1
|
Hasunuma I. Central regulation of reproduction in amphibians. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024; 341:219-229. [PMID: 38084833 DOI: 10.1002/jez.2769] [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: 06/30/2023] [Revised: 11/22/2023] [Accepted: 11/27/2023] [Indexed: 02/27/2024]
Abstract
This review article includes a literature review of synteny analysis of the amphibian gonadotropin-releasing hormone (GnRH) genes, the distribution of GnRH 1 and GnRH2 neurons in the central nervous system of amphibians, the function and regulation of hypophysiotropic GnRH1, and the function of GnRH1 in amphibian reproductive behaviors. It is generally accepted that GnRH is the key regulator of the hypothalamic-pituitary-gonadal axis. Three independent GnRH genes, GnRH1, GnRH2, and GnRH3, have been identified in vertebrates. Previous genome synteny analyses suggest that there are likely just two genes, gnrh1 and gnrh2, in amphibians. In three groups of amphibians: Anura, Urodela, and Gymnophiona, the distributions of GnRH1 and GnRH2 neurons in the central nervous system have also been previously reported. Moreover, these neuronal networks were determined to be structurally independent in all species examined. The somata of GnRH1 neurons are located in the terminal nerve, medial septum (MS), and preoptic area (POA), and some GnRH1 neurons in the MS and POA project into the median eminence. In contrast, the somata of GnRH2 neurons are located in the midbrain tegmentum. In amphibians, GnRH1 neurons originate from the embryonic olfactory placode, while GnRH2 neurons originate from the midbrain. The characterization and feedback regulation mechanisms of hypophysiotropic GnRH1 neurons in amphibians, the involvement of GnRH1 in amphibian reproductive behavior, and its possible mechanism of action should be elucidated in future.
Collapse
Affiliation(s)
- Itaru Hasunuma
- Department of Biology, Faculty of Science, Toho University, Funabashi, Chiba, Japan
| |
Collapse
|
2
|
Zhou Z, Ding L, Liu Z, Fu L, Xu L, Feng L, Yu S, Li P, Zhou Y. The complete mitochondrial genome of Goniurosaurus varius (Squamata: Eublepharidae). Mitochondrial DNA B Resour 2023; 8:1215-1219. [PMID: 38239912 PMCID: PMC10796122 DOI: 10.1080/23802359.2023.2278817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 10/29/2023] [Indexed: 01/22/2024] Open
Abstract
The complete mitochondrial genome sequence of Goniurosaurus varius is 17778 bp in length (GenBank accession number OQ992199), containing 13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes. The gene order and orientation are identical to those of other Eublepharidae species in the GenBank database. Seven protein-coding genes (COX2, COX3, ND1, ND2, ND3, ND4 and CYTB) exhibit incomplete stop codon 'T.' Phylogenetic analysis revealed the monophyly of Goniurosaurus and Eublepharidae and suggested that G. varius is closely related to the lineage composed of G. luii and G. liboensis. Distinct from other published Eublepharidae species, G. varius contains an extra non-coding region between tRNA-Thr and tRNA-Pro, which may be formed by gene rearrangements. The complete mitochondrial genome will be helpful for further studies on the population genetics of this species and phylogenetic analyses of Eublepharidae.
Collapse
Affiliation(s)
- Zhengyan Zhou
- College of Life Science and bioengineering, Shenyang University, Shenyang, China
| | - Lin Ding
- College of Life Science and bioengineering, Shenyang University, Shenyang, China
| | - Ziyi Liu
- College of Life Science and bioengineering, Shenyang University, Shenyang, China
| | - Longming Fu
- College of Life Science and bioengineering, Shenyang University, Shenyang, China
| | - Lanying Xu
- College of Life Science and bioengineering, Shenyang University, Shenyang, China
| | - Lin Feng
- College of Life Science and bioengineering, Shenyang University, Shenyang, China
| | - Sufan Yu
- College of Life Science and bioengineering, Shenyang University, Shenyang, China
| | - Pipeng Li
- Institute of Herpetology, Shenyang Normal University, Shenyang, China
| | - Yu Zhou
- College of Life Science, Shenyang Normal University, Shenyang, China
| |
Collapse
|
3
|
Guo L, Kruglyak L. Genetics and biology of coloration in reptiles: the curious case of the Lemon Frost geckos. Physiol Genomics 2023; 55:479-486. [PMID: 37642275 DOI: 10.1152/physiolgenomics.00015.2023] [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: 03/06/2023] [Revised: 08/17/2023] [Accepted: 08/23/2023] [Indexed: 08/31/2023] Open
Abstract
Although there are more than 10,000 reptile species, and reptiles have historically contributed to our understanding of biology, genetics research into class Reptilia has lagged compared with other animals. Here, we summarize recent progress in genetics of coloration in reptiles, with a focus on the leopard gecko, Eublepharis macularius. We highlight genetic approaches that have been used to examine variation in color and pattern formation in this species as well as to provide insights into mechanisms underlying skin cancer. We propose that their long breeding history in captivity makes leopard geckos one of the most promising emerging reptilian models for genetic studies. More broadly, technological advances in genetics, genomics, and gene editing may herald a golden era for studies of reptile biology.
