The green anole, Anolis carolinensis (ACA), is the model reptile for a vast array of biological disciplines. It was the first nonavian reptile to have its genome fully sequenced. During the genome project, the XX/XY system of sex chromosomes homologous to chicken chromosome 15 (GGA15) was revealed, and 106 X-linked genes were identified. We selected 38 genes located on eight scaffolds in ACA and having orthologs located on GGA15, then tested their linkage to ACA X chromosome by using comparative quantitative fluorescent real-time polymerase chain reaction applied to male and female genomic DNA. All tested genes appeared to be X-specific and not present on the Y chromosome. Assuming that all genes located on these scaffolds should be localized to the ACA X chromosome, we more than doubled the number of known X-linked genes in ACA, from 106 to 250. While demonstrating that the gene content of chromosome X in ACA and GGA15 is largely conserved, we nevertheless showed that numerous interchromosomal rearrangements had occurred since the splitting of the chicken and anole evolutionary lineages. The presence of many ACA X-specific genes localized to distinct contigs indicates that the ACA Y chromosome should be highly degenerated, having lost a large amount of its original gene content during evolution. The identification of novel genes linked to the X chromosome and absent on the Y chromosome in the model lizard species contributes to ongoing research as to the evolution of sex determination in reptiles and provides important information for future comparative and functional genomics.

Department of Ecology Faculty of Science Charles University Prague Prague 128

Department of Ecology Faculty of Science Charles University Prague Prague 128 44 Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Liběchov 277 21 Czech Republic

Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Liběchov 277 21 Czech Republic

Zobrazit více v PubMed

Alföldi J., Di Palma F., Grabherr M., Williams C., Kong L., et al. , 2011.  The genome of the green anole lizard and a comparative analysis with birds and mammals. Nature 477: 587–591. PubMed PMC

Badenhorst D., Stanyon R., Engstrom T., Valenzuela N., 2013.  A ZZ/ZW microchromosome system in the spiny softshell turtle, Apalone spinifera, reveals an intriguing sex chromosome conservation in Trionychidae. Chromosome Res. 21: 137–147. PubMed

Bar-Yaacov D., Bouskila A., Mishmar D., 2013.  The first chameleon transcriptome: comparative genomic analysis of the OXPHOS system reveals loss of COX8 in Iguanian lizards. Genome Biol. Evol. 5: 1792–1799. PubMed PMC

Benson D. A., Cavanaugh M., Clark K., Karsch-Mizrachi I., Lipman D. J., et al. , 2013.  GenBank. Nucleic Acids Res. 41: D36–D42. PubMed PMC

Castiglia R., Flores-Villela O., Bezerra A. M., Muñoz A., Gornung E., 2013.  Pattern of chromosomal changes in “beta” Anolis (Norops group) (Squamata: Polychrotidae) depicted by an ancestral state analysis. Zool. Stud. 52: 60.

Castoe T. A., de Koning A. P. J., Hall K. T., Yokoyama K. D., Gu W., et al. , 2011.  Sequencing the genome of the Burmese python (Python molurus bivittatus) as a model for studying extreme adaptations in snakes. Genome Biol. 12: 406. PubMed PMC

Cawthon R. M., 2002.  Telomere measurement by quantitative PCR. Nucleic Acids Res. 30: e47. PubMed PMC

Dalla Valle L., Nardi A., Bonazza G., Zuccal C., Emera D., et al. , 2010.  Forty keratin-associated β-proteins (β-keratins) form the hard layers of scales, claws, and adhesive pads in the green anole lizard, Anolis carolinensis. J. Exp. Zool. B Mol. Dev. Evol. 314: 11–32. PubMed

Eckalbar W. L., Lasku E., Infante C. R., Elsey R. M., Markov G. J., et al. , 2012.  Somitogenesis in the anole lizard and alligator reveals evolutionary convergence and divergence in the amniote segmentation clock. Dev. Biol. 363: 308–319. PubMed

Eckalbar W. L., Hutchins E. D., Markov G. J., Allen A. N., Corneveaux J. J., et al. , 2013.  Genome reannotation of the lizard Anolis carolinensis based on 14 adult and embryonic deep transcriptomes. BMC Genomics 14: 49. PubMed PMC

Ezaz T., Quinn A. E., Miura I., Sarre S. D., Georges A., et al. , 2005.  The dragon lizard Pogona vitticeps has ZZ/ZW micro-sex chromosomes. Chromosome Res. 13: 763–776. PubMed

