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Kuhl H, Tan WH, Klopp C, Kleiner W, Koyun B, Ciorpac M, Feron R, Knytl M, Kloas W, Schartl M, Winkler C, Stöck M. A candidate sex determination locus in amphibians which evolved by structural variation between X- and Y-chromosomes. Nat Commun 2024; 15:4781. [PMID: 38839766 PMCID: PMC11153619 DOI: 10.1038/s41467-024-49025-2] [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: 10/20/2023] [Accepted: 05/17/2024] [Indexed: 06/07/2024] Open
Abstract
Most vertebrates develop distinct females and males, where sex is determined by repeatedly evolved environmental or genetic triggers. Undifferentiated sex chromosomes and large genomes have caused major knowledge gaps in amphibians. Only a single master sex-determining gene, the dmrt1-paralogue (dm-w) of female-heterogametic clawed frogs (Xenopus; ZW♀/ZZ♂), is known across >8740 species of amphibians. In this study, by combining chromosome-scale female and male genomes of a non-model amphibian, the European green toad, Bufo(tes) viridis, with ddRAD- and whole genome pool-sequencing, we reveal a candidate master locus, governing a male-heterogametic system (XX♀/XY♂). Targeted sequencing across multiple taxa uncovered structural X/Y-variation in the 5'-regulatory region of the gene bod1l, where a Y-specific non-coding RNA (ncRNA-Y), only expressed in males, suggests that this locus initiates sex-specific differentiation. Developmental transcriptomes and RNA in-situ hybridization show timely and spatially relevant sex-specific ncRNA-Y and bod1l-gene expression in primordial gonads. This coincided with differential H3K4me-methylation in pre-granulosa/pre-Sertoli cells, pointing to a specific mechanism of amphibian sex determination.
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Affiliation(s)
- Heiner Kuhl
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, IGB, Müggelseedamm 301 & 310, 12587, Berlin, Germany
| | - Wen Hui Tan
- Department of Biological Sciences and Centre for Bioimaging Sciences, National University of Singapore, 14 Science Drive 4, Block S1A, Level 6, Singapore, 117543, Singapore
| | - Christophe Klopp
- SIGENAE, Plate-forme Bio-informatique Genotoul, Mathématiques et Informatique Appliquées de Toulouse, INRAe, 31326, Castanet-Tolosan, France
| | - Wibke Kleiner
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, IGB, Müggelseedamm 301 & 310, 12587, Berlin, Germany
| | - Baturalp Koyun
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, IGB, Müggelseedamm 301 & 310, 12587, Berlin, Germany
- Department of Molecular Biology and Genetics, Genetics, Faculty of Science, Bilkent University, SB Building, Ankara, 06800, Turkey
| | - Mitica Ciorpac
- Danube Delta National Institute for Research and Development, Tulcea, 820112, Romania
- Advanced Research and Development Center for Experimental Medicine-CEMEX, "Grigore T. Popa", University of Medicine and Pharmacy, Mihail Kogălniceanu Street 9-13, Iasi, 700259, Romania
| | - Romain Feron
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Martin Knytl
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, Prague, 12843, Czech Republic
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, L8S 4K1, Ontario, ON, Canada
| | - Werner Kloas
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, IGB, Müggelseedamm 301 & 310, 12587, Berlin, Germany
| | - Manfred Schartl
- Developmental Biochemistry, Biocenter, University of Wuerzburg, Am Hubland, 97074, Wuerzburg, Germany
- The Xiphophorus Genetic Stock Center, Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, 78666, USA
| | - Christoph Winkler
- Department of Biological Sciences and Centre for Bioimaging Sciences, National University of Singapore, 14 Science Drive 4, Block S1A, Level 6, Singapore, 117543, Singapore.
| | - Matthias Stöck
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, IGB, Müggelseedamm 301 & 310, 12587, Berlin, Germany.
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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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Xu W, Li T, Li J, Liu S, Yu X, Tang M, Dong J, Liu J, Bu X, Xia X, Zhou H, Nie L. The First Identification of Homomorphic XY Sex Chromosomes by Integrating Cytogenetic and Transcriptomic Approaches in Plestiodon elegans (Scincidae). Genes (Basel) 2024; 15:664. [PMID: 38927599 PMCID: PMC11203037 DOI: 10.3390/genes15060664] [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: 04/16/2024] [Revised: 05/14/2024] [Accepted: 05/22/2024] [Indexed: 06/28/2024] Open
Abstract
The sex chromosomes of skinks are usually poorly differentiated and hardly distinguished by cytogenetic methods. Therefore, identifying sex chromosomes in species lacking easily recognizable heteromorphic sex chromosomes is necessary to fully understand sex chromosome diversity. In this paper, we employed cytogenetics, sex quantification of genes, and transcriptomic approaches to characterize the sex chromosomes in Plestiodon elegans. Cytogenetic examination of metaphases revealed a diploid number of 2n = 26, consisting of 12 macrochromosomes and 14 microchromosomes, with no significant heteromorphic chromosome pairs, speculating that the sex chromosomes may be homomorphic or poorly differentiated. The results of the sex quantification of genes showed that Calumenin (calu), COPI coat complex subunit γ 2 (copg2), and Smoothened (smo) were at half the dose in males as in females, suggesting that they are on the X chromosome. Transcriptomic data analysis from the gonads yielded the excess expression male-specific genes (n = 16), in which five PCR molecular markers were developed. Restricting the observed heterozygosity to males suggests the presence of homomorphic sex chromosomes in P. elegans, XX/XY. This is the first breakthrough in the study of the sex chromosomes of Plestiodon.
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Affiliation(s)
- Wannan Xu
- The Anhui Provincial Key Laboratory of Biodiversity Conservation and Ecological Security in the Yangtze River Basin, College of Life Sciences, Anhui Normal University, Wuhu 241000, China; (W.X.); (T.L.); (J.L.); (S.L.); (X.Y.); (M.T.); (J.D.); (X.B.); (X.X.)
- Wuxi People’s Hospital Affiliated to Nanjing Medical University, Wuxi 214023, China
| | - Taiyue Li
- The Anhui Provincial Key Laboratory of Biodiversity Conservation and Ecological Security in the Yangtze River Basin, College of Life Sciences, Anhui Normal University, Wuhu 241000, China; (W.X.); (T.L.); (J.L.); (S.L.); (X.Y.); (M.T.); (J.D.); (X.B.); (X.X.)
| | - Jiahui Li
- The Anhui Provincial Key Laboratory of Biodiversity Conservation and Ecological Security in the Yangtze River Basin, College of Life Sciences, Anhui Normal University, Wuhu 241000, China; (W.X.); (T.L.); (J.L.); (S.L.); (X.Y.); (M.T.); (J.D.); (X.B.); (X.X.)
| | - Siqi Liu
- The Anhui Provincial Key Laboratory of Biodiversity Conservation and Ecological Security in the Yangtze River Basin, College of Life Sciences, Anhui Normal University, Wuhu 241000, China; (W.X.); (T.L.); (J.L.); (S.L.); (X.Y.); (M.T.); (J.D.); (X.B.); (X.X.)
| | - Xing Yu
- The Anhui Provincial Key Laboratory of Biodiversity Conservation and Ecological Security in the Yangtze River Basin, College of Life Sciences, Anhui Normal University, Wuhu 241000, China; (W.X.); (T.L.); (J.L.); (S.L.); (X.Y.); (M.T.); (J.D.); (X.B.); (X.X.)
| | - Min Tang
- The Anhui Provincial Key Laboratory of Biodiversity Conservation and Ecological Security in the Yangtze River Basin, College of Life Sciences, Anhui Normal University, Wuhu 241000, China; (W.X.); (T.L.); (J.L.); (S.L.); (X.Y.); (M.T.); (J.D.); (X.B.); (X.X.)
| | - Jingxiu Dong
- The Anhui Provincial Key Laboratory of Biodiversity Conservation and Ecological Security in the Yangtze River Basin, College of Life Sciences, Anhui Normal University, Wuhu 241000, China; (W.X.); (T.L.); (J.L.); (S.L.); (X.Y.); (M.T.); (J.D.); (X.B.); (X.X.)