Collapse
Affiliation(s)
- Longhua Guo
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, United States
- Geriatrics Center and Institute of Gerontology, University of Michigan, Ann Arbor, Michigan, United States
| | - Leonid Kruglyak
- Department of Human Genetics, University of California, Los Angeles, California, United States
- Department of Biological Chemistry, University of California, Los Angeles, California, United States
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States
| |
Collapse
|
4
|
Hastings BT, Melnyk A, Ghyabi M, White E, Barroso FM, Carretero MA, Lattanzi D, Claude J, Chiari Y. Melanistic coloration does not influence thermoregulation in the crepuscular gecko Eublepharis macularius. Biol Open 2023; 12:bio060114. [PMID: 37756597 PMCID: PMC10651090 DOI: 10.1242/bio.060114] [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: 08/21/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
Body coloration in ectotherms serves multiple biological functions, including avoiding predators, communicating with conspecific individuals, and involvement in thermoregulation. As ectotherms rely on environmental sources of heat to regulate their internal body temperature, stable melanistic body coloration or color change can be used to increase or decrease heat absorption and heat exchange with the environment. While melanistic coloration for thermoregulation functions to increase solar radiation absorption and consequently heating in many diurnal ectotherms, research on crepuscular and nocturnal ectotherms is lacking. Since crepuscular and nocturnal ectotherms generally absorb heat from the substrate, in these organisms melanistic coloration may have other primary functions beside thermoregulation. As such, in this work we hypothesized that the proportion of dorsal melanistic body coloration would not influence heating and cooling rates in the crepuscular gecko, Eublepharis macularius, and that changes in environmental temperature would not trigger color changes in this species. Temperature measurements of the geckos and of the environment were taken using infrared thermography and temperature loggers. Color data were obtained using objective photography and a newly developed custom software package. We found that body temperature reflected substrate temperatures, and that the proportion of melanistic coloration has no influence on heating or cooling rates or on color changes. These findings support that melanistic coloration in E. macularius may not be used for thermoregulation and strengthen the hypothesis that in animals active in low light conditions, melanistic coloration may be used instead for camouflage or other functions.
Collapse
Affiliation(s)
| | - Anastasiya Melnyk
- Department of Biology, George Mason University, Fairfax, VA 22030, USA
| | - Mehrdad Ghyabi
- Department of Civil, Environmental, and Infrastructure Engineering, George Mason University, Fairfax, VA 22030, USA
| | - Emma White
- Department of Biology, George Mason University, Fairfax, VA 22030, USA
| | - Frederico M. Barroso
- CIBIO, Research Centre in Biodiversity and Genetic Resources, InBIO, Universidade do Porto, Campus de Vairão, Rua Padre Armando Quintas, 4485-661 Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4099-002 Porto, Portugal
| | - Miguel A. Carretero
- CIBIO, Research Centre in Biodiversity and Genetic Resources, InBIO, Universidade do Porto, Campus de Vairão, Rua Padre Armando Quintas, 4485-661 Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4099-002 Porto, Portugal
| | - David Lattanzi
- Department of Civil, Environmental, and Infrastructure Engineering, George Mason University, Fairfax, VA 22030, USA
| | - Julien Claude
- Institute of Evolutionary Science of Montpellier, University of Montpellier/CNRS/IRD, Montpellier 34095, France
- Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Ylenia Chiari
- Department of Biology, George Mason University, Fairfax, VA 22030, USA
| |
Collapse
|
5
|
Lisachov A, Tishakova K, Romanenko S, Lisachova L, Davletshina G, Prokopov D, Kratochvíl L, O Brien P, Ferguson-Smith M, Borodin P, Trifonov V. Robertsonian fusion triggers recombination suppression on sex chromosomes in Coleonyx geckos. Sci Rep 2023; 13:15502. [PMID: 37726346 PMCID: PMC10509250 DOI: 10.1038/s41598-023-39937-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 08/02/2023] [Indexed: 09/21/2023] Open
Abstract
The classical hypothesis proposes that the lack of recombination on sex chromosomes arises due to selection for linkage between a sex-determining locus and sexually antagonistic loci, primarily facilitated by inversions. However, cessation of recombination on sex chromosomes could be attributed also to neutral processes, connected with other chromosome rearrangements or can reflect sex-specific recombination patterns existing already before sex chromosome differentiation. Three Coleonyx gecko species share a complex X1X1X2X2/X1X2Y system of sex chromosomes evolved via a fusion of the Y chromosome with an autosome. We analyzed synaptonemal complexes and sequenced flow-sorted sex chromosomes to investigate the effect of chromosomal rearrangement on recombination and differentiation of these sex chromosomes. The gecko sex chromosomes evolved from syntenic regions that were also co-opted also for sex chromosomes in other reptiles. We showed that in male geckos, recombination is less prevalent in the proximal regions of chromosomes and is even further drastically reduced around the centromere of the neo-Y chromosome. We highlight that pre-existing recombination patterns and Robertsonian fusions can be responsible for the cessation of recombination on sex chromosomes and that such processes can be largely neutral.