Ezaz T., Azad B., O’Meally D., Young M. J., Matsubara K., et al. , 2013.  Sequence and gene content of a large fragment of a lizard sex chromosome and evaluation of candidate sex differentiating gene R-spondin 1. BMC Genomics 14: 899. PubMed PMC

Ferguson-Smith M. A., Trifonov V., 2007.  Mammalian karyotype evolution. Nat. Rev. Genet. 8: 950–962. PubMed

Flicek P., Amode M. R., Barrell D., Beal K., Billis K., et al. , 2014.  Ensembl 2014. Nucleic Acids Res. 42: D749–D755. PubMed PMC

Fujita M. K., Edwards S. V., Ponting C. P., 2011.  The Anolis lizard genome: an amniote genome without isochores. Genome Biol. Evol. 3: 974–984. PubMed PMC

Gamble T., 2010.  A review of sex determining mechanisms in geckos (Gekkota: Squamata). Sex Dev. 4: 88–103. PubMed PMC

Gamble T., Zarkower D., 2014.  Identification of sex-specific molecular markers using restriction site-associated DNA sequencing. Mol. Ecol. Resour. 14: 902–913. PubMed

Gamble T., Geneva A. J., Glor R. E., Zarkower D., 2014.  Anolis sex chromosomes are derived from a single ancestral pair. Evolution 68: 1027–1041. PubMed PMC

Gautam M., Mathur A., Khan M. A., Majumdar S. S., Rai U., 2013.  Transcriptome analysis of spermatogenically regressed, recrudescent and active phase testis of seasonally breeding wall lizards Hemidactylus flaviviridis. PLoS One 8: e58276. PubMed PMC

Griffin D. K., Robertson L. B. W., Tempest H. G., Skinner B. M., 2007.  The evolution of the avian genome as revealed by comparative molecular cytogenetics. Cytogenet. Genome Res. 117: 64–77. PubMed

Handley L. L., Ceplitis H., Ellegren H., 2004.  Evolutionary strata on the chicken Z chromosome: implications for sex chromosome evolution. Genetics 167: 367–376. PubMed PMC

Johnson M. A., Wade J., 2010.  Behavioural display systems across nine Anolis lizard species: sexual dimorphisms in structure and function. Proc. Biol. Sci. 277: 1711–1719. PubMed PMC

Johnson M. A., Cohen R. E., Vandecar J. R., Wade J., 2011.  Relationships among reproductive morphology, behavior, and testosterone in a natural population of green anole lizards. Physiol. Behav. 104: 437–445. PubMed

Kolbe J. J., Revell L. J., Szekely B., Brodii E. D., III, Losos J. B., 2011.  Convergent evolution of phenotypic integration and its alignment with morphological diversification in Caribbean Anolis ecomorphs. Evolution 65: 3608–3624. PubMed

Koshiba-Takeuchi K., Mori A. D., Kaynak B. L., Cebra-Thomas J., Sukonnik T., et al. , 2009.  Reptilian heart development and the molecular basis of cardiac chamber evolution. Nature 461: 95–98. PubMed PMC

Lahn B. T., Page D. C., 1999.  Four evolutionary strata on the human X chromosome. Science 286: 964–967. PubMed

Lithgow P. E., O’Connor R., Smith D., Fonseka G., Al Mutery A., et al. , 2014.  Novel tools for characterising inter and intra chromosomal rearrangements in avian microchromosomes. Chromosome Res. 22: 85–97. PubMed

Losos J. B., 2009.  Lizards in an Evolutionary Tree: Ecology and Adaptive Radiation of Anoles. University of California Press, Berkeley.

Losos J. B., Jackman T. R., Larson A., de Quieroz K., Rodríguez-Schettino L., 1998.  Contingency and determinism in replicated adaptive radiations of island lizards. Science 279: 2115–2118. PubMed

Louis A., Muffato M., Roest Crollius H., 2013.  Genomicus: five genome browsers for comparative genomics in eukaryota. Nucleic Acids Res. 41: D700–D705. PubMed PMC

Mank J. E., Ellegren H., 2007.  Parallel divergence and degradation of the avian W sex chromosome. Trends Ecol. Evol. 22: 389–391. PubMed

Matsubara K., Tarui H., Toriba M., Yamada K., Nishida-Umehara C., et al. , 2006.  Evidence for different origin of sex chromosomes in snakes, birds, and mammals and step-wise differentiation of snake sex chromosomes. Proc. Natl. Acad. Sci. USA 103: 18190–18195. PubMed PMC

Matsuda Y., Nishida-Umehara C., Tarui H., Kuroiwa A., Yamada K., et al. , 2005.  Highly conserved linkage homology between birds and turtles: bird and turtle chromosomes are precise counterparts of each other. Chromosome Res. 13: 601–615. PubMed

Matthey R., 1931.  Chromosomes de reptiles. Sauriens, ophidiens, chéloniens. L’évolution de la formule chromosomiale chez les sauriens. Rev. Suisse Zool. 38: 117–186.

