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Liu M, Ding H, Jin C, Wang M, Li P, Bao Z, Wang B, Hu J. Theoretical Analysis and Expression Profiling of 17β-Hydroxysteroid Dehydrogenase Genes in Gonadal Development and Steroidogenesis of Leopard Coral Grouper ( Plectropomus leopardus). Int J Mol Sci 2024; 25:2180. [PMID: 38396857 PMCID: PMC10889806 DOI: 10.3390/ijms25042180] [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: 12/22/2023] [Revised: 01/29/2024] [Accepted: 02/03/2024] [Indexed: 02/25/2024] Open
Abstract
The differentiation and developmental trajectory of fish gonads, significantly important for fish breeding, culture, and production, has long been a focal point in the fields of fish genetics and developmental biology. However, the mechanism of gonadal differentiation in leopard coral grouper (Plectropomus leopardus) remains unclear. This study investigates the 17β-Hydroxysteroid Dehydrogenase (Hsd17b) gene family in P. leopardus, with a focus on gene characterization, expression profiling, and functional analysis. The results reveal that the P. leopardus's Hsd17b gene family comprises 11 members, all belonging to the SDR superfamily. The amino acid similarity is only 12.96%, but conserved motifs, such as TGxxxGxG and S-Y-K, are present in these genes. Hsd17b12a and Hsd17b12b are unique homologs in fish, and chromosomal localization has confirmed that they are not derived from different transcripts of the same gene, but rather are two independent genes. The Hsd17b family genes, predominantly expressed in the liver, heart, gills, kidneys, and gonads, are involved in synthesizing or metabolizing sex steroid hormones and neurotransmitters, with their expression patterns during gonadal development categorized into three distinct categories. Notably, Hsd17b4 and Hsd17b12a were highly expressed in the testis and ovary, respectively, suggesting their involvement in the development of reproductive cells in these organs. Fluorescence in situ hybridization (FISH) further indicated specific expression sites for these genes, with Hsd17b4 primarily expressed in germ stem cells and Hsd17b12a in oocytes. This comprehensive study provides foundational insights into the role of the Hsd17b gene family in gonadal development and steroidogenesis in P. leopardus, contributing to the broader understanding of fish reproductive biology and aquaculture breeding.
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Affiliation(s)
- Mingjian Liu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.L.); (H.D.); (C.J.); (M.W.); (P.L.); (Z.B.)
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya 572025, China
| | - Hui Ding
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.L.); (H.D.); (C.J.); (M.W.); (P.L.); (Z.B.)
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya 572025, China
| | - Chaofan Jin
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.L.); (H.D.); (C.J.); (M.W.); (P.L.); (Z.B.)
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya 572025, China
| | - Mingyi Wang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.L.); (H.D.); (C.J.); (M.W.); (P.L.); (Z.B.)
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya 572025, China
| | - Peiyu Li
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.L.); (H.D.); (C.J.); (M.W.); (P.L.); (Z.B.)
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya 572025, China
| | - Zhenmin Bao
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.L.); (H.D.); (C.J.); (M.W.); (P.L.); (Z.B.)
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya 572025, China
- Hainan Seed Industry Laboratory, Sanya 572025, China
- Southern Marine Science and Engineer Guangdong Laboratory, Guangzhou 511458, China
| | - Bo Wang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.L.); (H.D.); (C.J.); (M.W.); (P.L.); (Z.B.)
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya 572025, China
- Hainan Seed Industry Laboratory, Sanya 572025, China
| | - Jingjie Hu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.L.); (H.D.); (C.J.); (M.W.); (P.L.); (Z.B.)
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya 572025, China
- Hainan Seed Industry Laboratory, Sanya 572025, China
- Southern Marine Science and Engineer Guangdong Laboratory, Guangzhou 511458, China
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Smiley KO, Munley KM, Aghi K, Lipshutz SE, Patton TM, Pradhan DS, Solomon-Lane TK, Sun SED. Sex diversity in the 21st century: Concepts, frameworks, and approaches for the future of neuroendocrinology. Horm Behav 2024; 157:105445. [PMID: 37979209 PMCID: PMC10842816 DOI: 10.1016/j.yhbeh.2023.105445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/11/2023] [Accepted: 10/18/2023] [Indexed: 11/20/2023]
Abstract
Sex is ubiquitous and variable throughout the animal kingdom. Historically, scientists have used reductionist methodologies that rely on a priori sex categorizations, in which two discrete sexes are inextricably linked with gamete type. However, this binarized operationalization does not adequately reflect the diversity of sex observed in nature. This is due, in part, to the fact that sex exists across many levels of biological analysis, including genetic, molecular, cellular, morphological, behavioral, and population levels. Furthermore, the biological mechanisms governing sex are embedded in complex networks that dynamically interact with other systems. To produce the most accurate and scientifically rigorous work examining sex in neuroendocrinology and to capture the full range of sex variability and diversity present in animal systems, we must critically assess the frameworks, experimental designs, and analytical methods used in our research. In this perspective piece, we first propose a new conceptual framework to guide the integrative study of sex. Then, we provide practical guidance on research approaches for studying sex-associated variables, including factors to consider in study design, selection of model organisms, experimental methodologies, and statistical analyses. We invite fellow scientists to conscientiously apply these modernized approaches to advance our biological understanding of sex and to encourage academically and socially responsible outcomes of our work. By expanding our conceptual frameworks and methodological approaches to the study of sex, we will gain insight into the unique ways that sex exists across levels of biological organization to produce the vast array of variability and diversity observed in nature.
