Letter | Published:

Sex reversal triggers the rapid transition from genetic to temperature-dependent sex

Nature volume 523, pages 7982 (02 July 2015) | Download Citation


Sex determination in animals is amazingly plastic. Vertebrates display contrasting strategies ranging from complete genetic control of sex (genotypic sex determination) to environmentally determined sex (for example, temperature-dependent sex determination)1. Phylogenetic analyses suggest frequent evolutionary transitions between genotypic and temperature-dependent sex determination in environmentally sensitive lineages, including reptiles2. These transitions are thought to involve a genotypic system becoming sensitive to temperature, with sex determined by gene–environment interactions3. Most mechanistic models of transitions invoke a role for sex reversal3,4,5. Sex reversal has not yet been demonstrated in nature for any amniote, although it occurs in fish6 and rarely in amphibians7,8. Here we make the first report of reptile sex reversal in the wild, in the Australian bearded dragon (Pogona vitticeps), and use sex-reversed animals to experimentally induce a rapid transition from genotypic to temperature-dependent sex determination. Controlled mating of normal males to sex-reversed females produces viable and fertile offspring whose phenotypic sex is determined solely by temperature (temperature-dependent sex determination). The W sex chromosome is eliminated from this lineage in the first generation. The instantaneous creation of a lineage of ZZ temperature-sensitive animals reveals a novel, climate-induced pathway for the rapid transition between genetic and temperature-dependent sex determination, and adds to concern about adaptation to rapid global climate change.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


Primary accessions


Data deposits

The W chromosome sequence has been deposited in GenBank under accession number KM508988.


  1. 1.

    , & The ends of a continuum: genetic and temperature-dependent sex determination in reptiles. Bioessays 26, 639–645 (2004)

  2. 2.

    , & Transitions between sex-determining systems in reptiles and amphibians. Annu. Rev. Genom. Hum. Genet. 12, 391–406 (2011)

  3. 3.

    Evolution of environmental sex determination from genotypic sex determination. Heredity 47, 173–184 (1981)

  4. 4.

    , , , & Evolutionary transitions between mechanisms of sex determination in vertebrates. Biol. Lett. 7, 443–448 (2011)

  5. 5.

    , , & Novel evolutionary pathways of sex-determining mechanisms. J. Evol. Biol. 26, 2544–2557 (2013)

  6. 6.

    & Sex control and sex reversal in fish under natural conditions. Fish Physiol. 9, 171–222 (1983)

  7. 7.

    , & Sex reversal and primary sex ratios in the common frog (Rana temporaria). Mol. Ecol. 19, 1763–1773 (2010)

  8. 8.

    Sex chromosome differentiation in the Japanese brown frog, Rana japonica. I. Sex-related heteromorphism of the distribution pattern of constitutive heterochromatin in chromosome no. 4 of the Wakuya population. Zool. Sci. 11, 797–806 (1994)

  9. 9.

    et al. Sex determination: why so many ways of doing it? PLoS Biol. 12, e1001899 (2014)

  10. 10.

    , & Co-occurrence of multiple, supposedly incompatible modes of sex determination in a lizard population. Ecol. Lett. 5, 486–489 (2002)

  11. 11.

    , , , & Genetic evidence for co-occurrence of chromosomal and thermal sex-determining systems in a lizard. Biol. Lett. 4, 176–178 (2008)

  12. 12.

    et al. Temperature sex reversal implies sex gene dosage in a reptile. Science 316, 411 (2007)

  13. 13.

    , & Predetermination of sexual fate in a turtle with temperature-dependent sex determination. Dev. Biol. 386, 264–271 (2014)

  14. 14.

    et al. Identification of sex chromosomes by means of comparative genomic hybridization in a lizard, Eremias multiocellata. Zool. Sci. 32, 151–156 (2015)

  15. 15.

    et al. The dragon lizard Pogona vitticeps has ZZ/ZW micro-sex chromosomes. Chromosome Res. 13, 763–776 (2005)

  16. 16.

    , , , & Extension, single-locus conversion and physical mapping of sex chromosome sequences identify the Z microchromosome and pseudo-autosomal region in a dragon lizard, Pogona vitticeps. Heredity 104, 410–417 (2010)

  17. 17.

    et al. Sequence and gene content of a large fragment of a lizard sex chromosome and evaluation of candidate sex differentiating gene R-spondin 1. BMC Genom. 14, 899 (2013)

  18. 18.

    et al. Facultative parthenogenesis discovered in wild vertebrates. Biol. Lett. 8, 983–985 (2012)

  19. 19.

    , , , & Evidence for viable, non-clonal but fatherless boa constrictors. Biol. Lett. 7, 253–256 (2011)

  20. 20.

    et al. Parthenogenesis in Komodo dragons. Nature 444, 1021–1022 (2006)

  21. 21.

    & When is sex environmentally determined? Nature 266, 828–830 (1977)

  22. 22.

    & The adaptive significance of temperature-dependent sex determination in a reptile. Nature 451, 566–568 (2008)

  23. 23.

    & The adaptive significance of temperature-dependent sex determination: experimental tests with a short lived lizard. Evolution 59, 2209–2221 (2005)

  24. 24.

    & Effective heritability of targets of sex-ratio selection under environmental sex determination. J. Evol. Biol. 24, 784–794 (2011)

  25. 25.

    et al. XY females do better than the XX in the african pygmy mouse, Mus minutoides. Evolution 68, 2119–2127 (2014)

  26. 26.