| | - Jianjun Liu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210098, China;
| | - Xingjiang Bu
- The Anhui Provincial Key Laboratory of Biodiversity Conservation and Ecological Security in the Yangtze River Basin, College of Life Sciences, Anhui Normal University, Wuhu 241000, China; (W.X.); (T.L.); (J.L.); (S.L.); (X.Y.); (M.T.); (J.D.); (X.B.); (X.X.)
| | - Xingquan Xia
- The Anhui Provincial Key Laboratory of Biodiversity Conservation and Ecological Security in the Yangtze River Basin, College of Life Sciences, Anhui Normal University, Wuhu 241000, China; (W.X.); (T.L.); (J.L.); (S.L.); (X.Y.); (M.T.); (J.D.); (X.B.); (X.X.)
| | - Huaxing Zhou
- Anhui Key Laboratory of Aquaculture & Stock Enhancement, Fisheries Research Institution, Anhui Academy of Agricultural Sciences, Hefei 230041, China
| | - Liuwang Nie
- The Anhui Provincial Key Laboratory of Biodiversity Conservation and Ecological Security in the Yangtze River Basin, College of Life Sciences, Anhui Normal University, Wuhu 241000, China; (W.X.); (T.L.); (J.L.); (S.L.); (X.Y.); (M.T.); (J.D.); (X.B.); (X.X.)
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Peš T, Straková B, Kratochvíl L. Environmental (and Random?) Sex Determination in Endangered and Invasive Phelsuma Geckos. Sex Dev 2024:1-6. [PMID: 38615656 DOI: 10.1159/000538906] [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: 01/29/2024] [Accepted: 04/12/2024] [Indexed: 04/16/2024] Open
Abstract
INTRODUCTION Sex is a fundamental characteristic of an individual. It is therefore puzzling why in some systems sex is precisely determined by a genotype, while in others it is influenced by the environment or even subtle, not to say random, factors. Some stochasticity in sex determination would be expected if environmental conditions did not have a large sex-specific effect on fitness. Although data are only available for a small fraction of species, geckos show exceptional variability in sex determination. METHODS We tested the effects of three incubation temperatures on sex ratio and adult body size in the invasive gecko Phelsuma laticauda and the vulnerable gecko Phelsuma nigristriata. RESULTS We document temperature-dependent sex determination (TSD) in both species. Only females hatched at a low temperature (24°C), whereas male production peaked at an intermediate temperature (28°C) and declined, at least in P. laticauda, again at the highest temperature (31°C). Interestingly, full siblings hatched from eggs glued together during the incubation at temperatures producing both sexes are often of the opposite sex. We found no significant effect of incubation temperature on adult body length. CONCLUSIONS Documentation of TSD in the day geckos has implications for conservation practice in environmental management of endangered species or eradication of invasive species. However, it appears that a very subtle (random?) factor may also be involved in their sex determination. In line with this, we found no significant effect of incubation temperature on adult body length.
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Affiliation(s)
- Tomáš Peš
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
- Zoological and Botanical Garden of the city of Pilsen, Plzeň, Czechia
| | - Barbora Straková
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
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Saunders PA, Ferre-Ortega C, Hill PL, Simakov O, Ezaz T, Burridge CP, Wapstra E. Using a Handful of Transcriptomes to Detect Sex-Linked Markers and Develop Molecular Sexing Assays in a Species with Homomorphic Sex Chromosomes. Genome Biol Evol 2024; 16:evae060. [PMID: 38526014 PMCID: PMC11003529 DOI: 10.1093/gbe/evae060] [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: 08/04/2023] [Revised: 03/12/2024] [Accepted: 03/17/2024] [Indexed: 03/26/2024] Open
Abstract
To understand the biology of a species, it is often crucial to be able to differentiate males and females. However, many species lack easily identifiable sexually dimorphic traits. In those that possess sex chromosomes, molecular sexing offers a good alternative, and molecular sexing assays can be developed through the comparison of male and female genomic sequences. However, in many nonmodel species, sex chromosomes are poorly differentiated, and identifying sex-linked sequences and developing sexing assays can be challenging. In this study, we highlight a simple transcriptome-based procedure for the detection of sex-linked markers suitable for the development of sexing assays that circumvents limitations of more commonly used approaches. We apply it to the spotted snow skink Carinascincus ocellatus, a viviparous lizard with homomorphic XY chromosomes that has environmentally induced sex reversal. With transcriptomes from three males and three females alone, we identify thousands of putative Y-linked sequences. We confirm linkage through alignment of assembled transcripts to a distantly related lizard genome and readily design multiple single locus polymerase chain reaction primers to sex C. ocellatus and related species. Our approach also facilitates valuable comparisons of sex determining systems on a broad taxonomic scale.
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Affiliation(s)
- Paul A Saunders
- Discipline of Biological Sciences, University of Tasmania, Sandy Bay, Tasmania 7000, Australia
| | - Carles Ferre-Ortega
- Discipline of Biological Sciences, University of Tasmania, Sandy Bay, Tasmania 7000, Australia
| | - Peta L Hill
- Institute for Applied Ecology, University of Canberra, Bruce, Australian Capital Territory 2601, Australia
| | - Oleg Simakov
- Department of Molecular Evolution and Development, University of Vienna, Vienna 1010, Austria
| | - Tariq Ezaz
- Institute for Applied Ecology, University of Canberra, Bruce, Australian Capital Territory 2601, Australia
| | - Christopher P Burridge
- Discipline of Biological Sciences, University of Tasmania, Sandy Bay, Tasmania 7000, Australia
| | - Erik Wapstra
- Discipline of Biological Sciences, University of Tasmania, Sandy Bay, Tasmania 7000, Australia
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Rovatsos M, Mazzoleni S, Augstenová B, Altmanová M, Velenský P, Glaw F, Sanchez A, Kratochvíl L. Heteromorphic ZZ/ZW sex chromosomes sharing gene content with mammalian XX/XY are conserved in Madagascan chameleons of the genus Furcifer. Sci Rep 2024; 14:4898. [PMID: 38418601 PMCID: PMC10901801 DOI: 10.1038/s41598-024-55431-9] [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: 12/01/2023] [Accepted: 02/23/2024] [Indexed: 03/01/2024] Open
Abstract
Chameleons are well-known lizards with unique morphology and physiology, but their sex determination has remained poorly studied. Madagascan chameleons of the genus Furcifer have cytogenetically distinct Z and W sex chromosomes and occasionally Z1Z1Z2Z2/Z1Z2W multiple neo-sex chromosomes. To identify the gene content of their sex chromosomes, we microdissected and sequenced the sex chromosomes of F. oustaleti (ZZ/ZW) and F. pardalis (Z1Z1Z2Z2/Z1Z2W). In addition, we sequenced the genomes of a male and a female of F. lateralis (ZZ/ZW) and F. pardalis and performed a comparative coverage analysis between the sexes. Despite the notable heteromorphy and distinctiveness in heterochromatin content, the Z and W sex chromosomes share approximately 90% of their gene content. This finding demonstrates poor correlation of the degree of differentiation of sex chromosomes at the cytogenetic and gene level. The test of homology based on the comparison of gene copy number variation revealed that female heterogamety with differentiated sex chromosomes remained stable in the genus Furcifer for at least 20 million years. These chameleons co-opted for the role of sex chromosomes the same genomic region as viviparous mammals, lacertids and geckos of the genus Paroedura, which makes these groups excellent model for studies of convergent and divergent evolution of sex chromosomes.
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Affiliation(s)
- Michail Rovatsos
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic.
| | - Sofia Mazzoleni
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Barbora Augstenová
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Marie Altmanová
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Liběchov, Czech Republic
| | | | - Frank Glaw
- Zoologische Staatssammlung München (ZSM-SNSB), Munich, Germany
| | - Antonio Sanchez
- Department of Experimental Biology, University of Jaén, Jaén, Spain
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
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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: 4] [Impact Index Per Article: 4.0] [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.
