Conquering the Frozen Frontier through Epigenetics: Red-Eared Slider Turtles’ Battle for Survival in Ice-Encased Ponds
Abstract:
Red-eared slider turtles (Trachemys scripta) have a remarkable adaptation that allows them to withstand prolonged periods of anoxia in ice-locked ponds during Canadian winters. Their survival is characterized by metabolic rate depression (MRD) which prioritizes energy to pro-survival pathways and minimalizes energy expensive pathways by suppressing gene expression. Amongst many biochemical processes, epigenetic histone lysine acetylation and methylation play crucial roles in regulating gene expression during MRD, but they remain uncharacterized in skeletal muscle of red-eared slider turtles. This thesis presents evidence of epigenetic controls on histone lysine acetylation and methylation in red and white skeletal muscle tissue of the red-eared slider turtles. Many enzymes and histone marks showed trends that were consistent with downregulation of gene expression during anoxia. Other proteins and histone marks exhibited unexpected trends in relative protein expression, changes that were attributed either to non-histone target roles or pro-survival pathways needed by the turtle to survive.