Collapse
Affiliation(s)
- Artem Lisachov
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, Bangkok, 10900, Thailand.
- Institute of Environmental and Agricultural Biology (X-BIO), University of Tyumen, Tyumen, 625003, Russia.
- Institute of Cytology and Genetics, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia.
| | - Katerina Tishakova
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia
- Novosibirsk State University, Novosibirsk, 630090, Russia
| | - Svetlana Romanenko
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia
| | - Lada Lisachova
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia
- Novosibirsk State University, Novosibirsk, 630090, Russia
| | - Guzel Davletshina
- Institute of Cytology and Genetics, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia
| | - Dmitry Prokopov
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, 12844, Prague, Czech Republic
| | - Patricia O Brien
- Department of Veterinary Medicine, Cambridge Resource Centre for Comparative Genomics, University of Cambridge, Cambridge, CB3 0ES, UK
| | - Malcolm Ferguson-Smith
- Department of Veterinary Medicine, Cambridge Resource Centre for Comparative Genomics, University of Cambridge, Cambridge, CB3 0ES, UK
| | - Pavel Borodin
- Institute of Cytology and Genetics, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia
| | - Vladimir Trifonov
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia
| |
Collapse
|
6
|
Pinto BJ, Gamble T, Smith CH, Wilson MA. A lizard is never late: Squamate genomics as a recent catalyst for understanding sex chromosome and microchromosome evolution. J Hered 2023; 114:445-458. [PMID: 37018459 PMCID: PMC10445521 DOI: 10.1093/jhered/esad023] [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: 01/20/2023] [Accepted: 04/03/2023] [Indexed: 04/07/2023] Open
Abstract
In 2011, the first high-quality genome assembly of a squamate reptile (lizard or snake) was published for the green anole. Dozens of genome assemblies were subsequently published over the next decade, yet these assemblies were largely inadequate for answering fundamental questions regarding genome evolution in squamates due to their lack of contiguity or annotation. As the "genomics age" was beginning to hit its stride in many organismal study systems, progress in squamates was largely stagnant following the publication of the green anole genome. In fact, zero high-quality (chromosome-level) squamate genomes were published between the years 2012 and 2017. However, since 2018, an exponential increase in high-quality genome assemblies has materialized with 24 additional high-quality genomes published for species across the squamate tree of life. As the field of squamate genomics is rapidly evolving, we provide a systematic review from an evolutionary genomics perspective. We collated a near-complete list of publicly available squamate genome assemblies from more than half-a-dozen international and third-party repositories and systematically evaluated them with regard to their overall quality, phylogenetic breadth, and usefulness for continuing to provide accurate and efficient insights into genome evolution across squamate reptiles. This review both highlights and catalogs the currently available genomic resources in squamates and their ability to address broader questions in vertebrates, specifically sex chromosome and microchromosome evolution, while addressing why squamates may have received less historical focus and has caused their progress in genomics to lag behind peer taxa.
Collapse
Affiliation(s)
- Brendan J Pinto
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ, United States
- Department of Zoology, Milwaukee Public Museum, Milwaukee, WI, United States
| | - Tony Gamble
- Department of Zoology, Milwaukee Public Museum, Milwaukee, WI, United States
- Department of Biological Sciences, Marquette University, Milwaukee, WI, United States
- Bell Museum of Natural History, University of Minnesota, St Paul, MN, United States
| | - Chase H Smith
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, United States
| | - Melissa A Wilson
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ, United States
- Center for Mechanisms of Evolution, Biodesign Institute, Tempe, AZ, United States
| |
Collapse
|