Meeting Abstract
Vertebrates with temperature-dependent sex determination (TSD), a sex determining mechanism which relies on incubation temperature to determine the sex of developing embryos, are especially threatened by the impending changes in climate. Previous studies have suggested modes of inheritance in this system that may provide opportunities for these species to adapt to climate change, however a complete molecular mechanism remains elusive. Epigenetic studies have the potential to unlock crucial information previously cryptic in traditional genetic studies. DNA methylation is well-known for its dynamic ability to silence genes, and evidence is accumulating for its role in determining sex in TSD systems. Using the painted turtle, Chrysemys picta, as a model for TSD, this study investigated the heritability of DNA methylation and its ability to predispose individuals to a particular sex by observing the methylome at different life stages of related individuals. Clutches collected in the field were incubated at a temperature to produce both sexes. The adrenal-kidney-gonad complex was harvested from a subset of early-stage embryos and gonads from the remaining hatchlings were collected to compare basal and hatching methylation. These were also compared to the methylome of their respective mother to determine inheritance. Epigenetic inheritance has the potential to mediate the effects of climate change on the population dynamics of species with TSD. This can be leveraged by global conservation efforts, as well as evolutionary and ecological studies, as climate change threatens to extinguish reptiles with TSD.
