shoujia Jiang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.,Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, Shenzhen, China
| | - Yi Jing
- BGI-Shenzhen, Shenzhen, China.,BGI-Sanya, BGI-Shenzhen, Sanya, China
| | - Ling Xiao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | | | - Yun Liu
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Yanhong Li
- BGI Genomics, BGI-Shenzhen, Shenzhen, China
| | - Dengdong Wang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Jiang Li
- BGI Genomics, BGI-Shenzhen, Shenzhen, China
| | - Cheng Peng
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Jiaxing Chen
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Danqi Lu
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Bin Wu
- BGI-Shenzhen, Shenzhen, China
| | | | - Junping Ma
- BGI Genomics, BGI-Shenzhen, Shenzhen, China
| | - Xinxin You
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, Shenzhen, China
| | - Yuqing Yang
- Marine Fisheries Development Center of Guangdong Province, Huizhou, China
| | - Su Liu
- Marine Fisheries Development Center of Guangdong Province, Huizhou, China
| | | | - Qiang Gao
- BGI Genomics, BGI-Shenzhen, Shenzhen, China
| | - Qiong Shi
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, Shenzhen, China
| | - Haoran Lin
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Manfred Schartl
- Developmental Biochemistry, University of Würzburg, Biozentrum, Am Hubland, Würzburg, and Comprehensive Cancer Center, University Clinic Würzburg, Würzburg, Germany.,Hagler Institute for Advanced Study and Department of Biology, Texas A&M University, College Station, Texas, USA
| | - Zhen Yue
- BGI-Shenzhen, Shenzhen, China.,BGI-Sanya, BGI-Shenzhen, Sanya, China
| | - Yong Zhang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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18
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Smaga CR, Bock SL, Johnson JM, Parrott BB. Sex Determination and Ovarian Development in Reptiles and Amphibians: From Genetic Pathways to Environmental Influences. Sex Dev 2022; 17:99-119. [PMID: 36380624 DOI: 10.1159/000526009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 07/08/2022] [Indexed: 11/21/2023] Open
Abstract
BACKGROUND Reptiles and amphibians provide untapped potential for discovering how a diversity of genetic pathways and environmental conditions are incorporated into developmental processes that can lead to similar functional outcomes. These groups display a multitude of reproductive strategies, and whereas many attributes are conserved within groups and even across vertebrates, several aspects of sexual development show considerable variation. SUMMARY In this review, we focus our attention on the development of the reptilian and amphibian ovary. First, we review and describe the events leading to ovarian development, including sex determination and ovarian maturation, through a comparative lens. We then describe how these events are influenced by environmental factors, focusing on temperature and exposure to anthropogenic chemicals. Lastly, we identify critical knowledge gaps and future research directions that will be crucial to moving forward in our understanding of ovarian development and the influences of the environment in reptiles and amphibians. KEY MESSAGES Reptiles and amphibians provide excellent models for understanding the diversity of sex determination strategies and reproductive development. However, a greater understanding of the basic biology of these systems is necessary for deciphering the adaptive and potentially disruptive implications of embryo-by-environment interactions in a rapidly changing world.
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Affiliation(s)
- Christopher R Smaga
- Eugene P. Odum School of Ecology, University of Georgia, Athens, Georgia, USA
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
| | - Samantha L Bock
- Eugene P. Odum School of Ecology, University of Georgia, Athens, Georgia, USA
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
| | - Josiah M Johnson
- Eugene P. Odum School of Ecology, University of Georgia, Athens, Georgia, USA
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
| | - Benjamin B Parrott
- Eugene P. Odum School of Ecology, University of Georgia, Athens, Georgia, USA
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
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19
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Zhou M, Yao Z, Zhao M, Fang Q, Ji X, Chen H, Zhao Y. Molecular Cloning and Expression Responses of Jarid2b to High-Temperature Treatment in Nile Tilapia ( Oreochromis niloticus). Genes (Basel) 2022; 13:1719. [PMID: 36292604 PMCID: PMC9602145 DOI: 10.3390/genes13101719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/12/2022] [Accepted: 09/20/2022] [Indexed: 10/27/2023] Open
Abstract
Nile tilapia is a GSD + TE (Genetic Sex Determination + Temperature Effect) fish, and high-temperature treatment during critical thermosensitive periods (TSP) can induce the sex reversal of Nile tilapia genetic females, and brain transcriptomes have revealed the upregulation of Jarid2 (Jumonji and AT-rich domain containing 2) expression after 36 °C high-temperature treatment for 12 days during TSP. It was shown that JARID2 forms a complex with polycomb repressive complex 2 (PRC2) that catalyzed H3K27me3, which was strongly associated with transcriptional repression. In this study, Jarid2b was cloned and characterized in Nile tilapia, which was highly conserved among the analyzed fish species. The expression of Jarid2b was upregulated in the gonad of 21 dpf XX genetic females after 12-day high-temperature treatment and reached a similar level to that of males. Similar responses to high-temperature treatment also appeared in the brain, heart, liver, muscle, eye, and skin tissues. Interestingly, Jarid2b expression was only in response to high-temperature treatment, and not to 17α-methyltestosterone (MT) or letrozole treatments; although, these treatments can also induce the sex reversal of genetic Nile tilapia females. Further studies revealed that Jarid2b responded rapidly at the 8th hour after high-temperature treatment. Considering that JARID2 can recruit PRC2 and establish H3K27me3, we speculated that it might be an upstream gene participating in the regulation of Nile tilapia GSD + TE through regulating the H3K27 methylation level at the locus of many sex differentiation-related genes.
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Affiliation(s)
| | | | | | | | | | | | - Yan Zhao
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China
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20
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Marroquín-Flores RA, Paitz RT, Bowden RM. Temperature fluctuations and estrone sulfate affect gene expression via different mechanisms to promote female development in a species with temperature-dependent sex determination. J Exp Biol 2022; 225:276050. [PMID: 35860927 DOI: 10.1242/jeb.244211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/18/2022] [Indexed: 11/20/2022]
Abstract
Variation in developmental conditions can affect a variety of embryonic processes and shape a number of phenotypic characteristics that can affect offspring throughout their lives. This is particularly true of oviparous species where development typically occurs outside of the female, and studies have shown that traits such as survival and behavior can be altered by both temperature and exposure to steroid hormones during development. In species with temperature-dependent sex determination (TSD), the fate of gonadal development can be affected by temperature and by maternal estrogens present in the egg at oviposition and there is evidence that these factors can affect gene expression patterns. Here, we explore how thermal fluctuations and exposure to an estrogen metabolite, estrone sulfate, affect the expression of several genes known to be involved in sexual differentiation; Kdm6b, Dmrt1, Sox9, FoxL2, and Cyp19A1. We found that most of the genes responded to both temperature and estrone sulfate exposure, but that the responses to these factors was not identical in that estrone sulfate effects occur downstream of temperature effects. Our findings demonstrate that conjugated hormones such as estrone sulfate are capable of influencing temperature dependent pathways to potentially alter how embryos respond to temperature and highlight the importance of studying the interaction of maternal hormone and temperature effects.
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Affiliation(s)
| | - Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Rachel M Bowden
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
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21
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Suárez-Varón G, Mendoza-Cruz E, Acosta A, Villagrán-Santa Cruz M, Cortez D, Hernández-Gallegos O. Genetic determination and JARID2 over-expression in a thermal incubation experiment in Casque-Headed Lizard. PLoS One 2022; 17:e0263804. [PMID: 35797377 PMCID: PMC9262179 DOI: 10.1371/journal.pone.0263804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 06/16/2022] [Indexed: 11/19/2022] Open
Abstract
Non-avian reptiles, unlike mammals and birds, have undergone numerous sex determination changes. Casque-Headed Lizards have replaced the ancestral XY system shared across pleurodonts with a new pair of XY chromosomes. However, the evolutionary forces that triggered this transition have remained unclear. An interesting hypothesis suggests that species with intermediate states, with sex chromosomes but also thermal-induced sex reversal at specific incubation temperatures, could be more susceptible to sex determination turnovers. We contrasted genotypic data (presence/absence of the Y chromosome) against the histology of gonads of embryos from stages 35–37 incubated at various temperatures, including typical male-producing (26°C) and female-producing (32°C) temperatures. Our work apparently reports for the first time the histology of gonads, including morphological changes, from stages 35–37 of development in the family Corytophanidae. We also observed that all embryos developed hemipenes, suggesting sex-linked developmental heterochrony. We observed perfect concordance between genotype and phenotype at all temperatures. However, analysis of transcriptomic data from embryos incubated at 26°C and 32°C identified transcript variants of the chromatin modifiers JARID2 and KDM6B that have been linked to temperature-dependent sex determination in other reptiles. Our work tested the validity of a mixed sex determination system in the family Corytophanidae. We found that XY chromosomes are dominant; however, our work supports the hypothesis of a conserved transcriptional response to incubation temperatures across non-avian reptiles that could be a reminiscence of an ancestral sex determination system.
