Poster Presentation Society for Molecular Biology and Evolution Conference 2016

Sea turtle embryos may be able to adapt to climate change through molecular responses to thermal stress (#369)

Jamie Tedeschi 1 , Jason Kennington 1 , Joseph Tomkins 1 , Oliver Berry 2 , Scott Whiting 3 , Mark Meekan 4
  1. Centre for Evolutionary Biology, University of Western Australia, Crawley, WA, Australia
  2. Oceans and Atmosphere Flagship, CSIRO, Floreat, WA, Australia
  3. Marine Science Program, Department of Parks and Wildlife, Kensington, WA, Australia
  4. Australian Institute of Marine Science, Crawley, WA, Australia

The capacity of species to respond adaptively to warming temperatures will be key to their survival in the Anthropocene. The embryos of egg-laying species such as sea turtles have limited behavioural means for avoiding high nest temperatures, and responses at the physiological level may be critical to coping with predicted global temperature increases. Using the loggerhead sea turtle (Caretta caretta) as a model, we used quantitative PCR to characterise variation in the expression response of heat shock genes (hsp60, hsp70, and hsp90; molecular chaperones involved in cellular stress response) to an acute non-lethal heat shock. We show significant variation in gene expression at the clutch and population levels for some, but not all hsp genes. Using pedigree information, we estimated heritabilities of the expression response of hsp genes to heat shock and demonstrated both maternal and additive genetic effects. This is the first evidence that the heat shock response is heritable in sea turtles and operates at the embryonic stage in any reptile. The presence of heritable variation in the expression of key thermotolerance genes is necessary for sea turtles to adapt at a molecular level to warming incubation environments.