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Affiliation(s)
- Kristina O Smiley
- Department of Psychological and Brain Sciences, University of Massachusetts Amherst, 639 North Pleasant Street, Morrill IVN Neuroscience, Amherst, MA 01003, USA.
| | - Kathleen M Munley
- Department of Psychology, University of Houston, 3695 Cullen Boulevard, Houston, TX 77204, USA.
| | - Krisha Aghi
- Department of Integrative Biology and Physiology, University of California Los Angeles, 405 Hilgard Ave, Los Angeles, CA 90095, USA.
| | - Sara E Lipshutz
- Department of Biology, Duke University, 130 Science Drive, Durham, NC 27708, USA.
| | - Tessa M Patton
- Bioinformatics Program, Loyola University Chicago, 1032 West Sheridan Road, LSB 317, Chicago, IL 60660, USA.
| | - Devaleena S Pradhan
- Department of Biological Sciences, Idaho State University, 921 South 8th Avenue, Mail Stop 8007, Pocatello, ID 83209, USA.
| | - Tessa K Solomon-Lane
- Scripps, Pitzer, Claremont McKenna Colleges, 925 North Mills Avenue, Claremont, CA 91711, USA.
| | - Simón E D Sun
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.
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Yao A, Nakamura M, Kohtsuka H, Sunobe T, Miura T. Gonadal and cellular dynamics during protogynous sex change in the harlequin sandsmelt Parapercis pulchella. JOURNAL OF FISH BIOLOGY 2023; 103:1347-1356. [PMID: 37621220 DOI: 10.1111/jfb.15534] [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: 04/10/2023] [Revised: 07/19/2023] [Accepted: 08/23/2023] [Indexed: 08/26/2023]
Abstract
Some teleost fishes change their sex, and some of these fishes have specific gonads known as "ovotestes," that is, gonads containing both ovarian and testicular tissues. In this study, we revealed the gonadal transformation process and cell dynamics during the female-to-male sex change in the harlequin sandsmelt, Parapercis pulchella (Pinguipetidae), in which females possess ovotestes. Histological observations revealed that although female ovotestes were composed of oocytes, a few cysts of male germ cells were observed among them. At the initial phase of sex change, male germ cells increased, and spermatogenesis proceeded. After that, oocytes decreased and finally disappeared, and the gonads became functional testes. Immunohistochemistry using antibodies against Pcna (proliferating cell nuclear antigen) as a cell proliferation marker revealed that spermatogonia were Pcna positive, whereas spermatocytes were negative, in female ovotestes. This suggests that spermatogenesis is arrested at the spermatocyte stage. In addition, some somatic cells surrounding oocytes, which were thought to be the female follicle cells, were Pcna positive during sex change, indicating that these cells proliferate during sex change and are reused in male testes after sex change. Also, immunostaining using antibodies against active cleaved-Caspase3a as an apoptosis marker demonstrated that oocytes degenerated through apoptotic cell death at the late transition stage. Together with previous findings in other fishes, these findings suggested that the histological processes in gonads during sex change, such as the order of developmental events, developmental fates of ovarian cavities, and ovotestis structures, are diversified among fish species. In contrast, cellular dynamics of female germ and somatic cells during sex change are common among protogynous species.
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Affiliation(s)
- Akifumi Yao
- Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Japan
| | - Mayuko Nakamura
- Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Japan
| | - Hisanori Kohtsuka
- Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Japan
| | - Tomoki Sunobe
- Laboratory of Fish Behavioral Ecology, Tateyama Station, Field Science Center, Tokyo University of Marine Science and Technology, Tateyama, Japan
| | - Toru Miura
- Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Japan
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Chen KH, Pannell JR. Unisexual flowers as a resolution to intralocus sexual conflict in hermaphrodites. Proc Biol Sci 2023; 290:20232137. [PMID: 38018108 PMCID: PMC10685137 DOI: 10.1098/rspb.2023.2137] [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: 09/19/2023] [Accepted: 11/01/2023] [Indexed: 11/30/2023] Open
Abstract
In dioecious populations, males and females may evolve different trait values to increase fitness through their respective sexual functions. Because hermaphrodites express both sexual functions, resolving sexual conflict is potentially more difficult for them. Here, we show that hermaphrodite plants can partially resolve sexual conflict by expressing different trait values in different male and female modules (e.g. different flowers, inflorescences, branches etc.). We analysed the flowering phenology, sex allocation and selection gradients on floral traits of flowers of the andromonoecious plant Pulsatilla alpina, which produces both bisexual and male flowers. Our results indicate that strong protogyny prevents early bisexual flowers from profiting from high siring opportunities early in the reproductive season at a time when male flowers could achieve high siring success. The production of unisexual male flowers thus resolves this sexual conflict because it allows the flowers to express their male function without waiting until after the female function has been performed. Our study illustrates the resolution of sexual conflict arising from phenological constraints via modular divergence in sex allocation. We discuss the extent to which modular variation in sex allocation in the context of other sexual systems may be similarly explained.
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Affiliation(s)
- Kai-Hsiu Chen
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - John R. Pannell
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
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Cutter AD. Sexual conflict, heterochrony and tissue specificity as evolutionary problems of adaptive plasticity in development. Proc Biol Sci 2023; 290:20231854. [PMID: 37817601 PMCID: PMC10565415 DOI: 10.1098/rspb.2023.1854] [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: 08/16/2023] [Accepted: 09/15/2023] [Indexed: 10/12/2023] Open
Abstract
Differential gene expression represents a fundamental cause and manifestation of phenotypic plasticity. Adaptive phenotypic plasticity in gene expression as a trait evolves when alleles that mediate gene regulation serve to increase organismal fitness by improving the alignment of variation in gene expression with variation in circumstances. Among the diverse circumstances that a gene encounters are distinct cell types, developmental stages and sexes, as well as an organism's extrinsic ecological environments. Consequently, adaptive phenotypic plasticity provides a common framework to consider diverse evolutionary problems by considering the shared implications of alleles that produce context-dependent gene expression. From this perspective, adaptive plasticity represents an evolutionary resolution to conflicts of interest that arise from any negatively pleiotropic effects of expression of a gene across ontogeny, among tissues, between the sexes, or across extrinsic environments. This view highlights shared properties within the general relation of fitness, trait expression and context that may nonetheless differ substantively in the grain of selection within and among generations to influence the likelihood of adaptive plasticity as an evolutionary response. Research programmes that historically have focused on these separate issues may use the insights from one another by recognizing their shared dependence on context-dependent gene regulatory evolution.