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Affiliation(s)
- Gabriel Suárez-Varón
- Laboratorio de Herpetología, Facultad de Ciencias, Universidad Autónoma del Estado de México, Instituto Literario # 100 Centro, Toluca, Estado de México, México
| | - Eva Mendoza-Cruz
- Laboratorio de Biología Tisular y Reproductora, Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, México
| | | | - Maricela Villagrán-Santa Cruz
- Laboratorio de Biología Tisular y Reproductora, Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Diego Cortez
- Centro de Ciencias Genómicas, UNAM, Cuernavaca, México
- * E-mail:
| | - Oswaldo Hernández-Gallegos
- Laboratorio de Herpetología, Facultad de Ciencias, Universidad Autónoma del Estado de México, Instituto Literario # 100 Centro, Toluca, Estado de México, México
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22
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Paitz RT, Breitenbach AT, Marroquín-Flores RA, Bowden RM. Understanding how variable thermal environments affect the molecular mechanisms underlying temperature-sensitive phenotypes: lessons from sex determination. J Exp Biol 2022; 225:275566. [PMID: 35638467 DOI: 10.1242/jeb.242373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The thermal environment that organisms experience can affect many aspects of their phenotype. As global temperatures become more unpredictable, it is imperative that we understand the molecular mechanisms by which organisms respond to variable, and often transient, thermal environments. Beyond deciphering the mechanisms through which organisms respond to temperature, we must also appreciate the underlying variation in temperature-dependent processes, as this variation is essential for understanding the potential to adapt to changing climates. In this Commentary, we use temperature-dependent sex determination as an example to explore the mechanistic processes underlying the development of temperature-sensitive phenotypes. We synthesize the current literature on how variable thermal conditions affect these processes and address factors that may limit or allow organisms to respond to variable environments. From these examples, we posit a framework for how the field might move forward in a more systematic way to address three key questions: (1) which genes directly respond to temperature-sensitive changes in protein function and which genes are downstream, indirect responders?; (2) how long does it take different proteins and genes to respond to temperature?; and (3) are the experimental temperature manipulations relevant to the climate the organism experiences or to predicted climate change scenarios? This approach combines mechanistic questions (questions 1 and 2) with ecologically relevant conditions (question 3), allowing us to explore how organisms respond to transient thermal environments and, thus, cope with climate change.
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Affiliation(s)
- Ryan T Paitz
- Illinois State University, Normal, IL 61790, USA
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23
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Whiteley SL, Holleley CE, Georges A. Developmental dynamics of sex reprogramming by high incubation temperatures in a dragon lizard. BMC Genomics 2022; 23:322. [PMID: 35459109 PMCID: PMC9034607 DOI: 10.1186/s12864-022-08544-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 04/08/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In some vertebrate species, gene-environment interactions can determine sex, driving bipotential gonads to differentiate into either ovaries or testes. In the central bearded dragon (Pogona vitticeps), the genetic influence of sex chromosomes (ZZ/ZW) can be overridden by high incubation temperatures, causing ZZ male to female sex reversal. Previous research showed ovotestes, a rare gonadal phenotype with traits of both sexes, develop during sex reversal, leading to the hypothesis that sex reversal relies on high temperature feminisation to outcompete the male genetic cue. To test this, we conducted temperature switching experiments at key developmental stages, and analysed the effect on gonadal phenotypes using histology and transcriptomics. RESULTS We found sexual fate is more strongly influenced by the ZZ genotype than temperature. Any exposure to low temperatures (28 °C) caused testes differentiation, whereas sex reversal required longer exposure to high temperatures. We revealed ovotestes exist along a spectrum of femaleness to male-ness at the transcriptional level. We found inter-individual variation in gene expression changes following temperature switches, suggesting both genetic sensitivity to, and the timing and duration of the temperature cue influences sex reversal. CONCLUSIONS These findings bring new insights to the mechanisms underlying sex reversal, improving our understanding of thermosensitive sex systems in vertebrates.
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Affiliation(s)
- Sarah L Whiteley
- Institute for Applied Ecology, University of Canberra, Canberra, Australia.
- Australian National Wildlife Collection, CSIRO, Canberra, Australia.
| | - Clare E Holleley
- Australian National Wildlife Collection, CSIRO, Canberra, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, Australia
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24
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Whiteley SL, Wagner S, Holleley CE, Deveson IW, Marshall Graves JA, Georges A. Truncated jarid2 and kdm6b transcripts are associated with temperature-induced sex reversal during development in a dragon lizard. SCIENCE ADVANCES 2022; 8:eabk0275. [PMID: 35442724 PMCID: PMC9020659 DOI: 10.1126/sciadv.abk0275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 03/04/2022] [Indexed: 05/23/2023]
Abstract
Sex determination and differentiation in reptiles are complex. In the model species, Pogona vitticeps, high incubation temperature can cause male to female sex reversal. To elucidate the epigenetic mechanisms of thermolabile sex, we used an unbiased genome-wide assessment of intron retention during sex reversal. The previously implicated chromatin modifiers (jarid2 and kdm6b) were two of three genes to display sex reversal-specific intron retention. In these species, embryonic intron retention resulting in C-terminally truncated jarid2 and kdm6b isoforms consistently occurs at low temperatures. High-temperature sex reversal is uniquely characterized by a high prevalence of N-terminally truncated isoforms of jarid2 and kdm6b, which are not present at low temperatures, or in two other reptiles with temperature-dependent sex determination. This work verifies that chromatin-modifying genes are involved in highly conserved temperature responses and can also be transcribed into isoforms with new sex-determining roles.
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Affiliation(s)
- Sarah L. Whiteley
- Institute for Applied Ecology, University of Canberra, Bruce, Australia
- Australian National Wildlife Collection, CSIRO National Research Collections Australia, Canberra, Australia
| | - Susan Wagner
- Institute for Applied Ecology, University of Canberra, Bruce, Australia
| | - Clare E. Holleley
- Australian National Wildlife Collection, CSIRO National Research Collections Australia, Canberra, Australia
| | - Ira W. Deveson
- Garvan Institute of Medical Research, Sydney, Australia
- St. Vincent’s Clinical School, UNSW, Sydney, Australia
| | | | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Bruce, Australia
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25
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Breitenbach AT, Bowden RM, Paitz RT. Effects of Constant and Fluctuating Temperatures on Gene Expression During Gonadal Development. Integr Comp Biol 2022; 62:21-29. [PMID: 35325145 DOI: 10.1093/icb/icac011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
There is ample research demonstrating that temperature can have complex effects on biological processes, including the timing of when organisms respond to temperature; some responses occur rapidly while others require an extended exposure time. However, most of what we know about temperature effects comes from studies using constant temperature conditions, which are not reflective of natural, fluctuating temperatures. Species with temperature-dependent sex determination (TSD) present an ideal system to study the temporal aspects of the temperature response because prior research has established a number of temperature-responsive genes involved in TSD, albeit under constant temperatures. To investigate potential differences in timing of sexual development between constant and fluctuating incubation temperatures, we exposed Trachemys scripta embryos to two conditions that produce males (constant 26 °C and 26 ± 3 °C) and two that produce females (constant 31 °C and 31 ± 3 °C) and sampled embryonic gonads for gene expression analysis via qPCR. We analyzed three genes involved in testis differentiation (Kdm6b, Dmrt1, and Sox9) and two genes involved in ovary differentiation (Foxl2 and Cyp19A1). Results show that Kdm6b expression was significantly lower under fluctuating temperatures compared to constant temperatures. Foxl2 and Cyp19A1 expression were also lower under fluctuating temperatures, but not at all stages of development. These results suggest that constant temperatures caused increases in both Foxl2 and Cyp19A1 expression earlier (developmental stage 20) than fluctuating temperatures (stages 22-23). Dmrt1 and Sox9 expression did not differ between constant and fluctuating temperatures. These results highlight that not all genes in a temperature-dependent process respond to temperature in the same manner. Whether there are functional consequences of this variation remains to be determined.