Miller H. C., Biggs P. J., Voelckel C., Nelson N. J., 2012.  De novo sequence assembly and characterisation of a partial transcriptome for an evolutionarily distinct reptile, the tuatara (Sphenodon punctatus). BMC Genomics 13: 439. PubMed PMC

Murphy B. F., Thompson M. B., 2011.  A review of the evolution of viviparity in squamate reptiles: the past, present and future role of molecular biology and genomics. J. Comp. Physiol. B 181: 575–594. PubMed

Nam K., Ellegren H., 2008.  The chicken (Gallus gallus) Z chromosome contains at least three nonlinear evolutionary strata. Genetics 180: 1131–1136. PubMed PMC

Nguyen P., Sýkorová M., Šíchová J., Kůta V., Dalíková M., et al. , 2013.  Neo-sex chromosomes and adaptive potential in tortricid pests. Proc. Natl. Acad. Sci. USA 110: 6931–6936. PubMed PMC

Novick P. A., Basta H., Floumanhaft M., McClure M. A., Boissinot S., 2009.  The evolutionary dynamics of autonomous non-LTR retrotransposons in the lizard Anolis carolinensis shows more similarity to fish than mammals. Mol. Biol. Evol. 26: 1811–1822. PubMed

Organ C. L., Janes D. E., 2008.  Evolution of sex chromosomes in Sauropsida. Integr. Comp. Biol. 48: 512–519. PubMed PMC

Piskurek O., Nishihara H., Okada N., 2009.  The evolution of two partner LINE/SINE families and a full-length chromodomain-containing Ty3/Gypsy LTR element in the first reptilian genome of Anolis carolinensis. Gene 441: 111–118. PubMed

Pokorná M., Kratochvíl L., 2009.  Phylogeny of sex-determining mechanisms in squamate reptiles: are sex chromosomes an evolutionary trap? Zool. J. Linn. Soc. 156: 168–183.

Pokorná M., Giovannotti M., Kratochvíl L., Kasai F., Trifonov V. A., et al. , 2011.  Strong conservation of the bird Z chromosome in reptilian genomes is revealed by comparative painting despite 275 million years divergence. Chromosoma 120: 455–468. PubMed

Pokorná M., Giovannotti M., Kratochvíl L., Caputo V., Olmo E., et al. , 2012.  Conservation of chromosomes syntenic with avian autosomes in squamate reptiles revealed by comparative chromosome painting. Chromosoma 121: 409–418. PubMed

Rovatsos M., Altmanová M., Pokorná M., Kratochvíl L., 2014a Conserved sex chromosomes across adaptively radiated Anolis lizards. Evolution 68: 2079–2085. PubMed

Rovatsos M., Pokorná M., Altmanová M., Kratochvíl L., 2014b Cretaceous park of sex determination: sex chromosomes are conserved across iguanas. Biol. Lett. 10: 20131093. PubMed PMC

Sarre S. D., Georges A., Quinn A., 2004.  The ends of a continuum: genetic and temperature-dependent sex determination in reptiles. BioEssays 26: 639–645. PubMed

Skinner B. M., Griffin D. K., 2012.  Intrachromosomal rearrangements in avian genome evolution: evidence for regions prone to breakpoints. Heredity 108: 37–41. PubMed PMC

Srikulnath K., Nishida C., Matsubara K., Uno Y., Thongpan A., et al. , 2009.  Karyotypic evolution in squamate reptiles: comparative gene mapping revealed highly conserved linkage homology between the butterfly lizard (Leiolepis reevesii rubritaeniata, Agamidae, Lacertilia) and the Japanese four-striped rat snake (Elaphe quadrivirgata, Colubridae, Serpentes). Chromosome Res. 17: 975–986. PubMed

Srikulnath K., Uno Y., Nishida C., Matsuda Y., 2013.  Karyotype evolution in monitor lizards: cross-species chromosome mapping of cDNA reveals highly conserved synteny and gene order in the Toxicofera clade. Chromosome Res. 21: 805–819. PubMed