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Affiliation(s)
- Asher D. Cutter
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada M5S 3B2
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Shi Y, Yao G, Zhang H, Jia H, Xiong P, He M. Proteome and Transcriptome Analysis of Gonads Reveals Intersex in Gigantidas haimaensis. BMC Genomics 2022; 23:174. [PMID: 35240981 PMCID: PMC8892766 DOI: 10.1186/s12864-022-08407-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 02/22/2022] [Indexed: 11/19/2022] Open
Abstract
Sex has proven to be one of the most intriguing areas of research across evolution, development, and ecology. Intersex or sex change occurs frequently in molluscs. The deep-sea mussel Gigantidas haimaensis often dominates within Haima cold seep ecosystems, but details of their reproduction remain unknown. Herein, we conducted a combined proteomic and transcriptomic analysis of G. haimaensis gonads to provide a systematic understanding of sexual development in deep-sea bivalves. A total of 2,452 out of 42,238 genes (5.81%) and 288 out of 7,089 proteins (4.06%) were significantly differentially expressed between ovaries and testes with a false discovery rate (FDR) <0.05. Candidate genes involved in sexual development were identified; among 12 differentially expressed genes between sexes, four ovary-biased genes (β-catenin, fem-1, forkhead box L2 and membrane progestin receptor α) were expressed significantly higher in males than females. Combining histological characteristics, we speculate that the males maybe intersex undergoing sex change, and implied that these genes may be involved in the process of male testis converting into female gonads in G. haimaensis. The results suggest that this adaptation may be based on local environmental factors, sedentary lifestyles, and patchy distribution, and sex change may facilitate adaptation to a changing environment and expansion of the population. The findings provide a valuable genetic resource to better understand the mechanisms of sex change and survival strategies in deep-sea bivalves.
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Affiliation(s)
- Yu Shi
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, China
| | - Gaoyou Yao
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hua Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, China
| | - Huixia Jia
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Panpan Xiong
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Maoxian He
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China. .,Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, China.
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7
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Villamil N, Li X, Seddon E, Pannell JR. Simulated herbivory enhances leaky sex expression in the dioecious herb Mercurialis annua. ANNALS OF BOTANY 2022; 129:79-86. [PMID: 34668537 PMCID: PMC8829902 DOI: 10.1093/aob/mcab129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND AND AIMS Plant reproductive traits are widely understood to be responsive to the selective pressures exerted by pollinators, but there is also increasing evidence for an important role for antagonists such as herbivores in shaping these traits. Many dioecious species show leaky sex expression, with males and females occasionally producing flowers of the opposite sex. Here, we asked to what extent leakiness in sex expression in Mercurialis annua (Euphorbiaceae) might also be plastically responsive to simulated herbivory. This is important because enhanced leakiness in dioecious populations could lead to a shift in both the mating system and in the conditions for transitions between combined and separate sexes. METHODS We examined the effect of simulated herbivory on the sexual expression of males and females of M. annua in two experiments in which different levels of simulated herbivory led to enhanced leakiness in both sexes. KEY RESULTS We showed that leaky sex expression in both males and females of the wind-pollinated dioecious herb M. annua is enhanced in response to simulated herbivory, increasing the probability for and the degree of leakiness in both sexes. We also found that leakiness was greater in larger females but not in larger males. CONCLUSIONS We discuss hypotheses for a possible functional link between herbivory and leaky sex expression, and consider what simulated herbivory-induced leakiness might imply for the evolutionary ecology of plant reproductive systems, especially the breakdown of dioecy and the evolution of hermaphroditism.
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Affiliation(s)
- Nora Villamil
- Department of Ecology and Evolution, Université de Lausanne, Switzerland
| | - Xinji Li
- Department of Ecology and Evolution, Université de Lausanne, Switzerland
| | - Emily Seddon
- Department of Ecology and Evolution, Université de Lausanne, Switzerland
- Vegetation Ecologist, NatureServe, Boulder, CO 80301, USA
| | - John R Pannell
- Department of Ecology and Evolution, Université de Lausanne, Switzerland
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Coelho FF, Damasceno AG, Fávaro A, Teodoro GS, Langsdorff LP. Size-dependent sex allocation in Solanum lycocarpum St. Hil. (Solanaceae). BRAZ J BIOL 2021; 82:e237575. [PMID: 33978077 DOI: 10.1590/1519-6984.237575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 08/19/2020] [Indexed: 11/21/2022] Open
Abstract
Resource allocation to reproduction can change depending on size, as predicted by the size-dependent sex allocation. This theory is based on the fact that small individuals will invest in the allocation of sex with lower cost of production, usually male gender. In plants, there are some andromonoecy species, presence of hermaphrodite and male flowers in the same individual. Andromonoecy provides a strategy to optimally allocate resources to male and female function, evolving a reproductive energy-saving strategy. Thus, our objective was to investigate the size-dependent sex allocation in Solanum lycocarpum St. Hil. We tested the hypothesis that plants with larger size will invest in the production of hermaphrodite flowers, because higher individuals have greater availability of resources to invest in more complex structures involving greater energy expenditure. The studied species was S. lycocarpum, an andromonoecious species. From June 2016 to March 2017 the data were collected in 38 individuals, divided in two groups: the larger plant group (n=18; height=3-5 m) and the smaller plant group (n=20; height=1-2 m).Our data show that there was effect of plant size on the flower production and the sexual gender allocation. The larger plants showed more flowers and higher production of hermaphrodite flowers. Furthermore, in the flower scale, we observed allometric relationship among the flower's traits with proportional investments in biomass, anther size and gynoecium size. Our results are in agreement with size-dependent sex allocation theory and andromonoecy hypothesis related to mechanisms for optimal resource allocation to male and female function.