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Affiliation(s)
| | - Rachel M Bowden
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
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26
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Bélanger C, Cardinal T, Leduc E, Viger RS, Pilon N. CHARGE syndrome-associated proteins FAM172A and CHD7 influence male sex determination and differentiation through transcriptional and alternative splicing mechanisms. FASEB J 2022; 36:e22176. [PMID: 35129866 PMCID: PMC9304217 DOI: 10.1096/fj.202100837rr] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 01/05/2022] [Accepted: 01/10/2022] [Indexed: 11/11/2022]
Abstract
To gain further insight into chromatin‐mediated regulation of mammalian sex determination, we analyzed the role of the CHARGE syndrome‐associated proteins FAM172A and CHD7. This study is based on our prior discoveries that a subset of corresponding mutant mice display complete male‐to‐female sex reversal, and that both of these proteins regulate co‐transcriptional alternative splicing in neural crest cells. Here, we report that FAM172A and CHD7 are present in the developing gonads when sex determination normally occurs in mice. The interactome of FAM172A in pre‐Sertoli cells again suggests a role at the chromatin‐spliceosome interface, like in neural crest cells. Accordingly, analysis of Fam172a‐mutant pre‐Sertoli cells revealed transcriptional and splicing dysregulation of hundreds of genes. Many of these genes are similarly affected in Chd7‐mutant pre‐Sertoli cells, including several known key regulators of sex determination and subsequent formation of testis cords. Among them, we notably identified Sry as a direct transcriptional target and WNT pathway‐associated Lef1 and Tcf7l2 as direct splicing targets. The identified molecular defects are also associated with the abnormal morphology of seminiferous tubules in mutant postnatal testes. Altogether, our results thus identify FAM172A and CHD7 as new players in the regulation of male sex determination and differentiation in mice, and further highlight the importance of chromatin‐mediated regulatory mechanisms in these processes.
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Affiliation(s)
- Catherine Bélanger
- Molecular Genetics of Development Laboratory, Département des Sciences Biologiques, Université du Québec à Montréal (UQAM), Montréal, Québec, Canada.,Centre d'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois (CERMO-FC), Université du Québec à Montréal, Montréal, Québec, Canada
| | - Tatiana Cardinal
- Molecular Genetics of Development Laboratory, Département des Sciences Biologiques, Université du Québec à Montréal (UQAM), Montréal, Québec, Canada.,Centre d'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois (CERMO-FC), Université du Québec à Montréal, Montréal, Québec, Canada
| | - Elizabeth Leduc
- Molecular Genetics of Development Laboratory, Département des Sciences Biologiques, Université du Québec à Montréal (UQAM), Montréal, Québec, Canada.,Centre d'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois (CERMO-FC), Université du Québec à Montréal, Montréal, Québec, Canada
| | - Robert S Viger
- Reproduction, Mother and Child Health, Centre de recherche en reproduction, développement et santé intergénérationnelle (CRDSI), Centre de recherche du CHU de Québec-Université Laval, Quebec City, Québec, Canada.,Department of Obstetrics, Gynecology, and Reproduction, Faculty of Medicine, Université Laval, Quebec City, Québec, Canada
| | - Nicolas Pilon
- Molecular Genetics of Development Laboratory, Département des Sciences Biologiques, Université du Québec à Montréal (UQAM), Montréal, Québec, Canada.,Centre d'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois (CERMO-FC), Université du Québec à Montréal, Montréal, Québec, Canada.,Département de pédiatrie, Université de Montréal, Montréal, Québec, Canada
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Zhang X, Wagner S, Holleley CE, Deakin JE, Matsubara K, Deveson IW, O'Meally D, Patel HR, Ezaz T, Li Z, Wang C, Edwards M, Graves JAM, Georges A. Sex-specific splicing of Z- and W-borne nr5a1 alleles suggests sex determination is controlled by chromosome conformation. Proc Natl Acad Sci U S A 2022; 119:e2116475119. [PMID: 35074916 PMCID: PMC8795496 DOI: 10.1073/pnas.2116475119] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 12/03/2021] [Indexed: 11/18/2022] Open
Abstract
Pogona vitticeps has female heterogamety (ZZ/ZW), but the master sex-determining gene is unknown, as it is for all reptiles. We show that nr5a1 (Nuclear Receptor Subfamily 5 Group A Member 1), a gene that is essential in mammalian sex determination, has alleles on the Z and W chromosomes (Z-nr5a1 and W-nr5a1), which are both expressed and can recombine. Three transcript isoforms of Z-nr5a1 were detected in gonads of adult ZZ males, two of which encode a functional protein. However, ZW females produced 16 isoforms, most of which contained premature stop codons. The array of transcripts produced by the W-borne allele (W-nr5a1) is likely to produce truncated polypeptides that contain a structurally normal DNA-binding domain and could act as a competitive inhibitor to the full-length intact protein. We hypothesize that an altered configuration of the W chromosome affects the conformation of the primary transcript generating inhibitory W-borne isoforms that suppress testis determination. Under this hypothesis, the genetic sex determination (GSD) system of P. vitticeps is a W-borne dominant female-determining gene that may be controlled epigenetically.
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Affiliation(s)
- Xiuwen Zhang
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
| | - Susan Wagner
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
| | - Clare E Holleley
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
- Australian National Wildlife Collection, Commonwealth Scientific and Industrial Research Organisation, Crace, ACT 2911, Australia
| | - Janine E Deakin
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
| | - Kazumi Matsubara
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
| | - Ira W Deveson
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales, Sydney, NSW 2052, Australia
| | - Denis O'Meally
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
| | - Hardip R Patel
- Genome Sciences Department, John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia
| | - Tariq Ezaz
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
| | - Zhao Li
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
| | - Chexu Wang
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
| | - Melanie Edwards
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
| | - Jennifer A Marshall Graves
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia;
- School of Life Sciences, La Trobe University, Bundoora, VIC 3186, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia;
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28
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Liu X, Zhou L, Luo B, Qian H, Ye B, Ma K, Qiu G. Identification of novel Z/W chromosome-specific markers from the giant freshwater prawn Macrobrachium rosenbergii. AQUACULTURE AND FISHERIES 2022. [DOI: 10.1016/j.aaf.2022.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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29
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Becskei A, Rahaman S. The life and death of RNA across temperatures. Comput Struct Biotechnol J 2022; 20:4325-4336. [PMID: 36051884 PMCID: PMC9411577 DOI: 10.1016/j.csbj.2022.08.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/04/2022] [Accepted: 08/04/2022] [Indexed: 11/05/2022] Open
Abstract
Temperature is an environmental condition that has a pervasive effect on cells along with all the molecules and reactions in them. The mechanisms by which prototypical RNA molecules sense and withstand heat have been identified mostly in bacteria and archaea. The relevance of these phenomena is, however, broader, and similar mechanisms have been recently found throughout the tree of life, from sex determination in reptiles to adaptation of viral RNA polymerases, to genetic disorders in humans. We illustrate the temperature dependence of RNA metabolism with examples from the synthesis to the degradation of mRNAs, and review recently emerged questions. Are cells exposed to greater temperature variations and gradients than previously surmised? How do cells reconcile the conflicting thermal stability requirements of primary and tertiary structures of RNAs? To what extent do enzymes contribute to the temperature compensation of the reaction rates in mRNA turnover by lowering the energy barrier of the catalyzed reactions? We conclude with the ecological, forensic applications of the temperature-dependence of RNA degradation and the biotechnological aspects of mRNA vaccine production.
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30
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Geffroy B, Besson M, Sánchez-Baizán N, Clota F, Goikoetxea A, Sadoul B, Ruelle F, Blanc MO, Parrinello H, Hermet S, Blondeau-Bidet E, Pratlong M, Piferrer F, Vandeputte M, Allal F. Unraveling the genotype by environment interaction in a thermosensitive fish with a polygenic sex determination system. Proc Natl Acad Sci U S A 2021; 118:e2112660118. [PMID: 34880131 PMCID: PMC8685686 DOI: 10.1073/pnas.2112660118] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2021] [Indexed: 01/03/2023] Open
Abstract
In most animals, sex determination occurs at conception, when sex chromosomes are segregated following Mendelian laws. However, in multiple reptiles and fishes, this genetic sex can be overridden by external factors after fertilization or birth. In some species, the genetic sex may also be governed by multiple genes, further limiting our understanding of sex determination in such species. We used the European sea bass (Dicentrarchus labrax) as a model and combined genomic (using a single nucleotide polymorphism chip) and transcriptomic (RNA-Sequencing) approaches to thoroughly depict this polygenic sex determination system and its interaction with temperature. We estimated genetic sex tendency (eGST), defined as the estimated genetic liability to become a given sex under a liability threshold model for sex determination, which accurately predicts the future phenotypic sex. We found evidence that energetic pathways, concerning the regulation of lipids and glucose, are involved in sex determination and could explain why females tend to exhibit higher energy levels and improved growth compared to males. Besides, early exposure to high-temperature up-regulated sox3, followed by sox9a in individuals with intermediate eGST, but not in individuals showing highly female-biased eGST, providing the most parsimonious explanation for temperature-induced masculinization. This gonadal state was maintained likely by DNA methylation and the up-regulation of several genes involved in histone modifications, including jmjd1c Overall, we describe a sex determination system resulting from continuous genetic and environmental influences in an animal. Our results provide significant progress in our understanding of the mechanisms underlying temperature-induced masculinization in fish.
