Poster Presentation Society for Molecular Biology and Evolution Conference 2016

Biogeography of sex reversal and the effects of climate on sex determination (#570)

Clare Holleley 1 2 , Stephen Sarre 2 , Arthur Georges 2
  1. CSIRO, Canberra, ACT, Australia
  2. University of Canberra, Canberra, ACT, Australia

Recent advances have demonstrated that reptiles can rapidly switch from a sex determination mode that is predominantly genetic (using sex chromosomes) to a system where sex is determined by egg incubation temperature (without sex chromosomes)1. This is achieved through the occurrence of sex reversal in wild populations – where chromosomal males are feminised at high incubation temperature. Sex reversal can rapidly trigger the evolution of new sex determining modes, by facilitating the loss of the W sex chromosome and thus a transition from genetic sex determination to temperature dependent sex determination. Here we use a continental-scale data set to characterize the genotypic and phenotypic sex of bearded dragon populations (Pogona vitticeps) and identify populations with sex reversal events. We then explore whether these events occur in locations experiencing a rapid increase in diurnal temperature range, an increase in mean temperatures, or record-breaking warming events. We also explore the possibility of using specimens from Australia’s National collections to track temporal changes in the rates of sex reversal over the last century.

  1. Holleley CE, O'Meally D, Sarre SD, Graves JAM, Ezaz T, Matsubara K, Azad B, Zhang X, Georges A. 2015. Nature 523 (7558), 79-82