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Affiliation(s)
- F F Coelho
- Universidade Federal de Lavras - UFLA, Departamento de Biologia, Setor de Botânica, Lavras, MG, Brasil
| | - A G Damasceno
- Universidade Federal de Lavras - UFLA, Departamento de Biologia, Programa de Pós-graduação em Genética, Lavras, MG, Brasil
| | - A Fávaro
- Universidade Federal de Lavras - UFLA, Departamento de Biologia, Programa de Pós-graduação em Ecologia Aplicada, Lavras, MG, Brasil
| | - G S Teodoro
- Universidade Federal do Pará - UFPA, Instituto de Ciências Biológicas, Belém, PA, Brasil
| | - L P Langsdorff
- Universidade Federal de Lavras - UFLA, Departamento de Biologia, Programa de Pós-graduação em Botânica Aplicada, Lavras, MG, Brasil
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9
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Varga S, Soulsbury CD. Environmental stressors affect sex ratios in sexually dimorphic plant sexual systems. PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22:890-898. [PMID: 32333831 DOI: 10.1111/plb.13125] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/29/2020] [Indexed: 06/11/2023]
Abstract
Revealing the environmental pressures determining the frequency of females amongst populations of sexually dimorphic plants is a key research question. Analyses of sex ratio variation have been mainly done in dioecious plants, which misses key plant sexual systems that might represent intermediate stages in the evolution of dioecy from hermaphroditism. We investigated female frequency across populations of sexually dimorphic plant species in relation to environmental stressors (temperature, precipitation), totaling 342 species, 2011 populations, representing 40 orders and three different sexual systems (dioecy, gynodioecy and subdioecy). We also included the biome where the population was located to test how female frequency may vary more broadly with climate conditions. After correcting for phylogeny, our results for gynodioecious systems showed a positive relationship between female frequency and increased environmental stress, with the main effects being temperature-related. Subdioecious systems also showed strong positive relationships with temperature, and positive and negative relationships related to precipitation, while no significant effects on sex ratio in dioecious plants were detected. Combined, we show that female frequencies in an intermediate sexual system on the pathway from hermaphroditism to dioecy respond strongly to environmental stressors and have different selective agents driving female frequency.
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Affiliation(s)
- S Varga
- School of Life Sciences, University of Lincoln, Joseph Banks Laboratories, Lincoln, LN6 7TS, UK
| | - C D Soulsbury
- School of Life Sciences, University of Lincoln, Joseph Banks Laboratories, Lincoln, LN6 7TS, UK
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10
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Blake‐Mahmud J, Struwe L. When the going gets tough, the tough turn female: injury and sex expression in a sex-changing tree. AMERICAN JOURNAL OF BOTANY 2020; 107:339-349. [PMID: 32086802 PMCID: PMC7155049 DOI: 10.1002/ajb2.1427] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 10/14/2019] [Indexed: 05/09/2023]
Abstract
PREMISE Plant sex is usually fixed, but in rare cases, sex expression is flexible and may be influenced by environmental factors. Theory links female sex expression to better health, but manipulative work involving the experimental change of health via injury is limited, particularly in sexually plastic species. A better understanding of mechanisms influencing shifts in sex is essential to our understanding of life history theory regarding trade-offs in sex allocation and differential mortality. METHODS We investigated the relationship between physiological stress and sex expression in sexually plastic striped maple trees (Acer pensylvanicum) by inflicting damage of various intensities (crown pruning, defoliation, and hydraulic restriction). We then monitored the sex expression of injured and control individuals for 2 years to assess the extent to which injury may cue changes in sex expression. RESULTS We found that severe damage such as full defoliation or severe pruning increased odds of changing sex to female and decreased odds of changing to male. In fact, no pruned male trees flowered male 2 years later, while all males in the control group flowered partially or fully male. After full defoliation, trees had 4.5 times higher odds of flowering female. Not all injury is equal; less-severe physical trauma did not affect the frequency of sex change to femaleness. CONCLUSIONS This work demonstrates that physical trauma in striped maple appears to exhibit a threshold effect in which only the most stressful of physiological cues instigate changes in sex expression, a phenomenon previously unknown, and that damage stress is strongly correlated with switching to femaleness. These findings have implications for population sex ratios and sustainability within an increasing stressful climate regime.
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Affiliation(s)
- Jennifer Blake‐Mahmud
- Princeton Writing ProgramPrinceton UniversityPrincetonNJ08544USA
- Department of Ecology, Evolution & Natural ResourcesRutgers UniversityNew BrunswickNJ08901USA
- Present address:
Biology DepartmentColgate University13 Oak DriveHamiltonNY13346USA
| | - Lena Struwe
- Department of Ecology, Evolution & Natural ResourcesRutgers UniversityNew BrunswickNJ08901USA
- Department of Plant BiologyRutgers UniversityNew BrunswickNJ08901USA
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11
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Bialic-Murphy L, Heckel CD, McElderry RM, Kalisz S. Deer Indirectly Alter the Reproductive Strategy and Operational Sex Ratio of an Unpalatable Forest Perennial. Am Nat 2019; 195:56-69. [PMID: 31868539 DOI: 10.1086/706253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Environmental conditions impose restrictions and costs on reproduction. Multiple reproductive options exist when increased reproductive costs drive plant populations toward alternative reproductive strategies. Using 4 years of demographic data across a deer impact gradient, where deer alter the abiotic environment, we parameterize a size-dependent integral projection model for a sexually labile and unpalatable forest perennial to investigate the demographic processes driving differentiation in the operational sex ratio (OSR) of local populations. In addition to a relative increase in asexual reproduction, our results illustrate that nontrophic indirect effects by overabundant deer on this perennial result in delayed female sex expression to unsustainably large plant sizes and lead to more pronounced plant shrinkage following female sex expression, effectively increasing the cost of reproduction. Among plants of reproductive age, increased deer impact decreases the size-dependent probability of flowering and reduces reproductive consistency over time. This pattern in sex expression skews populations toward female-biased OSRs at low deer impact sites and male-biased OSRs at intermediate and high deer impact sites. While this shift toward a male-biased OSR may ameliorate pollen limitation, it also decreases the effective population size when coupled with increased asexual reproduction. The divergence of reproductive strategies and reduced lifetime fitness in response to indirect deer impacts illustrate the persistent long-term effects of overabundant herbivores on unpalatable understory perennials.