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Affiliation(s)
- Benjamin Geffroy
- MARBEC Université de Montpellier, CNRS, Ifremer, IRD, Palavas-les-Flots, France;
| | - Mathieu Besson
- SYSAAF, Station LPGP/INRAE, 35042 Rennes, France
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, 78350 Jouy-en-Josas, France
| | - Núria Sánchez-Baizán
- Institut de Ciències del Mar, Spanish National Research Council, Barcelona, Spain
| | - Frederic Clota
- MARBEC Université de Montpellier, CNRS, Ifremer, IRD, Palavas-les-Flots, France
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, 78350 Jouy-en-Josas, France
| | | | - Bastien Sadoul
- MARBEC Université de Montpellier, CNRS, Ifremer, IRD, Palavas-les-Flots, France
- ESE, Ecology and Ecosystem Health, Institut Agro, INRAE, Rennes, France
| | - François Ruelle
- Laboratoire Service d'Expérimentations Aquacoles, Ifremer, Palavas-les-Flots, France
| | - Marie-Odile Blanc
- Laboratoire Service d'Expérimentations Aquacoles, Ifremer, Palavas-les-Flots, France
| | - Hugues Parrinello
- MGX, BCM, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Sophie Hermet
- MARBEC Université de Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Eva Blondeau-Bidet
- MARBEC Université de Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Marine Pratlong
- MGX, BCM, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Francesc Piferrer
- Institut de Ciències del Mar, Spanish National Research Council, Barcelona, Spain
| | - Marc Vandeputte
- MARBEC Université de Montpellier, CNRS, Ifremer, IRD, Palavas-les-Flots, France
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, 78350 Jouy-en-Josas, France
| | - François Allal
- MARBEC Université de Montpellier, CNRS, Ifremer, IRD, Palavas-les-Flots, France
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31
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Whiteley S, McCuaig RD, Holleley CE, Rao S, Georges A. Dynamics of epigenetic modifiers and environmentally sensitive proteins in a reptile with temperature induced sex reversal. Biol Reprod 2021; 106:132-144. [PMID: 34849582 DOI: 10.1093/biolre/ioab217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/25/2021] [Indexed: 12/23/2022] Open
Abstract
The mechanisms by which sex is determined, and how a sexual phenotype is stably maintained during adulthood, has been the focus of vigorous scientific inquiry. Resources common to the biomedical field (automated staining and imaging platforms) were leveraged to provide the first immunofluorescent data for a reptile species with temperature induced sex reversal. Two four-plex immunofluorescent panels were explored across three sex classes (sex reversed ZZf females, normal ZWf females, and normal ZZm males). One panel was stained for chromatin remodelling genes JARID2 and KDM6B, and methylation marks H3K27me3, and H3K4me3 (Jumonji Panel). The other CaRe panel stained for environmental response genes CIRBP and RelA, and H3K27me3 and H3K4me3. Our study characterised tissue specific expression and cellular localisation patterns of these proteins and histone marks, providing new insights to the molecular characteristics of adult gonads in a dragon lizard Pogona vitticeps. The confirmation that mammalian antibodies cross react in P. vitticeps paves the way for experiments that can take advantage of this new immunohistochemical resource to gain a new understanding of the role of these proteins during embryonic development, and most importantly for P. vitticeps, the molecular underpinnings of sex reversal.
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Affiliation(s)
- Sarah Whiteley
- Institute for Applied Ecology, University of Canberra, Australia.,Australian National Wildlife Collection CSIRO National Research Collections Australia, Canberra, Australia
| | - Robert D McCuaig
- Gene Regulation and Translational Medicine Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Clare E Holleley
- Australian National Wildlife Collection CSIRO National Research Collections Australia, Canberra, Australia
| | - Sudha Rao
- Gene Regulation and Translational Medicine Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Australia
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32
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Sex Chromosomes and Master Sex-Determining Genes in Turtles and Other Reptiles. Genes (Basel) 2021; 12:genes12111822. [PMID: 34828428 PMCID: PMC8622242 DOI: 10.3390/genes12111822] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/12/2021] [Accepted: 11/16/2021] [Indexed: 11/24/2022] Open
Abstract
Among tetrapods, the well differentiated heteromorphic sex chromosomes of birds and mammals have been highly investigated and their master sex-determining (MSD) gene, Dmrt1 and SRY, respectively, have been identified. The homomorphic sex chromosomes of reptiles have been the least studied, but the gap with birds and mammals has begun to fill. This review describes our current knowledge of reptilian sex chromosomes at the cytogenetic and molecular level. Most of it arose recently from various studies comparing male to female gene content. This includes restriction site-associated DNA sequencing (RAD-Seq) experiments in several male and female samples, RNA sequencing and identification of Z- or X-linked genes by male/female comparative transcriptome coverage, and male/female transcriptomic or transcriptome/genome substraction approaches allowing the identification of Y- or W-linked transcripts. A few putative master sex-determining (MSD) genes have been proposed, but none has been demonstrated yet. Lastly, future directions in the field of reptilian sex chromosomes and their MSD gene studies are considered.
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33
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Tissue and Temperature-Specific RNA-Seq Analysis Reveals Genomic Versatility and Adaptive Potential in Wild Sea Turtle Hatchlings ( Caretta caretta). Animals (Basel) 2021; 11:ani11113013. [PMID: 34827746 PMCID: PMC8614379 DOI: 10.3390/ani11113013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/24/2021] [Accepted: 10/18/2021] [Indexed: 01/05/2023] Open
Abstract
Simple Summary Digital transcriptomics is rapidly emerging as a powerful new technology for modelling the environmental dynamics of the adaptive landscape in diverse lineages. This is particularly valuable in taxa such as turtles and tortoises (order Testudines) which contain a large fraction of endangered species at risk due to anthropogenic impacts on the environment, including pollution, overharvest, habitat degradation, and climate change. Sea turtles (family Cheloniidae) in particular invite a genomics-enabled approach to investigating their remarkable portfolio of adaptive evolution. Our de novo transcriptome assemblies and measurements of tissue- and temperature- specific global gene expression in the loggerhead sea turtle (Caretta caretta) reveal the genomic basis for potential resiliency in this endangered flagship species, and are crucial to future management and conservation strategies with attention to changing climates. We summarize the interactions among differentially expressed genes by producing network visualizations, and highlight the shared biological pathways related to development, migration, immunity, and longevity reported in the avian and reptilian literature. Our original results for loggerhead sea turtles provide a large, new comparative genomic resource for the investigation of genotype–phenotype relationships in amniotes. Abstract Background: Digital transcriptomics is rapidly emerging as a powerful new technology for modelling the environmental dynamics of the adaptive landscape in diverse lineages. This is particularly valuable in taxa such as turtles and tortoises (order Testudines) which contain a large fraction of endangered species at risk due to anthropogenic impacts on the environment, including pollution, overharvest, habitat degradation, and climate change. Sea turtles (family Cheloniidae) in particular invite a genomics-enabled approach to investigating their remarkable portfolio of adaptive evolution. The sex of the endangered loggerhead sea turtle (Caretta caretta) is subject to temperature-dependent sex determination (TSD), a mechanism by which exposure to temperatures during embryonic development irreversibly determines sex. Higher temperatures produce mainly female turtles and lower temperatures produce mainly male turtles. Incubation temperature can have long term effects on the immunity, migratory ability, and ultimately longevity of hatchlings. We perform RNA-seq differential expression analysis to investigate tissue- and temperature-specific gene expression within brain (n = 7) and gonadal (n = 4) tissue of male and female loggerhead hatchlings. Results: We assemble tissue- and temperature-specific transcriptomes and identify differentially expressed genes relevant to sexual development and life history traits of broad adaptive interest to turtles and other amniotic species. We summarize interactions among differentially expressed genes by producing network visualizations, and highlight shared biological pathways related to migration, immunity, and longevity reported in the avian and reptile literature. Conclusions: The measurement of tissue- and temperature-specific global gene expression of an endangered, flagship species such as the loggerhead sea turtle (Caretta caretta) reveals the genomic basis for potential resiliency and is crucial to future management and conservation strategies with attention to changing climates. Brain and gonadal tissue collected from experimentally reared loggerhead male and female hatchlings comprise an exceedingly rare dataset that permits the identification of genes enriched in functions related to sexual development, immunity, longevity, and migratory behavior and will serve as a large, new genomic resource for the investigation of genotype–phenotype relationships in amniotes.