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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
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Mezzasalma M, Brunelli E, Odierna G, Guarino FM. Comparative cytogenetics of Hemorrhois hippocrepis and Malpolon monspessulanus highlights divergent karyotypes in Colubridae and Psammophiidae (Squamata: Serpentes). THE EUROPEAN ZOOLOGICAL JOURNAL 2023. [DOI: 10.1080/24750263.2023.2180547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023] Open
Affiliation(s)
- M. Mezzasalma
- Department of Biology, Ecology and Earth Science, University of Calabria, Rende, Italy
| | - E. Brunelli
- Department of Biology, Ecology and Earth Science, University of Calabria, Rende, Italy
| | - G. Odierna
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - F. M. Guarino
- Department of Biology, University of Naples Federico II, Naples, Italy
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9
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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. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.20.524006. [PMID: 37034614 PMCID: PMC10081179 DOI: 10.1101/2023.01.20.524006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
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 2012-2017. 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.
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Affiliation(s)
- Brendan J Pinto
- School of Life Sciences, Arizona State University, Tempe, AZ USA
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ USA
- Department of Zoology, Milwaukee Public Museum, Milwaukee, WI USA
| | - Tony Gamble
- Department of Zoology, Milwaukee Public Museum, Milwaukee, WI USA
- Department of Biological Sciences, Marquette University, Milwaukee WI USA
- Bell Museum of Natural History, University of Minnesota, St Paul, MN USA
| | - Chase H Smith
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Melissa A Wilson
- School of Life Sciences, Arizona State University, Tempe, AZ USA
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ USA
- Center for Mechanisms of Evolution, Biodesign Institute, Tempe, AZ USA
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10
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Dodge TO, Farquharson KA, Ford C, Cavanagh L, Schubert K, Schumer M, Belov K, Hogg CJ. Genomes of two Extinct-in-the-Wild reptiles from Christmas Island reveal distinct evolutionary histories and conservation insights. Mol Ecol Resour 2023. [PMID: 36872490 DOI: 10.1111/1755-0998.13780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 02/16/2023] [Accepted: 03/02/2023] [Indexed: 03/07/2023]
Abstract
Genomics can play important roles in biodiversity conservation, especially for Extinct-in-the-Wild species where genetic factors greatly influence risk of total extinction and probability of successful reintroductions. The Christmas Island blue-tailed skink (Cryptoblepharus egeriae) and Lister's gecko (Lepidodactylus listeri) are two endemic reptile species that went extinct in the wild shortly after the introduction of a predatory snake. After a decade of management, captive populations have expanded from 66 skinks and 43 geckos to several thousand individuals; however, little is known about patterns of genetic variation in these species. Here, we use PacBio HiFi long-read and Hi-C sequencing to generate highly contiguous reference genomes for both reptiles, including the XY chromosome pair in the skink. We then analyse patterns of genetic diversity to infer ancient demography and more recent histories of inbreeding. We observe high genome-wide heterozygosity in the skink (0.007 heterozygous sites per base-pair) and gecko (0.005), consistent with large historical population sizes. However, nearly 10% of the blue-tailed skink reference genome falls within long (>1 Mb) runs of homozygosity (ROH), resulting in homozygosity at all major histocompatibility complex (MHC) loci. In contrast, we detect a single ROH in Lister's gecko. We infer from the ROH lengths that related skinks may have established the captive populations. Despite a shared recent extinction in the wild, our results suggest important differences in these species' histories and implications for management. We show how reference genomes can contribute evolutionary and conservation insights, and we provide resources for future population-level and comparative genomic studies in reptiles.
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Affiliation(s)
- Tristram O Dodge
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Sydney, Sydney, New South Wales, Australia
- Department of Biology, Stanford University, Stanford, California, USA
- Australian-American Fulbright Commission, Deakin, Australian Capital Territory, Australia
| | - Katherine A Farquharson
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Claire Ford
- Taronga Conservation Society Australia, Mosman, New South Wales, Australia
| | - Lisa Cavanagh
- Taronga Conservation Society Australia, Mosman, New South Wales, Australia
| | | | - Molly Schumer
- Department of Biology, Stanford University, Stanford, California, USA
| | - Katherine Belov
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Carolyn J Hogg
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Sydney, Sydney, New South Wales, Australia
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11
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Cytogenetic Analysis of Seven Species of Gekkonid and Phyllodactylid Geckos. Genes (Basel) 2023; 14:genes14010178. [PMID: 36672918 PMCID: PMC9859368 DOI: 10.3390/genes14010178] [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: 11/28/2022] [Revised: 12/24/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Geckos (Gekkota), the species-rich clade of reptiles with more than 2200 currently recognized species, demonstrate a remarkable variability in diploid chromosome numbers (2n = 16-48) and mode of sex determination. However, only a small fraction of gekkotan species have been studied with cytogenetic methods. Here, we applied both conventional (karyotype reconstruction and C-banding) and molecular (fluorescence in situ hybridization with probes for rDNA loci and telomeric repeats) cytogenetic analyses in seven species of geckos, namely Blaesodactylus boivini, Chondrodactylus laevigatus, Gekko badenii, Gekko cf. lionotum, Hemidactylus sahgali, Homopholis wahlbergii (Gekkonidae) and Ptyodactylus togoensis (Phyllodactylidae), in order to provide further insights into the evolution of karyotypes in geckos. Our analysis revealed the presence of interstitial telomeric repeats in four species, but we were not able to conclude if they are remnants of previous chromosome rearrangements or were formed by an accumulation of telomeric-like satellite motifs. Even though sex chromosomes were previously identified in several species from the genera Hemidactylus and Gekko by cytogenetic and/or genomic methods, they were not detected by us in any examined species. Our examined species either have poorly differentiated sex chromosomes or, possibly, environmental sex determination. Future studies should explore the effect of temperature and conduct genome-wide analyses in order to identify the mode of sex determination in these species.
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12
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Pensabene E, Yurchenko A, Kratochvíl L, Rovatsos M. Madagascar Leaf-Tail Geckos ( Uroplatus spp.) Share Independently Evolved Differentiated ZZ/ZW Sex Chromosomes. Cells 2023; 12:cells12020260. [PMID: 36672195 PMCID: PMC9856856 DOI: 10.3390/cells12020260] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 01/10/2023] Open
Abstract
Geckos are an excellent group to study the evolution of sex determination, as they possess a remarkable variability ranging from a complete absence of sex chromosomes to highly differentiated sex chromosomes. We explored sex determination in the Madagascar leaf-tail geckos of the genus Uroplatus. The cytogenetic analyses revealed highly heterochromatic W chromosomes in all three examined species (Uroplatus henkeli, U. alluaudi, U. sikorae). The comparative gene coverage analysis between sexes in U. henkeli uncovered an extensive Z-specific region, with a gene content shared with the chicken chromosomes 8, 20, 26 and 28. The genomic region homologous to chicken chromosome 28 has been independently co-opted for the role of sex chromosomes in several vertebrate lineages, including monitors, beaded lizards and monotremes, perhaps because it contains the amh gene, whose homologs were repeatedly recruited as a sex-determining locus. We demonstrate that all tested species of leaf-tail geckos share homologous sex chromosomes despite the differences in shape and size of their W chromosomes, which are not homologous to the sex chromosomes of other closely related genera. The rather old (at least 40 million years), highly differentiated sex chromosomes of Uroplatus geckos can serve as a great system to study the convergence of sex chromosomes evolved from the same genomic region.
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13
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Identification of Iguania Ancestral Syntenic Blocks and Putative Sex Chromosomes in the Veiled Chameleon ( Chamaeleo calyptratus, Chamaeleonidae, Iguania). Int J Mol Sci 2022; 23:ijms232415838. [PMID: 36555478 PMCID: PMC9779593 DOI: 10.3390/ijms232415838] [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: 10/28/2022] [Revised: 12/09/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
The veiled chameleon (Chamaeleo calyptratus) is a typical member of the family Chamaeleonidae and a promising object for comparative cytogenetics and genomics. The karyotype of C. calyptratus differs from the putative ancestral chameleon karyotype (2n = 36) due to a smaller chromosome number (2n = 24) resulting from multiple chromosome fusions. The homomorphic sex chromosomes of an XX/XY system were described recently using male-specific RADseq markers. However, the chromosomal pair carrying these markers was not identified. Here we obtained chromosome-specific DNA libraries of C. calyptratus by chromosome flow sorting that were assigned by FISH and sequenced. Sequence comparison with three squamate reptiles reference genomes revealed the ancestral syntenic regions in the C. calyptratus chromosomes. We demonstrated that reducing the chromosome number in the C. calyptratus karyotype occurred through two fusions between microchromosomes and four fusions between micro-and macrochromosomes. PCR-assisted mapping of a previously described Y-specific marker indicates that chromosome 5 may be the sex chromosome pair. One of the chromosome 5 conserved synteny blocks shares homology with the ancestral pleurodont X chromosome, assuming parallelism in the evolution of sex chromosomes from two basal Iguania clades (pleurodonts and acrodonts). The comparative chromosome map produced here can serve as the foundation for future genome assembly of chameleons and vertebrate-wide comparative genomic studies.