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12
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Waples RS, Mariani S, Benvenuto C. Consequences of sex change for effective population size. Proc Biol Sci 2019; 285:20181702. [PMID: 30963897 DOI: 10.1098/rspb.2018.1702] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Sequential hermaphroditism, where males change to females (protandry) or the reverse (protogyny), is widespread in animals and plants, and can be an evolutionarily stable strategy (ESS) if fecundity rises faster with age in the second sex. Sequential hermaphrodites also generally have sex ratios skewed towards the initial sex, and standard theory based on fixed sexes indicates that this should reduce effective population size ( Ne) and increase the deleterious effects of genetic drift. We show that despite having skewed sex ratios, populations that change sex at the ESS age do not have reduced Ne compared with fixed-sex populations with an even sex ratio. This implies that the ability of individuals to operate as both male and female allows the population to avoid some evolutionary constraints imposed by fixed sexes. Furthermore, Ne would be maximized if sex change occurred at a different (generally earlier) age than is selected for at the individual level, which suggests a potential conflict between individual and group selection. We also develop a novel method to quantify the strength of selection for sex reversal.
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Affiliation(s)
- Robin S Waples
- 1 NOAA Fisheries, Northwest Fisheries Science Center , Seattle, WA , USA
| | - Stefano Mariani
- 2 Ecosystems and Environment Research Centre, University of Salford , Salford M54WT , UK
| | - Chiara Benvenuto
- 2 Ecosystems and Environment Research Centre, University of Salford , Salford M54WT , UK
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13
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Lyu Q, Hu J, Yang X, Liu X, Chen Y, Xiao L, Liu Y, Wang Q, Chen J, Huang M, Yu Z, Yang H, Shi H, Zhang Y, Zhao H. Expression profiles of dmrts and foxls during gonadal development and sex reversal induced by 17α-methyltestosterone in the orange-spotted grouper. Gen Comp Endocrinol 2019; 274:26-36. [PMID: 30594589 DOI: 10.1016/j.ygcen.2018.12.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 12/24/2018] [Accepted: 12/26/2018] [Indexed: 12/19/2022]
Abstract
The orange-spotted grouper, Epinephelus coioides, is a marine protogynous hermaphrodite fish of commercial importance. There are many examples of sex change species among marine fish, but the molecular basis for the sex change is still unknown. Gonadal expression patterns of the dmrts and foxls genes in E. coioides have pointed to sexual dimorphism in this species and it has been shown that mRNA levels of dmrts and foxls to vary significantly during reproduction cycles. The steroid 17α-methyltestosterone was used to induce sex reversal in these fish, during which dmrts and foxls levels changed significantly and subsequently reverted to normal when 17α-methyltestosterone was withdrawn. Interestingly, the expression of dmrt2b and dmrt3 was not affected by this steroid. We speculate that the role of foxl2 in reproduction may be conserved via regulation of early differentiation of the ovary by the hypothalamus-pituitary-gonad axis, and dmrt2 may have a significant role in premature ovarian differentiation and maintenance in E. coioides. dmrt1 and foxl3 played a role in the development of the testes and are believed to be potential male regulatory genes.
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Affiliation(s)
- Qingji Lyu
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, People's Republic of China
| | - Juan Hu
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, People's Republic of China
| | - XianKuan Yang
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, People's Republic of China
| | - XiaoChun Liu
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, People's Republic of China
| | - YiBin Chen
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, People's Republic of China
| | - Ling Xiao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, Guangdong, People's Republic of China
| | - YaLi Liu
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, Guangdong, People's Republic of China
| | - Qing Wang
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, People's Republic of China; State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, Guangdong, People's Republic of China
| | - JiaXing Chen
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, Guangdong, People's Republic of China
| | - MinWei Huang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, Guangdong, People's Republic of China
| | - ZeShu Yu
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, Guangdong, People's Republic of China
| | - HuiRong Yang
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, People's Republic of China
| | - HeRong Shi
- Guangdong Marine Fishery Experiment Center, Huizhou 516081, Guangdong, People's Republic of China
| | - Yong Zhang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory for Aquatic Economic Animals and Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, Guangdong, People's Republic of China.
| | - HuiHong Zhao
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, People's Republic of China.
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14
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Repetitive sex change in the stony coral Herpolitha limax across a wide geographic range. Sci Rep 2019; 9:2936. [PMID: 30814532 PMCID: PMC6393666 DOI: 10.1038/s41598-018-37619-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 12/11/2018] [Indexed: 11/08/2022] Open
Abstract
Sex change has been widely studied in animals and plants. However, the conditions favoring sex change, its mode and timing remain poorly known. Here, for the first time in stony corals, we report on a protandrous (youngest individuals are males) repetitive sex change exhibited by the fungiid coral Herpolitha limax across large spatial scales (the coral reefs of Japan, Jordan and Israel) and temporal scales (2004-2017). In contrast to most corals, this species is a daytime spawner (08:00-10:00 AM) that spawned at the same time/same date across all the study sites. The sporadically scattered populations of H. limax among the coral reefs of Eilat (Israel) and Aqaba (Jordan) exhibited significantly slower growth, earlier sex change, and lower percentages of reproduction and sex change in comparison to the densely aggregated populations in Okinawa (Japan). At all sites, sex ratio varied among years, but was almost always biased towards maleness. Growth rate decreased with size. We conclude that comparable to dioecious plants that display labile sexuality in response to energetic and/or environmental constraints, the repetitive sex change displayed by H. limax increases its overall fitness reinforcing the important role of reproductive plasticity in the Phylum Cnidaria in determining their evolutionary success.