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Lockley EC, Eizaguirre C. Effects of global warming on species with temperature-dependent sex determination: Bridging the gap between empirical research and management. Evol Appl 2021; 14:2361-2377. [PMID: 34745331 PMCID: PMC8549623 DOI: 10.1111/eva.13226] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/05/2021] [Accepted: 03/11/2021] [Indexed: 12/31/2022] Open
Abstract
Global warming could threaten over 400 species with temperature-dependent sex determination (TSD) worldwide, including all species of sea turtle. During embryonic development, rising temperatures might lead to the overproduction of one sex and, in turn, could bias populations' sex ratios to an extent that threatens their persistence. If climate change predictions are correct, and biased sex ratios reduce population viability, species with TSD may go rapidly extinct unless adaptive mechanisms, whether behavioural, physiological or molecular, exist to buffer these temperature-driven effects. Here, we summarize the discovery of the TSD phenomenon and its still elusive evolutionary significance. We then review the molecular pathways underpinning TSD in model species, along with the hormonal mechanisms that interact with temperatures to determine an individual's sex. To illustrate evolutionary mechanisms that can affect sex determination, we focus on sea turtle biology, discussing both the adaptive potential of this threatened TSD taxon, and the risks associated with conservation mismanagement.
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Affiliation(s)
- Emma C. Lockley
- School of Biological and Chemical SciencesQueen Mary University LondonLondonUK
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35
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Gómez-Redondo I, Planells B, Navarrete P, Gutiérrez-Adán A. Role of Alternative Splicing in Sex Determination in Vertebrates. Sex Dev 2021; 15:381-391. [PMID: 34583366 DOI: 10.1159/000519218] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/26/2021] [Indexed: 11/19/2022] Open
Abstract
During the process of sex determination, a germ-cell-containing undifferentiated gonad is converted into either a male or a female reproductive organ. Both the composition of sex chromosomes and the environment determine sex in vertebrates. It is assumed that transcription level regulation drives this cascade of mechanisms; however, transcription factors can alter gene expression beyond transcription initiation by controlling pre-mRNA splicing and thereby mRNA isoform production. Using the key time window in sex determination and gonad development in mice, it has been reported that new non-transcriptional events, such as alternative splicing, could play a key role in sex determination in mammals. We know the role of key regulatory factors, like WT1(+/-KTS) or FGFR2(b/c) in pre-mRNA splicing and sex determination, indicating that important steps in the vertebrate sex determination process probably operate at a post-transcriptional level. Here, we discuss the role of pre-mRNA splicing regulators in sex determination in vertebrates, focusing on the new RNA-seq data reported from mice fetal gonadal transcriptome.
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Affiliation(s)
| | - Benjamín Planells
- Departamento de Reproducción Animal, INIA, Madrid, Spain.,School of Biosciences, University of Nottingham, Nottingham, United Kingdom
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36
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Kratochvíl L, Stöck M, Rovatsos M, Bullejos M, Herpin A, Jeffries DL, Peichel CL, Perrin N, Valenzuela N, Pokorná MJ. Expanding the classical paradigm: what we have learnt from vertebrates about sex chromosome evolution. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200097. [PMID: 34304593 PMCID: PMC8310716 DOI: 10.1098/rstb.2020.0097] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2021] [Indexed: 12/15/2022] Open
Abstract
Until recently, the field of sex chromosome evolution has been dominated by the canonical unidirectional scenario, first developed by Muller in 1918. This model postulates that sex chromosomes emerge from autosomes by acquiring a sex-determining locus. Recombination reduction then expands outwards from this locus, to maintain its linkage with sexually antagonistic/advantageous alleles, resulting in Y or W degeneration and potentially culminating in their disappearance. Based mostly on empirical vertebrate research, we challenge and expand each conceptual step of this canonical model and present observations by numerous experts in two parts of a theme issue of Phil. Trans. R. Soc. B. We suggest that greater theoretical and empirical insights into the events at the origins of sex-determining genes (rewiring of the gonadal differentiation networks), and a better understanding of the evolutionary forces responsible for recombination suppression are required. Among others, crucial questions are: Why do sex chromosome differentiation rates and the evolution of gene dose regulatory mechanisms between male versus female heterogametic systems not follow earlier theory? Why do several lineages not have sex chromosomes? And: What are the consequences of the presence of (differentiated) sex chromosomes for individual fitness, evolvability, hybridization and diversification? We conclude that the classical scenario appears too reductionistic. Instead of being unidirectional, we show that sex chromosome evolution is more complex than previously anticipated and principally forms networks, interconnected to potentially endless outcomes with restarts, deletions and additions of new genomic material. This article is part of the theme issue 'Challenging the paradigm in sex chromosome evolution: empirical and theoretical insights with a focus on vertebrates (Part II)'.
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Affiliation(s)
- Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, Prague, Czech Republic
| | - Matthias Stöck
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries - IGB (Forschungsverbund Berlin), Müggelseedamm 301, 12587 Berlin, Germany
- Amphibian Research Center, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Michail Rovatsos
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, Prague, Czech Republic
| | - Mónica Bullejos
- Department of Experimental Biology, Faculty of Experimental Sciences, University of Jaén, Las Lagunillas Campus S/N, 23071 Jaén, Spain
| | - Amaury Herpin
- INRAE, LPGP, 35000 Rennes, France
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, People's Republic of China
| | - Daniel L. Jeffries
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Catherine L. Peichel
- Institute of Ecology and Evolution, University of Bern, CH-3012 Bern, Switzerland
| | - Nicolas Perrin
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Nicole Valenzuela
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Martina Johnson Pokorná
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, Prague, Czech Republic
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, Liběchov, Czech Republic
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37
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Kratochvíl L, Gamble T, Rovatsos M. Sex chromosome evolution among amniotes: is the origin of sex chromosomes non-random? Philos Trans R Soc Lond B Biol Sci 2021; 376:20200108. [PMID: 34304592 PMCID: PMC8310715 DOI: 10.1098/rstb.2020.0108] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2021] [Indexed: 12/29/2022] Open
Abstract
Sex chromosomes are a great example of a convergent evolution at the genomic level, having evolved dozens of times just within amniotes. An intriguing question is whether this repeated evolution was random, or whether some ancestral syntenic blocks have significantly higher chance to be co-opted for the role of sex chromosomes owing to their gene content related to gonad development. Here, we summarize current knowledge on the evolutionary history of sex determination and sex chromosomes in amniotes and evaluate the hypothesis of non-random emergence of sex chromosomes. The current data on the origin of sex chromosomes in amniotes suggest that their evolution is indeed non-random. However, this non-random pattern is not very strong, and many syntenic blocks representing putatively independently evolved sex chromosomes are unique. Still, repeatedly co-opted chromosomes are an excellent model system, as independent co-option of the same genomic region for the role of sex chromosome offers a great opportunity for testing evolutionary scenarios on the sex chromosome evolution under the explicit control for the genomic background and gene identity. Future studies should use these systems more to explore the convergent/divergent evolution of sex chromosomes. This article is part of the theme issue 'Challenging the paradigm in sex chromosome evolution: empirical and theoretical insights with a focus on vertebrates (Part II)'.