St John J. A., Braun E. L., Isberg S. R., Miles L. G., Chong A. Y., et al. , 2012.  Sequencing three crocodilian genomes to illuminate the evolution of archosaurs and amniotes. Genome Biol. 13: 415. PubMed PMC

Uno Y., Nishida C., Tarui H., Ishishita S., Takagi C., et al. , 2012.  Inference of the protokaryotypes of amniotes and tetrapods and the evolutionary processes of microchromosomes from comparative gene mapping. PLoS One 7: e53027. PubMed PMC

Valenzuela N., Lance V. A., 2004.  Temperature Dependent Sex Determination in Vertebrates. Smithsonian Books, Washington, DC.

Veyrunes F., Waters P. D., Miethke P., Rens W., McMillan D., et al. , 2008.  Bird-like sex chromosomes of platypus imply recent origin of mammal sex chromosomes. Genome Res. 18: 965–973. PubMed PMC

Vicoso B., Emerson J. J., Zektser Y., Mahajan S., Bachtrog D., 2013.  Comparative sex chromosome genomics in snakes: differentiation, evolutionary strata, and lack of global dosage compensation. PLoS Biol. 11: e1001643. PubMed PMC

Viets B. E., Ewert M. A., Talent L. G., Nelson C. E., 1994.  Sex-determining mechanisms in squamate reptiles. J. Exp. Zool. 270: 45–56.

Völker M., Backström N., Skinner B. M., Langley E. J., Ellegren H., et al. , 2010.  Copy number variation, chromosome rearrangement, and their association with recombination during avian evolution. Genome Res. 20: 503–511. PubMed PMC

Vonk F. J., Casewell N. R., Henkel C. V., Heimberg A. M., Jansen H. J., et al. , 2013.  The king cobra genome reveals dynamic gene evolution and adaptation in the snake venom system. Proc. Natl. Acad. Sci. USA 110: 20651–20656. PubMed PMC

Wang Z., Pascual-Anaya J., Zadissa A., Li W., Niimura Y., et al. , 2013.  The draft genomes of soft-shell turtle and green sea turtle yield insights into the development and evolution of the turtle-specific body plan. Nat. Genet. 45: 701–706. PubMed PMC

Wiens J. J., Brandley M. C., Reeder T. W., 2006.  Why does a trait evolve multiple times within a clade? Repeated evolution of snakelike body form in squamate reptiles. Evolution 60: 123–141. PubMed

Wu Q., Wei Z., Yang Z., Wang T., Ren L., et al. , 2010.  Phylogeny, genomic organization and expression of lambda and kappa immunoglobulin light chain genes in a reptile, Anolis carolinensis. Dev. Comp. Immunol. 34: 579–589. PubMed

Wüster W., Peppin L., Pook C. E., Walker D. E., 2008.  A nesting of vipers: Phylogeny and historical biogeography of the Viperidae (Squamata: Serpentes). Mol. Phylogenet. Evol. 49: 445–459. PubMed

Ye J., Coulouris G., Zaretskaya I., Cutcutache I., Rozen S., et al. , 2012.  Primer-BLAST: a tool to design target-specific primers for polymerase chain reaction. BMC Bioinformatics 13: 134. PubMed PMC

Young M. J., O’Meally D., Sarre S. D., Georges A., Ezaz T., 2013.  Molecular cytogenetic map of the central bearded dragon, Pogona vitticeps (Squamata: Agamidae). Chromosome Res. 21: 361–374. PubMed

Are Geckos Special in Sex Determination? Independently Evolved Differentiated ZZ/ZW Sex Chromosomes in Carphodactylid Geckos

Poorly differentiated XX/XY sex chromosomes are widely shared across skink radiation

Independent Evolution of Sex Chromosomes in Eublepharid Geckos, A Lineage with Environmental and Genotypic Sex Determination

Escaping the evolutionary trap? Sex chromosome turnover in basilisks and related lizards (Corytophanidae: Squamata)

Conserved sex chromosomes and karyotype evolution in monitor lizards (Varanidae)

Little evidence for switches to environmental sex determination and turnover of sex chromosomes in lacertid lizards

Mammalian X homolog acts as sex chromosome in lacertid lizards

Evolutionary stability of sex chromosomes in snakes

Interstitial Telomeric Motifs in Squamate Reptiles: When the Exceptions Outnumber the Rule

Low rate of interchromosomal rearrangements during old radiation of gekkotan lizards (Squamata: Gekkota)