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15
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Abstract
Sexual fate can no longer be considered an irreversible deterministic process that once established during early embryonic development, plays out unchanged across an organism's life. Rather, it appears to be a dynamic process, with sexual phenotype determined through an ongoing battle for supremacy between antagonistic male and female developmental pathways. That sexual fate is not final and is actively regulated via the suppression or activation of opposing genetic networks creates the potential for flexibility in sexual phenotype in adulthood. Such flexibility is seen in many fish, where sex change is a usual and adaptive part of the life cycle. Many fish are sequential hermaphrodites, beginning life as one sex and changing sometime later to the other. Sequential hermaphrodites include species capable of female-to-male (protogynous), male-to-female (protandrous), or bidirectional (serial) sex change. These natural forms of sex change involve coordinated transformations across multiple biological systems, including behavioral, anatomical, neuroendocrine and molecular axes. Here we review the biological processes underlying this amazing transformation, focusing particularly on the molecular aspects, where new genomic technologies are beginning to help us understand how sex change is initiated and regulated at the molecular level.
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Affiliation(s)
- Neil J Gemmell
- Department of Anatomy, University of Otago, Dunedin, New Zealand.
| | - Erica V Todd
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | | | | | - Timothy A Hore
- Department of Anatomy, University of Otago, Dunedin, New Zealand
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16
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Wu ZY, Liu J, Provan J, Wang H, Chen CJ, Cadotte MW, Luo YH, Amorim BS, Li DZ, Milne RI. Testing Darwin's transoceanic dispersal hypothesis for the inland nettle family (Urticaceae). Ecol Lett 2018; 21:1515-1529. [PMID: 30133154 DOI: 10.1111/ele.13132] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 04/11/2018] [Accepted: 07/05/2018] [Indexed: 12/17/2022]
Abstract
Dispersal is a fundamental ecological process, yet demonstrating the occurrence and importance of long-distance dispersal (LDD) remains difficult, having rarely been examined for widespread, non-coastal plants. To address this issue, we integrated phylogenetic, molecular dating, biogeographical, ecological, seed biology and oceanographic data for the inland Urticaceae. We found that Urticaceae originated in Eurasia c. 69 Ma, followed by ≥ 92 LDD events between landmasses. Under experimental conditions, seeds of many Urticaceae floated for > 220 days, and remained viable after 10 months in seawater, long enough for most detected LDD events, according to oceanographic current modelling. Ecological traits analyses indicated that preferences for disturbed habitats might facilitate LDD. Nearly half of all LDD events involved dioecious taxa, so population establishment in dioecious Urticaceae requires multiple seeds, or occasional selfing. Our work shows that seawater LDD played an important role in shaping the geographical distributions of Urticaceae, providing empirical evidence for Darwin's transoceanic dispersal hypothesis.
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Affiliation(s)
- Zeng-Yuan Wu
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Jie Liu
- Key Laboratory for Plant and Biodiversity of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Jim Provan
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3DA, UK
| | - Hong Wang
- Key Laboratory for Plant and Biodiversity of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Chia-Jui Chen
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Marc W Cadotte
- Department of Biological Sciences, University of Toronto-Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada.,Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
| | - Ya-Huang Luo
- Key Laboratory for Plant and Biodiversity of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Bruno S Amorim
- Graduate Program in Biotechnology and Natural Resources, School of Health Sciences, State University of Amazonas, CEP, 69065-001, Manaus-AM, Brazil
| | - De-Zhu Li
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China.,Key Laboratory for Plant and Biodiversity of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Richard I Milne
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3JH, UK
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17
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Niu Y, Gong Q, Peng D, Sun H, Li Z. Function of male and hermaphroditic flowers and size-dependent gender diphasy of Lloydia oxycarpa (Liliaceae) from Hengduan Mountains. PLANT DIVERSITY 2017; 39:187-193. [PMID: 30159510 PMCID: PMC6112290 DOI: 10.1016/j.pld.2017.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 06/30/2017] [Accepted: 06/30/2017] [Indexed: 05/23/2023]
Abstract
Although hermaphroditism is common in flowering plants, unisexual flowers occur in many plant taxa, forming various sexual systems. However, the sexual system of some plants is difficult to determine morphologically, given that their sex expression may be influenced by both genetic and environmental factors. Specifically, androdioecy (the coexistence of both male and hermaphroditic individuals in the same population) has often been confused with the gender diphasy, a gender strategy in which plants change their sex expression between seasons. We studied the reproductive function of male and hermaphroditic flowers of Lloydia oxycarpa (Liliaceae), in order to investigate its sexual system and determine whether it is a gender-diphasic species. We found that although male flowers occur in a considerable number of plants, relative to hermaphrodites, they did not exhibit any significant reproductive advantage in terms of flower size, pollen quantity, attractiveness to visitors or siring success. In addition, this plant has spontaneous self-pollination and showed no inbreeding depression. These results render the maintenance of male individuals almost impossible. Furthermore, a considerable number of individuals changed their sex in successive years. The sex expression was found to be related to bulb size and dry weight, with larger individuals producing hermaphroditic flowers and smaller individuals producing male flowers. These results suggest that L. oxycarpa is not an androdioecious plant but represents a rare case of size-dependent gender diphasy.