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Affiliation(s)
- Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, Prague, Czech Republic
| | - Tony Gamble
- Department of Biological Sciences, Marquette University, Milwaukee, WI, USA
- Bell Museum of Natural History, University of Minnesota, Saint Paul, MN, USA
- Milwaukee Public Museum, Milwaukee, WI, USA
| | - Michail Rovatsos
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, Prague, Czech Republic
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38
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Stöck M, Kratochvíl L, Kuhl H, Rovatsos M, Evans BJ, Suh A, Valenzuela N, Veyrunes F, Zhou Q, Gamble T, Capel B, Schartl M, Guiguen Y. A brief review of vertebrate sex evolution with a pledge for integrative research: towards ' sexomics'. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200426. [PMID: 34247497 PMCID: PMC8293304 DOI: 10.1098/rstb.2020.0426] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/08/2021] [Indexed: 02/07/2023] Open
Abstract
Triggers and biological processes controlling male or female gonadal differentiation vary in vertebrates, with sex determination (SD) governed by environmental factors or simple to complex genetic mechanisms that evolved repeatedly and independently in various groups. Here, we review sex evolution across major clades of vertebrates with information on SD, sexual development and reproductive modes. We offer an up-to-date review of divergence times, species diversity, genomic resources, genome size, occurrence and nature of polyploids, SD systems, sex chromosomes, SD genes, dosage compensation and sex-biased gene expression. Advances in sequencing technologies now enable us to study the evolution of SD at broader evolutionary scales, and we now hope to pursue a sexomics integrative research initiative across vertebrates. The vertebrate sexome comprises interdisciplinary and integrated information on sexual differentiation, development and reproduction at all biological levels, from genomes, transcriptomes and proteomes, to the organs involved in sexual and sex-specific processes, including gonads, secondary sex organs and those with transcriptional sex-bias. The sexome also includes ontogenetic and behavioural aspects of sexual differentiation, including malfunction and impairment of SD, sexual differentiation and fertility. Starting from data generated by high-throughput approaches, we encourage others to contribute expertise to building understanding of the sexomes of many key vertebrate species. This article is part of the theme issue 'Challenging the paradigm in sex chromosome evolution: empirical and theoretical insights with a focus on vertebrates (Part I)'.
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Affiliation(s)
- Matthias Stöck
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries—IGB (Forschungsverbund Berlin), Müggelseedamm 301, 12587 Berlin, Germany
- Amphibian Research Center, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 12844 Prague, Czech Republic
| | - Heiner Kuhl
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries—IGB (Forschungsverbund Berlin), Müggelseedamm 301, 12587 Berlin, Germany
| | - Michail Rovatsos
- Amphibian Research Center, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Ben J. Evans
- Department of Biology, McMaster University, Life Sciences Building Room 328, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
| | - Alexander Suh
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TU, UK
- Department of Organismal Biology—Systematic Biology, Evolutionary Biology Centre, Science for Life Laboratory, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
| | - Nicole Valenzuela
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Frédéric Veyrunes
- Institut des Sciences de l'Evolution de Montpellier, ISEM UMR 5554 (CNRS/Université de Montpellier/IRD/EPHE), Montpellier, France
| | - Qi Zhou
- MOE Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
- Department of Neuroscience and Developmental Biology, University of Vienna, A-1090 Vienna, Austria
| | - Tony Gamble
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, USA
| | - Blanche Capel
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Manfred Schartl
- Developmental Biochemistry, Biocenter, University of Würzburg, 97074 Würzburg, Germany
- The Xiphophorus Genetic Stock Center, Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
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39
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Mezzasalma M, Guarino FM, Odierna G. Lizards as Model Organisms of Sex Chromosome Evolution: What We Really Know from a Systematic Distribution of Available Data? Genes (Basel) 2021; 12:1341. [PMID: 34573323 PMCID: PMC8468487 DOI: 10.3390/genes12091341] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/20/2021] [Accepted: 08/27/2021] [Indexed: 01/19/2023] Open
Abstract
Lizards represent unique model organisms in the study of sex determination and sex chromosome evolution. Among tetrapods, they are characterized by an unparalleled diversity of sex determination systems, including temperature-dependent sex determination (TSD) and genetic sex determination (GSD) under either male or female heterogamety. Sex chromosome systems are also extremely variable in lizards. They include simple (XY and ZW) and multiple (X1X2Y and Z1Z2W) sex chromosome systems and encompass all the different hypothesized stages of diversification of heterogametic chromosomes, from homomorphic to heteromorphic and completely heterochromatic sex chromosomes. The co-occurrence of TSD, GSD and different sex chromosome systems also characterizes different lizard taxa, which represent ideal models to study the emergence and the evolutionary drivers of sex reversal and sex chromosome turnover. In this review, we present a synthesis of general genome and karyotype features of non-snakes squamates and discuss the main theories and evidences on the evolution and diversification of their different sex determination and sex chromosome systems. We here provide a systematic assessment of the available data on lizard sex chromosome systems and an overview of the main cytogenetic and molecular methods used for their identification, using a qualitative and quantitative approach.
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Affiliation(s)
- Marcello Mezzasalma
- Department of Biology, University of Naples Federico II, I-80126 Naples, Italy; (F.M.G.); (G.O.)
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Universidade do Porto, Rua Padre Armando Quintas 7, 4485-661 Vairaõ, Portugal
| | - Fabio M. Guarino
- Department of Biology, University of Naples Federico II, I-80126 Naples, Italy; (F.M.G.); (G.O.)
| | - Gaetano Odierna
- Department of Biology, University of Naples Federico II, I-80126 Naples, Italy; (F.M.G.); (G.O.)
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40
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Renn SC, Hurd PL. Epigenetic Regulation and Environmental Sex Determination in Cichlid Fishes. Sex Dev 2021; 15:93-107. [PMID: 34433170 PMCID: PMC8440468 DOI: 10.1159/000517197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 05/12/2021] [Indexed: 12/14/2022] Open
Abstract
Studying environmental sex determination (ESD) in cichlids provides a phylogenetic and comparative approach to understand the evolution of the underlying mechanisms, their impact on the evolution of the overlying systems, and the neuroethology of life history strategies. Natural selection normally favors parents who invest equally in the development of male and female offspring, but evolution may favor deviations from this 50:50 ratio when environmental conditions produce an advantage for doing so. Many species of cichlids demonstrate ESD in response to water chemistry (temperature, pH, and oxygen concentration). The relative strengths of and the exact interactions between these factors vary between congeners, demonstrating genetic variation in sensitivity. The presence of sizable proportions of the less common sex towards the environmental extremes in most species strongly suggests the presence of some genetic sex-determining loci acting in parallel with the ESD factors. Sex determination and differentiation in these species does not seem to result in the organization of a final and irreversible sexual fate, so much as a life-long ongoing battle between competing male- and female-determining genetic and hormonal networks governed by epigenetic factors. We discuss what is and is not known about the epigenetic mechanism behind the differentiation of both gonads and sex differences in the brain. Beyond the well-studied tilapia species, the 2 best-studied dwarf cichlid systems showing ESD are the South American genus Apistogramma and the West African genus Pelvicachromis. Both species demonstrate male morphs with alternative reproductive tactics. We discuss the further neuroethology opportunities such systems provide to the study of epigenetics of alternative life history strategies and other behavioral variation.
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Affiliation(s)
| | - Peter L Hurd
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, CA
- Department of Psychology, University of Alberta, Edmonton, AB, CA
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41
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Weber C, Capel B. Sex determination without sex chromosomes. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200109. [PMID: 34247500 DOI: 10.1098/rstb.2020.0109] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
With or without sex chromosomes, sex determination is a synthesis of many molecular events that drives a community of cells towards a coordinated tissue fate. In this review, we will consider how a sex determination pathway can be engaged and stabilized without an inherited genetic determinant. In many reptilian species, no sex chromosomes have been identified, yet a conserved network of gene expression is initiated. Recent studies propose that epigenetic regulation mediates the effects of temperature on these genes through dynamic post-transcriptional, post-translational and metabolic pathways. It is likely that there is no singular regulator of sex determination, but rather an accumulation of molecular events that shift the scales towards one fate over another until a threshold is reached sufficient to maintain and stabilize one pathway and repress the alternative pathway. Investigations into the mechanism underlying sex determination without sex chromosomes should focus on cellular processes that are frequently activated by multiple stimuli or can synthesize multiple inputs and drive a coordinated response. This article is part of the theme issue 'Challenging the paradigm in sex chromosome evolution: empirical and theoretical insights with a focus on vertebrates (Part I)'.