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14
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Han W, Liu L, Wang J, Wei H, Li Y, Zhang L, Guo Z, Li Y, Liu T, Zeng Q, Xing Q, Shu Y, Wang T, Yang Y, Zhang M, Li R, Yu J, Pu Z, Lv J, Lian S, Hu J, Hu X, Bao Z, Bao L, Zhang L, Wang S. Ancient homomorphy of molluscan sex chromosomes sustained by reversible sex-biased genes and sex determiner translocation. Nat Ecol Evol 2022; 6:1891-1906. [PMID: 36280781 DOI: 10.1038/s41559-022-01898-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 09/05/2022] [Indexed: 12/15/2022]
Abstract
Contrary to classic theory prediction, sex-chromosome homomorphy is prevalent in the animal kingdom but it is unclear how ancient homomorphic sex chromosomes avoid chromosome-scale degeneration. Molluscs constitute the second largest, Precambrian-originated animal phylum and have ancient, uncharacterized homomorphic sex chromosomes. Here, we profile eight genomes of the bivalve mollusc family of Pectinidae in a phylogenetic context and show 350 million years sex-chromosome homomorphy, which is the oldest known sex-chromosome homomorphy in the animal kingdom, far exceeding the ages of well-known heteromorphic sex chromosomes such as 130-200 million years in mammals, birds and flies. The long-term undifferentiation of molluscan sex chromosomes is potentially sustained by the unexpected intertwined regulation of reversible sex-biased genes, together with the lack of sexual dimorphism and occasional sex chromosome turnover. The pleiotropic constraint of regulation of reversible sex-biased genes is widely present in ancient homomorphic sex chromosomes and might be resolved in heteromorphic sex chromosomes through gene duplication followed by subfunctionalization. The evolutionary dynamics of sex chromosomes suggest a mechanism for 'inheritance' turnover of sex-determining genes that is mediated by translocation of a sex-determining enhancer. On the basis of these findings, we propose an evolutionary model for the long-term preservation of homomorphic sex chromosomes.
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Affiliation(s)
- Wentao Han
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Liangjie Liu
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Jing Wang
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Huilan Wei
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yuli Li
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Lijing Zhang
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Zhenyi Guo
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yajuan Li
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Tian Liu
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Qifan Zeng
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya, China
| | - Qiang Xing
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Ya Shu
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Tong Wang
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yaxin Yang
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Meiwei Zhang
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Ruojiao Li
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Jiachen Yu
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Zhongqi Pu
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Jia Lv
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Shanshan Lian
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Jingjie Hu
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya, China
| | - Xiaoli Hu
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Zhenmin Bao
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya, China
| | - Lisui Bao
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China.
| | - Lingling Zhang
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
| | - Shi Wang
- Sars-Fang Centre & MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Oceanographic Institution, Ocean University of China, Sanya, China.
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15
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Rovatsos M, Galoyan E, Spangenberg V, Vassilieva A, Kratochvíl L. XX
/
XY
sex chromosomes in a blind lizard (Dibamidae): Towards understanding the evolution of sex determination in squamates. J Evol Biol 2022; 35:1791-1796. [DOI: 10.1111/jeb.14123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 07/11/2022] [Accepted: 08/08/2022] [Indexed: 12/05/2022]
Affiliation(s)
- Michail Rovatsos
- Department of Ecology, Faculty of Science Charles University in Prague Praha 2 Czech Republic
| | - Eduard Galoyan
- A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences Moscow Russia
- Joint Russian‐Vietnamese Tropical Research and Technological Centre Hanoi Vietnam
- Zoological museum of Moscow State University Moscow State Regional University Mytishchi Russia
| | - Victor Spangenberg
- Zoological museum of Moscow State University Moscow State Regional University Mytishchi Russia
- Vavilov Institute of General Genetics Russian Academy of Sciences Moscow Russia
- Moscow State Regional University Mytishchi Russia
| | - Anna Vassilieva
- A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences Moscow Russia
- Joint Russian‐Vietnamese Tropical Research and Technological Centre Hanoi Vietnam
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science Charles University in Prague Praha 2 Czech Republic
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16
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Ma W, Rovatsos M. Sex chromosome evolution: The remarkable diversity in the evolutionary rates and mechanisms. J Evol Biol 2022; 35:1581-1588. [DOI: 10.1111/jeb.14119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 12/03/2022]
Affiliation(s)
- Wen‐Juan Ma
- Department of Molecular Biosciences University of Kansas Lawrence Kansas USA
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17
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Meter B, Kratochvíl L, Kubička L, Starostová Z. Development of male-larger sexual size dimorphism in a lizard: IGF1 peak long after sexual maturity overlaps with pronounced growth in males. Front Physiol 2022; 13:917460. [PMID: 36035474 PMCID: PMC9399403 DOI: 10.3389/fphys.2022.917460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 07/01/2022] [Indexed: 11/13/2022] Open
Abstract
Squamate reptiles have been considered to be indeterminate growers for a long time. However, recent studies demonstrate that bone prolongation is stopped in many lizards by the closure of bone growth plates. This shift in the paradigm of lizard growth has important consequences for questions concerning the proximate causes of sexual size dimorphism. The traditional model of highly plastic and indeterminate growth would correspond more to a long-term action of a sex-specific growth regulator. On the other hand, determinate growth would be more consistent with a regulator acting in a sex-specific manner on the activity of bone growth plates operating during the phase when a dimorphism in size develops. We followed the growth of males and females of the male-larger Madagascar ground gecko (Paroedura picta) and monitored the activity of bone growth plates, gonad size, levels of steroids, expression of their receptors (AR, ESR1), and expression of genes from the insulin-like growth factor network (IGF1, IGF2, IGF1R, and IGF2R) in livers. Specifically, we measured gene expression before the onset of dimorphic growth, at the time when males have more active bone growth plates and sexual size dimorphism was clearly visible, and after a period of pronounced growth in both sexes. We found a significant spike in the expression of IGF1 in males around the time when dimorphism develops. This overexpression in males comes long after an increase in circulating testosterone levels and sexual maturation in males, and it might be suppressed by ovarian hormones in females. The results suggest that sexual size dimorphism in male-larger lizards can be caused by a positive effect of high levels of IGF1 on bone growth. The peak in IGF1 resembles the situation during the pubertal growth spurt in humans, but in lizards, it seems to be sex-specific and disconnected from sexual maturation.
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Affiliation(s)
- Brandon Meter
- Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czechia
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University in Prague, Prague, Czechia
- *Correspondence: Lukáš Kratochvíl,
| | - Lukáš Kubička
- Department of Ecology, Faculty of Science, Charles University in Prague, Prague, Czechia
| | - Zuzana Starostová
- Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czechia
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18
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Miura I, Shams F, Jeffries DL, Katsura Y, Mawaribuchi S, Perrin N, Ito M, Ogata M, Ezaz T. Identification of ancestral sex chromosomes in the frog Glandirana rugosa bearing XX-XY and ZZ-ZW sex-determining systems. Mol Ecol 2022; 31:3859-3870. [PMID: 35691011 DOI: 10.1111/mec.16551] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/03/2022] [Accepted: 05/24/2022] [Indexed: 11/30/2022]
Abstract
Sex chromosomes constantly exist in a dynamic state of evolution: rapid turnover and change of heterogametic sex during homomorphic state, and often stepping out to a heteromorphic state followed by chromosomal decaying. However, the forces driving these different trajectories of sex chromosome evolution are still unclear. The Japanese frog Glandirana rugosa is one taxon well suited to the study on these driving forces. The species has two different heteromorphic sex chromosome systems, XX-XY and ZZ-ZW, which are separated in different geographic populations. Both XX-XY and ZZ-ZW sex chromosomes are represented by chromosome 7 (2n = 26). Phylogenetically, these two systems arose via hybridization between two ancestral lineages of West Japan and East Japan populations, of which sex chromosomes are homomorphic in both sexes and to date have not yet been identified. Identification of the sex chromosomes will give us important insight into the mechanisms of sex chromosome evolution in this species. Here, we used a high-throughput genomic approach to identify the homomorphic XX-XY sex chromosomes in both ancestral populations. Sex-linked DNA markers of West Japan were aligned to chromosome 1, whereas those of East Japan were aligned to chromosome 3. These results reveal that at least two turnovers across three different sex chromosomes 1, 3 and 7 occurred during evolution of this species. This finding raises the possibility that cohabitation of the two different sex chromosomes from ancestral lineages induced turnover to another new one in their hybrids, involving transition of heterogametic sex and evolution from homomorphy to heteromorphy.