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Affiliation(s)
- Yang Niu
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, 650201 Kunming, Yunnan, China
| | - Qiangbang Gong
- School of Life Sciences, Yunnan Normal University, 650500 Kunming, Yunnan, China
| | - Deli Peng
- School of Life Sciences, Yunnan Normal University, 650500 Kunming, Yunnan, China
| | - Hang Sun
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, 650201 Kunming, Yunnan, China
| | - Zhimin Li
- School of Life Sciences, Yunnan Normal University, 650500 Kunming, Yunnan, China
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18
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Sawada K, Yamaguchi S, Iwasa Y. Be a good loser: A theoretical model for subordinate decision-making on bi-directional sex change in haremic fishes. J Theor Biol 2017; 421:127-135. [PMID: 28377301 DOI: 10.1016/j.jtbi.2017.03.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 02/19/2017] [Accepted: 03/28/2017] [Indexed: 11/15/2022]
Abstract
Among animals living in groups with reproductive skew associated with a dominance hierarchy, subordinates may do best by using various alternative tactics. Sequential hermaphrodites or sex changers adopt a unique solution, that is, being the sex with weaker skew when they are small and subordinate, and changing sex when they become larger. In bi-directionally sex-changing fishes, although most are haremic and basically protogynous, subordinate males can change sex to being females. We study a mathematical model to examine when and why such reversed sex change is more adaptive than dispersal to take over another harem. We attempt to examine previously proposed hypotheses that the risk of dispersal and low density favor reversed sex change, and to specify an optimal decision-making strategy for subordinates. As a result, while the size-dependent conditional strategy in which smaller males tend to change sex is predicted, even large males are predicted to change sex under low density and/or high risk of dispersal, supporting both previous hypotheses. The importance of spatiotemporal variation of social and ecological conditions is also suggested. We discuss a unified framework to understand hermaphroditic and gonochoristic societies.
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Affiliation(s)
- Kota Sawada
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan.
| | - Sachi Yamaguchi
- Department of Information Systems Creation, Faculty of Engineering, Kanagawa University, Yokohama, Kanagawa 221-8686, Japan
| | - Yoh Iwasa
- Department of Biology, Faculty of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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19
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Garcia MJ, Ferro JM, Mattox T, Kopelic S, Marson K, Jones R, Svendsen JC, Earley RL. Phenotypic differences between the sexes in the sexually plastic mangrove rivulus fish (Kryptolebias marmoratus). ACTA ACUST UNITED AC 2016; 219:988-97. [PMID: 27030777 DOI: 10.1242/jeb.124040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 01/18/2016] [Indexed: 01/23/2023]
Abstract
To maximize reproductive success, many animal species have evolved functional sex change. Theory predicts that transitions between sexes should occur when the fitness payoff of the current sex is exceeded by the fitness payoff of the opposite sex. We examined phenotypic differences between the sexes in a sex-changing vertebrate, the mangrove rivulus fish (Kryptolebias marmoratus), to elucidate potential factors that might drive the 'decision' to switch sex. Rivulus populations consist of self-fertilizing hermaphrodites and males. Hermaphrodites transition into males under certain environmental conditions, affording us the opportunity to generate 40 hermaphrodite-male pairs where, within a pair, individuals possessed identical genotypes despite being different sexes. We quantified steroid hormone levels, behavior (aggression and risk taking), metabolism and morphology (organ masses). We found that hermaphrodites were more aggressive and risk averse, and had higher maximum metabolic rates and larger gonadosomatic indices. Males had higher steroid hormone levels and showed correlations among hormones that hermaphrodites lacked. Males also had greater total mass and somatic body mass and possessed considerable fat stores. Our findings suggest that there are major differences between the sexes in energy allocation, with hermaphrodites exhibiting elevated maximum metabolic rates, and showing evidence of favoring investments in reproductive tissues over somatic growth. Our study serves as the foundation for future research investigating how environmental challenges affect both physiology and reproductive investment and, ultimately, how these changes dictate the transition between sexes.
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Affiliation(s)
- Mark J Garcia
- Department of Biological Sciences, University of Alabama, Box 870344, Tuscaloosa, AL 35473, USA
| | - Jack M Ferro
- Department of Biological Sciences, University of Alabama, Box 870344, Tuscaloosa, AL 35473, USA
| | - Tyler Mattox
- Department of Biological Sciences, University of Alabama, Box 870344, Tuscaloosa, AL 35473, USA
| | - Sydney Kopelic
- Department of Biological Sciences, University of Alabama, Box 870344, Tuscaloosa, AL 35473, USA
| | - Kristine Marson
- Department of Biological Sciences, University of Alabama, Box 870344, Tuscaloosa, AL 35473, USA
| | - Ryan Jones
- Department of Biological Sciences, University of Alabama, Box 870344, Tuscaloosa, AL 35473, USA
| | - Jon C Svendsen
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4050-123 Porto, Portugal Section for Ecosystem based Marine Management, National Institute of Aquatic Resources (DTU Aqua), Technical University of Denmark, 2920 Charlottenlund, Denmark
| | - Ryan L Earley
- Department of Biological Sciences, University of Alabama, Box 870344, Tuscaloosa, AL 35473, USA
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20
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Todd EV, Liu H, Muncaster S, Gemmell NJ. Bending Genders: The Biology of Natural Sex Change in Fish. Sex Dev 2016; 10:223-241. [PMID: 27820936 DOI: 10.1159/000449297] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Indexed: 11/19/2022] Open
Abstract
Sexual fate is no longer seen as an irreversible deterministic switch set during early embryonic development but as an ongoing battle for primacy between male and female developmental trajectories. That sexual fate is not final and must be actively maintained via continuous suppression of the opposing sexual network creates the potential for flexibility into adulthood. In many fishes, sexuality is not only extremely plastic, but sex change is a usual and adaptive part of the life cycle. Sequential hermaphrodites begin life as one sex, changing sometime later to the other, and include species capable of protandrous (male-to-female), protogynous (female-to-male), or serial (bidirectional) sex change. Natural sex change involves coordinated transformations across multiple biological systems, including behavioural, anatomical, neuroendocrine, and molecular axes. We here review the biological processes underlying this amazing transformation, focussing particularly on its molecular basis, which remains poorly understood, but where new genomic technologies are significantly advancing our understanding of how sex change is initiated and progressed at the molecular level. Knowledge of how a usually committed developmental process remains plastic in sequentially hermaphroditic fishes is relevant to understanding the evolution and functioning of sexual developmental systems in vertebrates generally, as well as pathologies of sexual development in humans.