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Affiliation(s)
- Ceri Weber
- Department of Cell Biology, Duke University Medical Center, 456 Nanaline Duke, 307 Research Drive, Durham, NC 27710, USA
| | - Blanche Capel
- Department of Cell Biology, Duke University Medical Center, 456 Nanaline Duke, 307 Research Drive, Durham, NC 27710, USA
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42
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Teng J, Zhao Y, Chen HJ, Xue LY, Ji XS. Global expression response of genes in sex-undifferentiated Nile tilapia gonads after exposure to trace letrozole. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 217:112255. [PMID: 33915448 DOI: 10.1016/j.ecoenv.2021.112255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 04/06/2021] [Accepted: 04/12/2021] [Indexed: 06/12/2023]
Abstract
The aromatase inhibitor letrozole can be found in rivers, effluents, and even drinking water. Studies have demonstrated that letrozole affects various metabolic pathways and may cause reproductive toxicity, especially in fish exposed during development. However, studies on the effect of a low concentration of letrozole at the whole-gonad transcriptomic level in the early stage of fish sexual development have not been investigated. The aim of our study was to explore the potential effects of a low concentration of letrozole on the gonad transcriptome of Nile tilapia at an early stage of sexual development. In this study, 9 dpf (days postfertilization) Nile tilapia were exposed to trace letrozole for 12 days. Letrozole exposure from 9 dpf to 21 dpf persistently altered phenotypic sex development and induced the male-biased sex ratio. The transcriptome results showed that 1173 differentially expressed genes (DEGs) were present in the female control vs 1.5 μg/L letrozole-treated female comparison group and that 1576 DEGs were present in the 1.5 μg/L letrozole-treated female vs male control comparison group. Differentially expressed gene enrichment analysis revealed several crucial pathways, including the drug metabolism-cytochrome P450 pathway, the ErbB-PI3K/Akt/mTOR pathway, and the calcium signalling pathway. Further analysis of these identified DEGs indicated that some key genes correlated with metabolism and epigenetic regulation were significantly affected by letrozole, such as UDP-glucuronosyltransferase (Ugt), glutathione S-transferase omega-1 (Gsto1), lysine-specific demethylase 6bb (Kdm6bb, original name is Kdm6a), jumonji and AT-rich interaction domain containing 2 (Jarid2b, original name is Jarid2), growth arrest and DNA damage inducible gamma (Gadd45g), and chromobox protein 7 (Cbx7). The qRT-PCR validation results for twelve DEGs showed that the Pearson's correlation of the log10fold change values between the qPCR and RNA-Seq results was 0.90, indicating the accuracy and reliability of the RNA-Seq results. Our study is the first to report the effect of letrozole on the transcriptome of gonads from fish during early-stage sexual development. These findings will be useful for understanding the toxic effects and molecular mechanisms of letrozole exposure at the early stage of gonad development on the sexual development of aquatic organisms.
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Affiliation(s)
- Jian Teng
- College of Marine Sciences, Ningbo University, Ningbo, Zhejiang, China; College of Animal Science and Technology, Shandong Agricultural University, Taian, Shandong, China
| | - Yan Zhao
- College of Animal Science and Technology, Shandong Agricultural University, Taian, Shandong, China
| | - Hong Ju Chen
- College of Animal Science and Technology, Shandong Agricultural University, Taian, Shandong, China
| | - Liang Yi Xue
- College of Marine Sciences, Ningbo University, Ningbo, Zhejiang, China.
| | - Xiang Shan Ji
- College of Animal Science and Technology, Shandong Agricultural University, Taian, Shandong, China.
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43
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Merchant-Larios H, Díaz-Hernández V, Cortez D. Molecular and Cellular Mechanisms Underlying Temperature-Dependent Sex Determination in Turtles. Sex Dev 2021; 15:38-46. [PMID: 34167126 DOI: 10.1159/000515296] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 02/16/2021] [Indexed: 11/19/2022] Open
Abstract
The discovery in mammals that fetal testes are required in order to develop the male phenotype inspired research efforts to elucidate the mechanisms underlying gonadal sex determination and differentiation in vertebrates. A pioneer work in 1966 that demonstrated the influence of incubation temperature on sexual phenotype in some reptilian species triggered great interest in the environment's role as a modulator of plasticity in sex determination. Several chelonian species have been used as animal models to test hypotheses concerning the mechanisms involved in temperature-dependent sex determination (TSD). This brief review intends to outline the history of scientific efforts that corroborate our current understanding of the state-of-the-art in TSD using chelonian species as a reference.
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Affiliation(s)
- Horacio Merchant-Larios
- Instituto de Investigaciones Biomédicas, Departamento de Biología Celular y Fisiología, Universidad Nacional Autónoma de México, Mexico city, Mexico
| | - Verónica Díaz-Hernández
- Facultad de Medicina, Departamento de Embriología, Universidad Nacional Autónoma de México, Mexico city, Mexico
| | - Diego Cortez
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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44
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Schwanz LE, Georges A. Sexual Development and the Environment: Conclusions from 40 Years of Theory. Sex Dev 2021; 15:7-22. [PMID: 34130303 DOI: 10.1159/000515221] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/29/2021] [Indexed: 11/19/2022] Open
Abstract
In this review, we consider the insight that has been gained through theoretical examination of environmental sex determination (ESD) and thermolability - how theory has progressed our understanding of the ecological and evolutionary dynamics associated with ESD, the transitional pathways between different modes of sex determination, and the underlying mechanisms. Following decades of theory on the adaptive benefits of ESD, several hypotheses seem promising. These hypotheses focus on the importance of differential fitness (sex-specific effects of temperature on fitness) in generating selection for ESD, but highlight alternative ways differential fitness arises: seasonal impacts on growth, sex-specific ages of maturation, and sex-biased dispersal. ESD has the potential to generate biased sex ratios quite easily, leading to complex feedbacks between the ecology and evolution of ESD. Frequency-dependent selection on sex acts on ESD-related traits, driving local adaptation or plasticity to restore equilibrium sex ratio. However, migration and overlapping generations ("mixing") diminish local adaptation and leave each cohort/population with the potential for biased sex ratios. Incorporating mechanism into ecology and evolution models reveals similarities between different sex-determining systems. Dosage and gene regulatory network models of sexual development are beginning to shed light on how temperature sensitivity and thresholds may arise. The unavoidable temperature sensitivity in sex-determining systems inherent to these models suggests that evolutionary transitions between genotypic sex determination (GSD) and temperature-dependent sex determination, and between different forms of GSD, are simple and elegant. Theoretical models are often best-served by considering a single piece of a puzzle; however, there is much to gain from reflecting on all of the pieces together in one integrative picture.
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Affiliation(s)
- Lisa E Schwanz
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia
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45
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Whiteley SL, Castelli MA, Dissanayake DSB, Holleley CE, Georges A. Temperature-Induced Sex Reversal in Reptiles: Prevalence, Discovery, and Evolutionary Implications. Sex Dev 2021; 15:148-156. [PMID: 34111872 DOI: 10.1159/000515687] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 03/05/2021] [Indexed: 11/19/2022] Open
Abstract
Sex reversal is the process by which an individual develops a phenotypic sex that is discordant with its chromosomal or genotypic sex. It occurs in many lineages of ectothermic vertebrates, such as fish, amphibians, and at least one agamid and one scincid reptile species. Sex reversal is usually triggered by an environmental cue that alters the genetically determined process of sexual differentiation, but it can also be caused by exposure to exogenous chemicals, hormones, or pollutants. Despite the occurrence of both temperature-dependent sex determination (TSD) and genetic sex determination (GSD) broadly among reptiles, only 2 species of squamates have thus far been demonstrated to possess sex reversal in nature (GSD with overriding thermal influence). The lack of species with unambiguously identified sex reversal is not necessarily a reflection of a low incidence of this trait among reptiles. Indeed, sex reversal may be relatively common in reptiles, but little is known of its prevalence, the mechanisms by which it occurs, or the consequences of sex reversal for species in the wild under a changing climate. In this review, we present a roadmap to the discovery of sex reversal in reptiles, outlining the various techniques that allow new occurrences of sex reversal to be identified, the molecular mechanisms that may be involved in sex reversal and how to identify them, and approaches for assessing the impacts of sex reversal in wild populations. We discuss the evolutionary implications of sex reversal and use the central bearded dragon (Pogona vitticeps) and the eastern three-lined skink (Bassiana duperreyi) as examples of how species with opposing patterns of sex reversal may be impacted differently by our rapidly changing climate. Ultimately, this review serves to highlight the importance of understanding sex reversal both in the laboratory and in wild populations and proposes practical solutions to foster future research.