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Affiliation(s)
- Ikuo Miura
- Amphibian Research Center, Hiroshima University, Higashi-Hiroshima, Japan.,Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia
| | - Foyez Shams
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia
| | - Daniel Lee Jeffries
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Yukako Katsura
- Primate Research Institute, Kyoto University, Inuyama, Japan
| | - Shuuji Mawaribuchi
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Nicolas Perrin
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Michihiko Ito
- School of Science, Kitasato University, Sagamihara, Japan
| | - Mitsuaki Ogata
- Preservation and Research Center, City of Yokohama, Yokohama, Japan
| | - Tariq Ezaz
- Amphibian Research Center, Hiroshima University, Higashi-Hiroshima, Japan.,Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia
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19
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Keating SE, Greenbaum E, Johnson JD, Gamble T. Identification of a cis-sex chromosome transition in banded geckos (Coleonyx, Eublepharidae, Gekkota). J Evol Biol 2022; 35:1675-1682. [PMID: 35665979 DOI: 10.1111/jeb.14022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/13/2022] [Accepted: 04/28/2022] [Indexed: 12/24/2022]
Abstract
Sex-determination systems are highly variable amongst vertebrate groups, and the prevalence of genomic data has greatly expanded our knowledge of how diverse some groups truly are. Gecko lizards are known to possess a variety of sex-determination systems, and each new study increases our knowledge of this diversity. Here, we used RADseq to identify male-specific markers in the banded gecko Coleonyx brevis, indicating this species has a XX/XY sex-determination system. Furthermore, we show that these sex-linked regions are not homologous to the XX/XY sex chromosomes of two related Coleonyx species, C. elegans and C. mitratus, suggesting that a cis-sex chromosome turnover-a change in sex chromosomes without a concomitant change in heterogamety-has occurred within the genus. These findings demonstrate the utility of genome-scale data to uncover novel sex chromosomes and further highlight the diversity of gecko sex chromosomes.
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Affiliation(s)
- Shannon E Keating
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Eli Greenbaum
- Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, USA
| | - Jerry D Johnson
- Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, USA
| | - Tony Gamble
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA.,Milwaukee Public Museum, Milwaukee, Wisconsin, USA.,Bell Museum of Natural History, University of Minnesota, St. Paul, Minnesota, USA
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20
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Pinto BJ, Keating SE, Nielsen SV, Scantlebury DP, Daza JD, Gamble T. Chromosome-Level Genome Assembly Reveals Dynamic Sex Chromosomes in Neotropical Leaf-Litter Geckos (Sphaerodactylidae: Sphaerodactylus). J Hered 2022; 113:272-287. [PMID: 35363859 PMCID: PMC9270867 DOI: 10.1093/jhered/esac016] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 03/24/2022] [Indexed: 02/07/2023] Open
Abstract
Sex determination is a critical element of successful vertebrate development, suggesting that sex chromosome systems might be evolutionarily stable across lineages. For example, mammals and birds have maintained conserved sex chromosome systems over long evolutionary time periods. Other vertebrates, in contrast, have undergone frequent sex chromosome transitions, which is even more amazing considering we still know comparatively little across large swaths of their respective phylogenies. One reptile group in particular, the gecko lizards (infraorder Gekkota), shows an exceptional lability with regard to sex chromosome transitions and may possess the majority of transitions within squamates (lizards and snakes). However, detailed genomic and cytogenetic information about sex chromosomes is lacking for most gecko species, leaving large gaps in our understanding of the evolutionary processes at play. To address this, we assembled a chromosome-level genome for a gecko (Sphaerodactylidae: Sphaerodactylus) and used this assembly to search for sex chromosomes among six closely related species using a variety of genomic data, including whole-genome re-sequencing, RADseq, and RNAseq. Previous work has identified XY systems in two species of Sphaerodactylus geckos. We expand upon that work to identify between two and four sex chromosome cis-transitions (XY to a new XY) within the genus. Interestingly, we confirmed two different linkage groups as XY sex chromosome systems that were previously unknown to act as sex chromosomes in tetrapods (syntenic with Gallus chromosome 3 and Gallus chromosomes 18/30/33), further highlighting a unique and fascinating trend that most linkage groups have the potential to act as sex chromosomes in squamates.
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Affiliation(s)
- Brendan J Pinto
- Address correspondence to B. J. Pinto at the address above, or e-mail:
| | - Shannon E Keating
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
| | - Stuart V Nielsen
- Department of Biological Sciences, Louisiana State University in Shreveport, Shreveport, LA 71115, USA,Division of Herpetology, Florida Museum of Natural History, Gainesville, FL 32611, USA
| | | | - Juan D Daza
- Department of Biological Sciences, Sam Houston State University, Huntsville, TX 77340, USA
| | - Tony Gamble
- Milwaukee Public Museum, Milwaukee, WI 53233, USA,Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA,Bell Museum of Natural History, University of Minnesota, St Paul, MN 55455, USA
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21
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Bouffet-Halle A, Yang W, Gardner MG, Whiting MJ, Wapstra E, Uller T, While GM. Characterisation and cross-amplification of sex-specific genetic markers in Australasian Egerniinae lizards and their implications for understanding the evolution of sex determination and social complexity. AUST J ZOOL 2022. [DOI: 10.1071/zo21023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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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: 8] [Impact Index Per Article: 2.7] [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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23
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Singchat W, Panthum T, Ahmad SF, Baicharoen S, Muangmai N, Duengkae P, Griffin DK, Srikulnath K. Remnant of Unrelated Amniote Sex Chromosomal Linkage Sharing on the Same Chromosome in House Gecko Lizards, Providing a Better Understanding of the Ancestral Super-Sex Chromosome. Cells 2021; 10:cells10112969. [PMID: 34831192 PMCID: PMC8616239 DOI: 10.3390/cells10112969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 10/28/2021] [Indexed: 12/18/2022] Open
Abstract
Comparative chromosome maps investigating sex chromosomal linkage groups in amniotes and microsatellite repeat motifs of a male house gecko lizard (Hemidactylus frenatus, HFR) and a flat-tailed house gecko lizard (H. platyurus, HPL) of unknown sex were examined using 75 bacterial artificial chromosomes (BACs) from chicken and zebra finch genomes. No massive accumulations of microsatellite repeat motifs were found in either of the gecko lizards, but 10 out of 13 BACs mapped on HPL chromosomes were associated with other amniote sex chromosomes. Hybridization of the same BACs onto multiple different chromosome pairs suggested transitions to sex chromosomes across amniotes. No BAC hybridization signals were found on HFR chromosomes. However, HFR diverged from HPL about 30 million years ago, possibly due to intrachromosomal rearrangements occurring in the HFR lineage. By contrast, heterochromatin likely reshuffled patterns between HPL and HFR, as observed from C-positive heterochromatin distribution. Six out of ten BACs showed partial homology with squamate reptile chromosome 2 (SR2) and snake Z and/or W sex chromosomes. The gecko lizard showed shared unrelated sex chromosomal linkages-the remnants of a super-sex chromosome. A large ancestral super-sex chromosome showed a correlation between SR2 and snake W sex chromosomes.
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Affiliation(s)
- Worapong Singchat
- Animal Genomics and Bioresource Research Center (AGB Research Center), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand; (W.S.); (T.P.); (S.F.A.)
