Meeting Abstract
Insects exposed to low temperatures typically enter a state of paralysis known as chill coma, and individuals that do not die from the cold can recover from this state after an amount of time known as Chill Coma Recovery Time (CCRT). Both low temperature injury and prolonged CCRT have been causally associated with progressive hyperkalemia in the cold. In a Fluctuating Thermal Regime (FTR), warm recovery periods interrupt periods of low temperature exposure and enhance low temperature survival. In this study, we examine whether longer recovery periods improve survival and speed up CCRT of female D. melanogaster, and if so, whether this effect can be attributed to superior restoration of K+ balance during these warm periods. Flies subjected to a single prolonged cold stress, as well as flies that experienced multiple cold exposures with shorter warm periods, had higher mortalities and higher CCRTs than flies that stayed warm for longer between cold bouts. Thus, a FTR with longer warm periods enhances survival and reduces CCRT, but whether this is directly or indirectly a result of an improved ability to restore extracellular K+ balance during warm periods is unknown. We thus tested this hypothesis by measuring hemolymph K+ concentrations in female flies under the same conditions.