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Affiliation(s)
- Sarah L Whiteley
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia.,Australian National Wildlife Collection, CSIRO, Canberra, Australian Capital Territory, Australia
| | - Meghan A Castelli
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia.,Australian National Wildlife Collection, CSIRO, Canberra, Australian Capital Territory, Australia
| | - Duminda S B Dissanayake
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia.,Australian National Wildlife Collection, CSIRO, Canberra, Australian Capital Territory, Australia
| | - Clare E Holleley
- Australian National Wildlife Collection, CSIRO, Canberra, Australian Capital Territory, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia
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46
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Marroquín-Flores RA, Bowden RM, Paitz RT. Brief exposure to warm temperatures reduces intron retention in Kdm6b in a species with temperature-dependent sex determination. Biol Lett 2021; 17:20210167. [PMID: 34102073 PMCID: PMC8187015 DOI: 10.1098/rsbl.2021.0167] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/13/2021] [Indexed: 12/14/2022] Open
Abstract
Animals with temperature-dependent sex determination (TSD) respond to thermal cues during early embryonic development to trigger gonadal differentiation. TSD has primarily been studied using constant temperature incubations, where embryos are exposed to constant male- or female-producing temperatures, and these studies have identified genes that display sex-specific expression in response to incubation temperature. Kdm6b, a histone demethylase gene, has received specific attention as it is among the initial genes to respond to incubation temperature and is necessary for testis development. Interestingly, Kdm6b retains an intron when eggs are incubated at a constant male-producing temperature, but the role of thermal variability in this developmental process is relatively understudied. Species with TSD regularly experience thermal cues that fluctuate between male- and female-producing temperatures throughout development but it is unclear how Kdm6b responds to such variable temperatures. In this study, we investigate temperature-sensitive splicing in Kdm6b by exposing embryos to male- and female-producing thermal conditions. We show a rapid decrease in levels of the intron retaining transcript of Kdm6b upon exposure to female-producing conditions. These results demonstrate that, under ecologically relevant conditions, temperature-sensitive splicing can differentially regulate genes critical to TSD.
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Affiliation(s)
| | - Rachel M. Bowden
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Ryan T. Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
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47
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Ruiz-García A, Roco ÁS, Bullejos M. Sex Differentiation in Amphibians: Effect of Temperature and Its Influence on Sex Reversal. Sex Dev 2021; 15:157-167. [PMID: 34000727 DOI: 10.1159/000515220] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 12/20/2020] [Indexed: 11/19/2022] Open
Abstract
The role of environmental factors in sexual differentiation in amphibians is not new. The effect of hormones or hormone-like compounds is widely demonstrated. However, the effect of temperature has traditionally been regarded as something anecdotal that occurs in extreme situations and not as a factor to be considered. The data currently available reveal a different situation. Sexual differentiation in some amphibian species can be altered even by small changes in temperature. On the other hand, although not proven, it is possible that temperature is related to the appearance of sex-reversed individuals in natural populations under conditions unrelated to environmental contaminants. According to this, temperature, through sex reversal (phenotypic sex opposed to genetic sex), could play an important role in the turnover of sex-determining genes and in the maintenance of homomorphic sex chromosomes in this group. Accordingly, and given the expected increase in global temperatures, growth and sexual differentiation in amphibians could easily be affected, altering the sex ratio in natural populations and posing major conservation challenges for a group in worldwide decline. It is therefore particularly urgent to understand the mechanism by which temperature affects sexual differentiation in amphibians.
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Affiliation(s)
- Adrián Ruiz-García
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Jaén, Spain
| | - Álvaro S Roco
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Jaén, Spain
| | - Mónica Bullejos
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Jaén, Spain
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48
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Piferrer F, Anastasiadi D. Do the Offspring of Sex Reversals Have Higher Sensitivity to Environmental Perturbations? Sex Dev 2021; 15:134-147. [PMID: 33910195 DOI: 10.1159/000515192] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 12/04/2020] [Indexed: 11/19/2022] Open
Abstract
Sex determination systems in vertebrates vary along a continuum from genetic (GSD) to environmental sex determination (ESD). Individuals that show a sexual phenotype opposite to their genotypic sex are called sex reversals. Aside from genetic elements, temperature, sex steroids, and exogenous chemicals are common factors triggering sex reversal, a phenomenon that may occur even in strict GSD species. In this paper, we review the literature on instances of sex reversal in fish, amphibians, reptiles, birds, and mammals. We focus on the offspring of sex-reversed parents in the instances that they can be produced, and show that in all cases studied the offspring of these sex-reversed parents exhibit a higher sensitivity to environmental perturbations than the offspring of non-sex-reversed parents. We suggest that the inheritance of this sensitivity, aside from possible genetic factors, is likely to be mediated by epigenetic mechanisms such as DNA methylation, since these mechanisms are responsive to environmental cues, and epigenetic modifications can be transmitted to the subsequent generations. Species with a chromosomal GSD system with environmental sensitivity and availability of genetic sex markers should be employed to further test whether offspring of sex-reversed parents have greater sensitivity to environmental perturbations. Future studies could also benefit from detailed whole-genome data in order to elucidate the underlying molecular mechanisms. Finally, we discuss the consequences of such higher sensitivity in the context of global climate change.
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Affiliation(s)
- Francesc Piferrer
- Institut de Ciències del Mar (ICM), Spanish National Research Council (CSIC), Barcelona, Spain
| | - Dafni Anastasiadi
- The New Zealand Institute for Plant and Food Research Limited, Nelson, New Zealand
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49
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Bowden RM, Paitz RT. Is Thermal Responsiveness Affected by Maternal Estrogens in Species with Temperature-Dependent Sex Determination? Sex Dev 2021; 15:69-79. [PMID: 33902053 DOI: 10.1159/000515187] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/17/2021] [Indexed: 11/19/2022] Open
Abstract
In species with temperature-dependent sex determination (TSD), incubation temperatures regulate the expression of genes involved in gonadal differentiation and determine whether the gonads develop into ovaries or testes. For most species, natural incubation conditions result in transient exposure to thermal cues for both ovarian and testis development, but how individuals respond to this transient exposure varies and can drive variation in the resulting sex ratios. Here, we argue that variation in the timing to respond to temperature cues, or thermal responsiveness, is a trait needing further study. Recent work in the red-eared slider turtle (Trachemys scripta) has found that when embryos experience transient exposure to warm conditions (i.e., heatwaves), some embryos show high responsiveness, requiring only short exposures to commit to ovarian development, while others show low responsiveness, developing testes even after more extended exposures to warm conditions. We discuss how maternal estrogens might influence thermal responsiveness for organisms that develop under thermal fluctuations. Examining the interplay of molecular responses to more subtle thermal and endocrine environments may reveal significant insights into the process of sex determination in species with TSD.
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Affiliation(s)
- Rachel M Bowden
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
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50
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Sánchez JM, Gómez-Redondo I, Browne JA, Planells B, Gutiérrez-Adán A, Lonergan P. MicroRNAs in amniotic fluid and maternal blood plasma associated with sex determination and early gonad differentiation in cattle†. Biol Reprod 2021; 105:345-358. [PMID: 33889937 PMCID: PMC8335352 DOI: 10.1093/biolre/ioab079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/22/2021] [Accepted: 04/12/2021] [Indexed: 12/19/2022] Open
Abstract
We hypothesized that sexually dimorphic differences exist in the expression of miRNAs in amniotic fluid (AF) and maternal blood plasma (MP) in association with the process of sex determination and gonad differentiation in cattle. Amniotic fluid and MP were collected from six pregnant heifers (three carrying a single male and three a single female embryo) following slaughter on Day 39 postinsemination, coinciding with the peak of SRY expression. Samples (six AF and six MP) were profiled using an miRNA Serum/Plasma Focus PCR Panel. Differentially expressed (DE) miRNAs were identified in AF (n = 5) and associated MP (n = 56) of male vs. female embryos (P < 0.05). Functional analysis showed that inflammatory and immune response were among the 13 biological processes enriched by miRNAs DE in MP in the male group (FDR < 0.05), suggesting that these sex-dependent DE miRNAs may be implicated in modulating the receptivity of the dam to a male embryo. Further, we compared the downstream targets of the sex-dependent DE miRNAs detected in MP with genes previously identified as DE in male vs. female genital ridges. The analyses revealed potential targets that might be important during this developmental stage such as SHROOM2, DDX3Y, SOX9, SRY, PPP1CB, JARID2, USP9X, KDM6A, and EIF2S3. Results from this study highlight novel aspects of sex determination and embryo–maternal communication in cattle such as the potential role of miRNAs in gonad development as well as in the modulation of the receptivity of the dam to a male embryo.
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Affiliation(s)
- José María Sánchez
- Animal and Crops Sciences, School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.,Departamento de Reproducción Animal, INIA, Madrid, Spain
| | | | - John A Browne
- Animal and Crops Sciences, School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland
| | | | | | - Pat Lonergan
- Animal and Crops Sciences, School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland
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