    Evolution of Sex Determining Mechanisms (Benjamin-Cummings, 1983)

  27. 27.

    et al. Erosion of lizard diversity by climate change and altered thermal niches. Science 328, 894–899 (2010)

  28. 28.

    & Climate change and evolutionary adaptation. Nature 470, 479–485 (2011)

  29. 29.

    , , & Under what conditions do climate-driven sex ratios enhance versus diminish population persistence? Ecol. Evol. 4, 4522–4533 (2014)

  30. 30.

    & Transitional range of temperature, pivotal temperatures and thermosensitive stages for sex determination in reptiles. Amphib.-Reptil. 12, 169–179 (1991)

  31. 31.

    A harmless technique for sexing hatchling lizards. Herpetol. Rev. 27, 71–72 (1996)

  32. 32.

    Hemipenal transillumination as a sexing technique in varanids. Biawak 3, 26–29 (2009)

  33. 33.

    et al. A simple non-invasive protocol to establish primary cell lines from tail and toe explants for cytogenetic studies in Australian dragon lizards (Squamata: Agamidae). Cytotechnology 58, 135–139 (2008)

  34. 34.

    , , , & Molecular cytogenetic map of the central bearded dragon, Pogona vitticeps (Squamata: Agamidae). Chromosome Res. 21, 361–374 (2013)

  35. 35.

    A simple technique for demonstrating centromeric heterochromatin. Exp. Cell Res. 75, 304–306 (1972)

  36. 36.

    et al. Highly differentiated ZW sex microchromosomes in the Australian Varanus species evolved through rapid amplification of repetitive sequences. PLoS ONE 9, e95226 (2014)

  37. 37.

    , , , & Differentiation of the XY sex chromosomes in the fish Hoplias malabaricus (Characiformes, Erythrinidae): unusual accumulation of repetitive sequences on the X chromosome. Sex Dev. 4, 176–185 (2010)

  38. 38.

    et al. Genome-wide association mapping of root traits in a japonica rice panel. PLoS ONE 8, e78037 (2013)

  39. 39.

    , & Development of DArT marker platforms and genetic diversity assessment of the U.S. collection of the new oilseed crop lesquerella and related species. PLoS ONE 8, e64062 (2013)

  40. 40.

    et al. Diversity arrays technology: a generic genome profiling technology on open platforms. Methods Mol. Biol. 888, 67–89 (2012)

  41. 41.

    et al. Genome-wide delineation of natural variation for pod shatter resistance in Brassica napus. PLoS ONE 9, e101673 (2014)

Download references


We thank the following persons and institutions: W. Ruscoe and J. Richardson (animal husbandry); A. Quinn, M. Young and J. Richardson (field collections); A. Kilian and Diversity Arrays Technology (SNP genotyping); A. Livernois (sequencing assistance); B. Gruber and N. Garlapati (geographic information system); A. T. Adamack (modelling advice); A. Dobos and P. E. Geertz (graphic design); J. Deakin, R. Thompson and the Kioloa Science Writers Workshop (revisions of the manuscript). We particularly thank reviewer J. J. Bull for suggesting the modelling approach in Extended Data Fig. 4. Funding was from Australian Research Council Discovery Grant DP110104377 to A.G. and T.E. This research was conducted under appropriate approvals from the Victorian, New South Wales and Queensland authorities, and with approvals from the Animal Ethics Committee of the University of Canberra.

Author information

Author notes

    • Kazumi Matsubara
    •  & Bhumika Azad

    Present addresses: Research Center for Aquatic Genomics, National Research Institute of Fisheries Science, Fisheries Research Agency, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa 236-8648, Japan (K.M.); John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2601, Australia (B.A.).


  1. Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory 2601, Australia

    • Clare E. Holleley
    • , Denis O'Meally
    • , Stephen D. Sarre
    • , Jennifer A. Marshall Graves
    • , Tariq Ezaz
    • , Kazumi Matsubara
    • , Bhumika Azad
    • , Xiuwen Zhang
    •  & Arthur Georges
  2. School of Life Science, La Trobe University, Melbourne, Victoria 3086, Australia

    • Jennifer A. Marshall Graves


  1. Search for Clare E. Holleley in:

  2. Search for Denis O'Meally in:

  3. Search for Stephen D. Sarre in:

  4. Search for Jennifer A. Marshall Graves in:

  5. Search for Tariq Ezaz in:

  6. Search for Kazumi Matsubara in:

  7. Search for Bhumika Azad in:

  8. Search for Xiuwen Zhang in:

  9. Search for Arthur Georges in:


C.E.H. and A.G. designed the study. C.E.H. conducted breeding experiments, egg incubations, parentage SNP analysis and prepared figures. D.O'M. collected the animals from the field. C.E.H. and X.Z. conducted the molecular sex testing. B.A. and K.M. undertook the cytogenetic analysis and prepared extended data figures, under the supervision of T.E. A.G. and C.E.H. undertook the statistical analyses and A.G. conducted the modelling of ZW genotype frequency with temperature. All authors contributed to writing the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Clare E. Holleley or Arthur Georges.

Extended data

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    This file contains Supplementary Tables 1-4.

Excel files

  1. 1.

    Supplementary data

    This file contains the source data used to make Supplementary Table 1.

About this article

Publication history






Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.