- Laboratory of Animal Cytogenetics and Comparative Genomics (ACCG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand;
| | - Thitipong Panthum
- Animal Genomics and Bioresource Research Center (AGB Research Center), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand; (W.S.); (T.P.); (S.F.A.)
- Laboratory of Animal Cytogenetics and Comparative Genomics (ACCG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand;
| | - Syed Farhan Ahmad
- Animal Genomics and Bioresource Research Center (AGB Research Center), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand; (W.S.); (T.P.); (S.F.A.)
- Laboratory of Animal Cytogenetics and Comparative Genomics (ACCG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand;
| | - Sudarath Baicharoen
- Bureau of Conservation and Research, Zoological Park Organization of Thailand, Bangkok 10300, Thailand;
| | - Narongrit Muangmai
- Department of Fishery Biology, Faculty of Fisheries, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand;
| | - Prateep Duengkae
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand;
| | | | - Kornsorn Srikulnath
- Animal Genomics and Bioresource Research Center (AGB Research Center), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand; (W.S.); (T.P.); (S.F.A.)
- Laboratory of Animal Cytogenetics and Comparative Genomics (ACCG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand;
- Amphibian Research Center, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8526, Japan
- Correspondence:
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24
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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: 39] [Impact Index Per Article: 13.0] [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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25
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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: 24] [Impact Index Per Article: 8.0] [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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26
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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: 28] [Impact Index Per Article: 9.3] [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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27
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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: 14] [Impact Index Per Article: 4.7] [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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28
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Kostmann A, Augstenová B, Frynta D, Kratochvíl L, Rovatsos M. Cytogenetically Elusive Sex Chromosomes in Scincoidean Lizards. Int J Mol Sci 2021; 22:ijms22168670. [PMID: 34445371 PMCID: PMC8395508 DOI: 10.3390/ijms22168670] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/08/2021] [Accepted: 08/09/2021] [Indexed: 01/11/2023] Open
Abstract
The lizards of the species-rich clade Scincoidea including cordylids, gerrhosaurids, skinks, and xantusiids, show an almost cosmopolitan geographical distribution and a remarkable ecological and morphological divergence. However, previous studies revealed limited variability in cytogenetic traits. The sex determination mode was revealed only in a handful of gerrhosaurid, skink, and xantusiid species, which demonstrated either ZZ/ZW or XX/XY sex chromosomes. In this study, we explored the karyotypes of six species of skinks, two species of cordylids, and one gerrhosaurid. We applied conventional and molecular cytogenetic methods, including C-banding, fluorescence in situ hybridization with probes specific for telomeric motifs and rDNA loci, and comparative genomic hybridization. The diploid chromosome numbers are rather conserved among these species, but the chromosome morphology, the presence of interstitial telomeric sequences, and the topology of rDNA loci vary significantly. Notably, XX/XY sex chromosomes were identified only in Tiliqua scincoides, where, in contrast to the X chromosome, the Y chromosome lacks accumulations of rDNA loci. We confirm that within the lizards of the scincoidean clade, sex chromosomes remained in a generally poor stage of differentiation.
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Affiliation(s)
- Alexander Kostmann
- Department of Ecology, Faculty of Science, Charles University, 12844 Prague, Czech Republic; (A.K.); (B.A.); (L.K.)
| | - Barbora Augstenová
- Department of Ecology, Faculty of Science, Charles University, 12844 Prague, Czech Republic; (A.K.); (B.A.); (L.K.)
| | - Daniel Frynta
- Department of Zoology, Faculty of Science, Charles University, 12844 Prague, Czech Republic;
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, 12844 Prague, Czech Republic; (A.K.); (B.A.); (L.K.)
| | - Michail Rovatsos
- Department of Ecology, Faculty of Science, Charles University, 12844 Prague, Czech Republic; (A.K.); (B.A.); (L.K.)
- Correspondence:
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29
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Kuhl H, Guiguen Y, Höhne C, Kreuz E, Du K, Klopp C, Lopez-Roques C, Yebra-Pimentel ES, Ciorpac M, Gessner J, Holostenco D, Kleiner W, Kohlmann K, Lamatsch DK, Prokopov D, Bestin A, Bonpunt E, Debeuf B, Haffray P, Morvezen R, Patrice P, Suciu R, Dirks R, Wuertz S, Kloas W, Schartl M, Stöck M. A 180 Myr-old female-specific genome region in sturgeon reveals the oldest known vertebrate sex determining system with undifferentiated sex chromosomes. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200089. [PMID: 34247507 PMCID: PMC8273502 DOI: 10.1098/rstb.2020.0089] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Several hypotheses explain the prevalence of undifferentiated sex chromosomes in poikilothermic vertebrates. Turnovers change the master sex determination gene, the sex chromosome or the sex determination system (e.g. XY to WZ). Jumping master genes stay main triggers but translocate to other chromosomes. Occasional recombination (e.g. in sex-reversed females) prevents sex chromosome degeneration. Recent research has uncovered conserved heteromorphic or even homomorphic sex chromosomes in several clades of non-avian and non-mammalian vertebrates. Sex determination in sturgeons (Acipenseridae) has been a long-standing basic biological question, linked to economical demands by the caviar-producing aquaculture. Here, we report the discovery of a sex-specific sequence from sterlet (Acipenser ruthenus). Using chromosome-scale assemblies and pool-sequencing, we first identified an approximately 16 kb female-specific region. We developed a PCR-genotyping test, yielding female-specific products in six species, spanning the entire phylogeny with the most divergent extant lineages (A. sturio, A. oxyrinchus versus A. ruthenus, Huso huso), stemming from an ancient tetraploidization. Similar results were obtained in two octoploid species (A. gueldenstaedtii, A. baerii). Conservation of a female-specific sequence for a long period, representing 180 Myr of sturgeon evolution, and across at least one polyploidization event, raises many interesting biological questions. We discuss a conserved undifferentiated sex chromosome system with a ZZ/ZW-mode of sex determination and potential alternatives. 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)
- Heiner Kuhl
- Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301 and 310, 12587 Berlin, Germany
| | | | - Christin Höhne
- Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301 and 310, 12587 Berlin, Germany
| | - Eva Kreuz
- Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301 and 310, 12587 Berlin, Germany
| | - Kang Du
- 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
| | - Christophe Klopp
- SIGENAE, Plate-forme Bio-informatique Genotoul, Mathématiques et Informatique Appliquées de Toulouse, INRAe, 31326 Castanet-Tolosan, France
| | | | | | - Mitica Ciorpac
- Danube Delta National Institute for Research and Development, Tulcea 820112, Romania.,Genetic Improvement Laboratory, Research Station for Cattle Breeding Dancu - Iasi (SCDCB Dancu), Academy of Agricultural and Forestry Sciences 'Gheorghe Ionescu-Sisesti', Iasi-Ungheni Street, No. 9, Holboca, Iași county 707252, Romania
| | - Jörn Gessner
- Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301 and 310, 12587 Berlin, Germany
| | - Daniela Holostenco
- Danube Delta National Institute for Research and Development, Tulcea 820112, Romania
| | - Wibke Kleiner
- Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301 and 310, 12587 Berlin, Germany
| | - Klaus Kohlmann
- Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301 and 310, 12587 Berlin, Germany
| | - Dunja K Lamatsch
- Research Department for Limnology, University of Innsbruck, A-5310 Mondsee, Austria
| | - Dmitry Prokopov
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Anastasia Bestin
- SYSAAF, Station INRAE-LPGP, Campus de Beaulieu, 35042 Rennes cedex, France
| | | | - Bastien Debeuf
- SCEA Sturgeon, 29 rue du Carillon, 17240 Saint Fort sur Gironde, France
| | - Pierrick Haffray
- SYSAAF, Station INRAE-LPGP, Campus de Beaulieu, 35042 Rennes cedex, France
| | - Romain Morvezen
- SYSAAF, Station INRAE-LPGP, Campus de Beaulieu, 35042 Rennes cedex, France
| | - Pierre Patrice
- SYSAAF, Station INRAE-LPGP, Campus de Beaulieu, 35042 Rennes cedex, France
| | - Radu Suciu
- Danube Delta National Institute for Research and Development, Tulcea 820112, Romania
| | - Ron Dirks
- Future Genomics Technologies B.V., Sylviusweg 74, 2333 BD, Leiden, The Netherlands
| | - Sven Wuertz
- Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301 and 310, 12587 Berlin, Germany
| | - Werner Kloas
- Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301 and 310, 12587 Berlin, Germany
| | - 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
| | - Matthias Stöck
- Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301 and 310, 12587 Berlin, Germany
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30
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Augstenová B, Pensabene E, Veselý M, Kratochvíl L, Rovatsos M. Are Geckos Special in Sex Determination? Independently Evolved Differentiated ZZ/ZW Sex Chromosomes in Carphodactylid Geckos. Genome Biol Evol 2021; 13:evab119. [PMID: 34051083 PMCID: PMC8290109 DOI: 10.1093/gbe/evab119] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2021] [Indexed: 12/20/2022] Open
Abstract
Amniotes possess astonishing variability in sex determination ranging from environmental sex determination (ESD) to genotypic sex determination (GSD) with highly differentiated sex chromosomes. Geckos are one of the few amniote groups with substantial variability in sex determination. What makes them special in this respect? We hypothesized that the extraordinary variability of sex determination in geckos can be explained by two alternatives: 1) unusual lability of sex determination, predicting that the current GSD systems were recently formed and are prone to turnovers; and 2) independent transitions from the ancestral ESD to later stable GSD, which assumes that geckos possessed ancestrally ESD, but once sex chromosomes emerged, they remain stable in the long term. Here, based on genomic data, we document that the differentiated ZZ/ZW sex chromosomes evolved within carphodactylid geckos independently from other gekkotan lineages and remained stable in the genera Nephrurus, Underwoodisaurus, and Saltuarius for at least 15 Myr and potentially up to 45 Myr. These results together with evidence for the stability of sex chromosomes in other gekkotan lineages support more our second hypothesis suggesting that geckos do not dramatically differ from the evolutionary transitions in sex determination observed in the majority of the amniote lineages.