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Affiliation(s)
- Erica V Todd
- Department of Anatomy, University of Otago, Dunedin, New Zealand
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21
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Varga S, Kytöviita MM. Light availability affects sex lability in a gynodioecious plant. AMERICAN JOURNAL OF BOTANY 2016; 103:1928-1936. [PMID: 27864260 DOI: 10.3732/ajb.1600158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 10/27/2016] [Indexed: 06/06/2023]
Abstract
PREMISE OF THE STUDY Sex lability (i.e., gender diphasy) in plants is classically linked to the larger resource needs associated with the female sexual function (i.e., seed production) compared to the male function (i.e., pollen production). Sex lability in response to the environment is extensively documented in dioecious species, but has been largely overlooked in gynodioecious plants. METHODS Here, we tested whether environmental conditions induce sex lability in the gynodioecious Geranium sylvaticum. We conducted a transplantation experiment in the field where plants with different sex expression were reciprocally transplanted between high light and low light habitats. We measured plants' reproductive output and sex expression over four years. KEY RESULTS Our results show that sex expression was labile over the study period. The light level at the destination habitat had a significant effect on sexual expression and reproductive output, because plants decreased their reproductive output when transplanted to the low light habitat. Transplantation origin did not affect any parameter measured. CONCLUSIONS This study shows that sex expression in Geranium sylvaticum is labile and related to light availability. Sexually labile plants did not produce more seeds or pollen, and thus, there was no apparent fitness gain in sexually labile individuals. Sex lability in gynodioecious plants may be more common than previously believed because detection of sex lability necessitates data on the same individuals over time, which is rare in sexually dimorphic herbaceous plants.
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Affiliation(s)
- Sandra Varga
- Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35 40014 Jyvaskyla, Finland
| | - Minna-Maarit Kytöviita
- Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35 40014 Jyvaskyla, Finland
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22
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Liu H, Todd EV, Lokman PM, Lamm MS, Godwin JR, Gemmell NJ. Sexual plasticity: A fishy tale. Mol Reprod Dev 2016; 84:171-194. [PMID: 27543780 DOI: 10.1002/mrd.22691] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/16/2016] [Indexed: 01/08/2023]
Abstract
Teleost fish exhibit remarkably diverse and plastic patterns of sexual development. One of the most fascinating modes of plasticity is functional sex change, which is widespread in marine fish including species of commercial importance; however, the regulatory mechanisms remain elusive. In this review, we explore such sexual plasticity in fish, using the bluehead wrasse (Thalassoma bifasciatum) as the primary model. Synthesizing current knowledge, we propose that cortisol and key neurochemicals modulate gonadotropin releasing hormone and luteinizing hormone signaling to promote socially controlled sex change in protogynous fish. Future large-scale genomic analyses and systematic comparisons among species, combined with manipulation studies, will likely uncover the common and unique pathways governing this astonishing transformation. Revealing the molecular and neuroendocrine mechanisms underlying sex change in fish will greatly enhance our understanding of vertebrate sex determination and differentiation as well as phenotypic plasticity in response to environmental influences. Mol. Reprod. Dev. 84: 171-194, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Hui Liu
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Erica V Todd
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - P Mark Lokman
- Department of Zoology, University of Otago, Dunedin, New Zealand
| | - Melissa S Lamm
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina.,W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina
| | - John R Godwin
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina.,W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina
| | - Neil J Gemmell
- Department of Anatomy, University of Otago, Dunedin, New Zealand
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23
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Lankinen Å, Niss J, Madjidian JA. Effect of root contact on pollen competitive ability in a hermaphroditic winter-annual herb. Evol Ecol 2016. [DOI: 10.1007/s10682-016-9839-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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24
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25
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Zhang ZQ, Zhu XF, Sun H, Yang YP, Barrett SCH. Size-dependent gender modification in Lilium apertum (Liliaceae): does this species exhibit gender diphasy? ANNALS OF BOTANY 2014; 114:441-53. [PMID: 25062885 PMCID: PMC4204668 DOI: 10.1093/aob/mcu140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Variation in the relative female and male reproductive success of flowering plants is widespread, despite the fundamental hermaphroditic condition of the majority of species. In many hermaphroditic populations, environmental conditions and their influence on development and size can influence the gender expression of individuals through the formation of hermaphroditic and unisexual flowers. This study investigates the hypothesis that the bulbous, animal-pollinated, perennial Lilium apertum (Liliaceae) exhibits a form of size-dependent gender modification known as gender diphasy, in which the sexual expression of individuals depends on their size, with plants often changing sex between seasons. METHODS Variation in floral traits was examined in relation to their size using marked individuals in natural populations, and also under glasshouse conditions. Measurements were taken of the height, flower number, floral sex expression, flower size, flower biomass and pollen production of individuals over consecutive years between 2009 and 2012 in seven populations in south-west China. KEY RESULTS Flowers of L. apertum are either perfect (hermaphroditic) or staminate (male) and, in any given season, plants exhibit one of three sex phenotypes: only hermaphrodite flowers, a mixture of hermaphroditic and male flowers, or only male flowers. Transitions between each of these sex phenotypes were observed over consecutive years and were commonly size-dependent, particularly transitions from small plants bearing only male flowers to those that were taller with hermaphroditic flowers. Hermaphroditic flowers were significantly larger, heavier and produced more pollen than male flowers. CONCLUSIONS The results for L. apertum are consistent with the 'size advantage hypothesis' developed for animal species with sex change. The theory predicts that when individuals are small they should exhibit the sex for which the costs of reproduction are less, and this usually involves the male phase. L. apertum provides an example of gender diphasy, a rare sexual system in flowering plants.
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Affiliation(s)
- Zhi-Qiang Zhang
- Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650204, Yunnan, China Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun Town 666303, Yunnan, China
| | - Xing-Fu Zhu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun Town 666303, Yunnan, China
| | - Hang Sun
- Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650204, Yunnan, China
| | - Yong-Ping Yang
- Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650204, Yunnan, China Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, Yunnan, China
| | - Spencer C H Barrett
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2, Canada
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