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Affiliation(s)
- Barbora Augstenová
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Eleonora Pensabene
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Milan Veselý
- Department of Zoology, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Michail Rovatsos
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
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31
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Augstenová B, Pensabene E, Kratochvíl L, Rovatsos M. Cytogenetic Evidence for Sex Chromosomes and Karyotype Evolution in Anguimorphan Lizards. Cells 2021; 10:cells10071612. [PMID: 34203198 PMCID: PMC8304200 DOI: 10.3390/cells10071612] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/27/2022] Open
Abstract
Anguimorphan lizards are a morphologically variable group of squamate reptiles with a wide geographical distribution. In spite of their importance, they have been cytogenetically understudied. Here, we present the results of the cytogenetic examination of 23 species from five anguimorphan families (Anguidae, Helodermatidae, Shinisauridae, Varanidae and Xenosauridae). We applied both conventional (Giemsa staining and C-banding) and molecular cytogenetic methods (fluorescence in situ hybridization with probes for the telomeric motifs and rDNA loci, comparative genome hybridization), intending to describe the karyotypes of previously unstudied species, to uncover the sex determination mode, and to reveal the distribution of variability in cytogenetic characteristics among anguimorphan lizards. We documented that karyotypes are generally quite variable across anguimorphan lineages, with anguids being the most varying. However, the derived chromosome number of 2n = 40 exhibits a notable long-term evolutionary stasis in monitors. Differentiated ZZ/ZW sex chromosomes were documented in monitors and helodermatids, as well as in the anguids Abronia lythrochila, and preliminary also in Celestus warreni and Gerrhonotus liocephalus. Several other anguimorphan species have likely poorly differentiated sex chromosomes, which cannot be detected by the applied cytogenetic methods, although the presence of environmental sex determination cannot be excluded. In addition, we uncovered a rare case of spontaneous triploidy in a fully grown Varanus primordius.
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Lisachov A, Andreyushkova D, Davletshina G, Prokopov D, Romanenko S, Galkina S, Saifitdinova A, Simonov E, Borodin P, Trifonov V. Amplified Fragments of an Autosome-Borne Gene Constitute a Significant Component of the W Sex Chromosome of Eremias velox (Reptilia, Lacertidae). Genes (Basel) 2021; 12:779. [PMID: 34065205 PMCID: PMC8160951 DOI: 10.3390/genes12050779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/11/2021] [Accepted: 05/17/2021] [Indexed: 01/30/2023] Open
Abstract
Heteromorphic W and Y sex chromosomes often experience gene loss and heterochromatinization, which is frequently viewed as their "degeneration". However, the evolutionary trajectories of the heterochromosomes are in fact more complex since they may not only lose but also acquire new sequences. Previously, we found that the heterochromatic W chromosome of a lizard Eremias velox (Lacertidae) is decondensed and thus transcriptionally active during the lampbrush stage. To determine possible sources of this transcription, we sequenced DNA from a microdissected W chromosome sample and a total female DNA sample and analyzed the results of reference-based and de novo assembly. We found a new repetitive sequence, consisting of fragments of an autosomal protein-coding gene ATF7IP2, several SINE elements, and sequences of unknown origin. This repetitive element is distributed across the whole length of the W chromosome, except the centromeric region. Since it retained only 3 out of 10 original ATF7IP2 exons, it remains unclear whether it is able to produce a protein product. Subsequent studies are required to test the presence of this element in other species of Lacertidae and possible functionality. Our results provide further evidence for the view of W and Y chromosomes as not just "degraded" copies of Z and X chromosomes but independent genomic segments in which novel genetic elements may arise.
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Affiliation(s)
- Artem Lisachov
- Institute of Environmental and Agricultural Biology (X-BIO), University of Tyumen, Lenina str. 23, 625003 Tyumen, Russia;
- Institute of Cytology and Genetics SB RAS, Acad. Lavrentiev Ave. 10, 630090 Novosibirsk, Russia; (G.D.); (P.B.)
| | - Daria Andreyushkova
- Institute of Molecular and Cellular Biology SB RAS, Acad. Lavrentiev Ave. 8/2, 630090 Novosibirsk, Russia; (D.A.); (D.P.); (S.R.); (V.T.)
| | - Guzel Davletshina
- Institute of Cytology and Genetics SB RAS, Acad. Lavrentiev Ave. 10, 630090 Novosibirsk, Russia; (G.D.); (P.B.)
- Institute of Molecular and Cellular Biology SB RAS, Acad. Lavrentiev Ave. 8/2, 630090 Novosibirsk, Russia; (D.A.); (D.P.); (S.R.); (V.T.)
| | - Dmitry Prokopov
- Institute of Molecular and Cellular Biology SB RAS, Acad. Lavrentiev Ave. 8/2, 630090 Novosibirsk, Russia; (D.A.); (D.P.); (S.R.); (V.T.)
| | - Svetlana Romanenko
- Institute of Molecular and Cellular Biology SB RAS, Acad. Lavrentiev Ave. 8/2, 630090 Novosibirsk, Russia; (D.A.); (D.P.); (S.R.); (V.T.)
| | - Svetlana Galkina
- Department of Genetics and Biotechnology, Saint Petersburg State University, Universitetskaya Emb. 7–9, 199034 Saint Petersburg, Russia;
| | - Alsu Saifitdinova
- Department of Human and Animal Anatomy and Physiology, Herzen State Pedagogical University of Russia, Moyka Emb. 48, 191186 Saint Petersburg, Russia;
| | - Evgeniy Simonov
- Institute of Environmental and Agricultural Biology (X-BIO), University of Tyumen, Lenina str. 23, 625003 Tyumen, Russia;
| | - Pavel Borodin
- Institute of Cytology and Genetics SB RAS, Acad. Lavrentiev Ave. 10, 630090 Novosibirsk, Russia; (G.D.); (P.B.)
- Novosibirsk State University, Pirogova str. 3, 630090 Novosibirsk, Russia
| | - Vladimir Trifonov
- Institute of Molecular and Cellular Biology SB RAS, Acad. Lavrentiev Ave. 8/2, 630090 Novosibirsk, Russia; (D.A.); (D.P.); (S.R.); (V.T.)
- Novosibirsk State University, Pirogova str. 3, 630090 Novosibirsk, Russia
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Mazzoleni S, Němec P, Albrecht T, Lymberakis P, Kratochvíl L, Rovatsos M. Long-term stability of sex chromosome gene content allows accurate qPCR-based molecular sexing across birds. Mol Ecol Resour 2021; 21:2013-2021. [PMID: 33720488 DOI: 10.1111/1755-0998.13381] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/13/2021] [Accepted: 03/08/2021] [Indexed: 12/14/2022]
Abstract
Embryos, juveniles, and even adults of many bird species lack pronounced external sexually dimorphic characteristics. Accurate identification of sex is crucial for research (e.g., developmental, population, and evolutionary studies), management of wildlife species, and captive breeding programmes for both conservation and poultry. An accurate molecular sexing method applicable across the entire bird radiation is theoretically possible thanks to the long-term stability of their ZZ/ZW sex chromosomes, but current methods are not applicable in a wide range of bird lineages. Here, we developed a novel molecular sexing method based on the comparison of gene copy number variation by quantitative real-time PCR (qPCR) in conserved Z-specific genes (CHRNA6, DDX4, LPAR1, TMEM161B, VPS13A), i.e. genes linked to Z but absent from W chromosomes. We tested the method across three paleognath and 70 neognath species covering the avian phylogeny. In addition, we designed primers for four Z-specific genes (DOCK8, FUT10, PIGG and PSD3) for qPCR-based molecular sexing in three paleognath species. We have demonstrated that the genes DOCK8, FUT10, PIGG and PSD3 can identify sex in paleognath birds and the genes CHRNA6, DDX4, TMEM161B, and VPS13A can reveal sex in neognath birds. The gene LPAR1 can be used to accurately identify sex in both paleognath and neognath species. Along with outlining a novel method of practical importance for molecular sexing in birds, our study also documents in detail the conservation of sex chromosomes across the avian phylogeny.
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Affiliation(s)
- Sofia Mazzoleni
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Pavel Němec
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Tomáš Albrecht
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic.,Institute of Vertebrate Biology, Czech Academy of Sciences, Brno, Czech Republic
| | - Petros Lymberakis
- Natural History Museum of Crete, University of Crete, Irakleio, Greece
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Michail Rovatsos
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
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Ehl J, Altmanová M, Kratochvíl L. With or Without W? Molecular and Cytogenetic Markers are Not Sufficient for Identification of Environmentally-Induced Sex Reversal in the Bearded Dragon. Sex Dev 2021; 15:272-281. [PMID: 33756476 DOI: 10.1159/000514195] [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: 09/08/2020] [Accepted: 12/22/2020] [Indexed: 12/24/2022] Open
Abstract
Transitions from environmental sex determination (ESD) to genotypic sex determination (GSD) require an intermediate step of sex reversal, i.e., the production of individuals with a mismatch between the ancestral genotypic and the phenotypic sex. Among amniotes, the sole well-documented transition in this direction was shown in the laboratory in the central bearded dragon, Pogona vitticeps, where very high incubation temperatures led to the production of females with the male-typical (ZZ) genotype. These sex-reversed females then produced offspring whose sex depended on the incubation temperature. Sex-reversed animals identified by molecular and cytogenetic markers were also reported in the field, and their increasing incidence was speculated as a climate warming-driven transition in sex determination. We show that the molecular and cytogenetic markers normally sex-linked in P. vitticeps are also sex-linked in P. henrylawsoni and P. minor, which points to quite ancient sex chromosomes in this lineage. Nevertheless, we demonstrate, based on a crossing experiment with a male bearded dragon who possesses a mismatch between phenotypic sex and genotype, that the used cytogenetic and molecular markers might not be reliable for the identification of sex reversal. Sex reversal should not be considered as the only mechanism causing a mismatch between genetic sex-linked markers and phenotypic sex, which can emerge also by other processes, here most likely by a rare recombination between regions of sex chromosomes which are normally sex-linked. We warn that sex-linked, even apparently for a long evolutionary time, and sex-specific molecular and cytogenetic markers are not a reliable tool for the identification of sex-reversed individuals in a population and that sex reversal has to be verified by other approaches, particularly by observation of the sex ratio of the progeny.
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Affiliation(s)
- Jan Ehl
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Marie Altmanová
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia.,Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, Liběchov, Czechia
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia,
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35
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Charlesworth D. When and how do sex-linked regions become sex chromosomes? Evolution 2021; 75:569-581. [PMID: 33592115 DOI: 10.1111/evo.14196] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/02/2021] [Accepted: 02/05/2021] [Indexed: 12/22/2022]
Abstract
The attention given to heteromorphism and genetic degeneration of "classical sex chromosomes" (Y chromosomes in XY systems, and the W in ZW systems that were studied first and are best described) has perhaps created the impression that the absence of recombination between sex chromosomes is inevitable. I here argue that continued recombination is often to be expected, that absence of recombination is surprising and demands further study, and that the involvement of selection in reduced recombination is not yet well understood. Despite a long history of investigations of sex chromosome pairs, there is a need for more quantitative approaches to studying sex-linked regions. I describe a scheme to help understand the relationships between different properties of sex-linked regions. Specifically, I focus on their sizes (differentiating between small regions and extensive fully sex-linked ones), the times when they evolved, and their differentiation, and review studies using DNA sequencing in nonmodel organisms that are providing information about the processes causing these properties.
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Affiliation(s)
- Deborah Charlesworth
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, EH9 3JT, United Kingdom
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36
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Keating SE, Blumer M, Grismer LL, Lin A, Nielsen SV, Thura MK, Wood PL, Quah ESH, Gamble T. Sex Chromosome Turnover in Bent-Toed Geckos ( Cyrtodactylus). Genes (Basel) 2021; 12:genes12010116. [PMID: 33477871 PMCID: PMC7832896 DOI: 10.3390/genes12010116] [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: 12/31/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 12/29/2022] Open
Abstract
Lizards and snakes (squamates) are known for their varied sex determining systems, and gecko lizards are especially diverse, having evolved sex chromosomes independently multiple times. While sex chromosomes frequently turnover among gecko genera, intrageneric turnovers are known only from Gekko and Hemidactylus. Here, we used RADseq to identify sex-specific markers in two species of Burmese bent-toed geckos. We uncovered XX/XY sex chromosomes in Cyrtodactylus chaunghanakwaensis and ZZ/ZW sex chromosomes in Cyrtodactylus pharbaungensis. This is the third instance of intrageneric turnover of sex chromosomes in geckos. Additionally, Cyrtodactylus are closely related to another genus with intrageneric turnover, Hemidactylus. Together, these data suggest that sex chromosome turnover may be common in this clade, setting them apart as exceptionally diverse in a group already known for diverse sex determination systems.
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Affiliation(s)
- Shannon E. Keating
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA; (S.V.N.); (T.G.)
- Correspondence: ; Tel.: +1-414-288-6551
| | - Madison Blumer
- Keck Science Department, Scripps College, Claremont, CA 91711, USA;
| | - L. Lee Grismer
- Herpetology Laboratory, Department of Biology, La Sierra University, Riverside, CA 92515, USA;
| | - Aung Lin
- Fauna and Flora International, No (35), 3rd Floor, Shan Gone Condo, Myay Ni Gone Market Street, Sanchaung Township, Yangon 11111, Myanmar;
| | - Stuart V. Nielsen
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA; (S.V.N.); (T.G.)
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI 48128, USA
- Department of Herpetology, Florida Museum of Natural History, Gainesville, FL 31611, USA
| | - Myint Kyaw Thura
- Myanmar Environment Sustainable Conservation, Yangon 11181, Myanmar;
| | - Perry L. Wood
- Department of Biological Sciences and Museum of Natural History, Auburn University, Auburn, AL 36849, USA;
| | - Evan S. H. Quah
- Institute of Tropical Biodiversity and Sustainable Development, University Malaysia Terengganu, Kuala Nerus, Terengganu 21030, Malaysia;
| | - Tony Gamble
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA; (S.V.N.); (T.G.)
- Milwaukee Public Museum, 800 W. Wells St., Milwaukee, WI 53233, USA
- Bell Museum of Natural History, University of Minnesota, 2088 Larpenteur Ave. W., St. Paul, MN 55113, USA
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