Meeting Abstract
The physiology of ectotherms must be able to function across a wide range of environmental temperatures, particularly in thermally variable habitats. When external temperatures are temporally correlated, earlier thermal experiences can lead to a beneficial acclimation response that enhances robustness to future thermal conditions. In Drosophila melanogaster, temperatures experienced during larval development can lead to shifts in critical thermal minima (CTmin) of ~1.5°C, and critical thermal maxima (CTmax) of ~0.5°C. Although these whole-body effects are well-described, it is unclear how developmental acclimation produces enhanced thermal tolerance, particularly in the central nervous system, whose failure operationally defines critical thermal limits. We investigated the effect of developmental acclimation on brain gene expression by comparing brain transcriptomic profiles of D. melanogaster that were reared from egg through pupation at 18°C, 25°C, or 30°C and then held at 25°C for two days as adults. Developmental temperature impacted a small proportion of genes, with a larger number showing a response to cool rearing temperatures (23) than warm temperatures (2) when each were compared to the control of 25°C. Among these, several were associated with thermal protective functions, including the heat shock response, calcium ion regulation, and phospholipid metabolism. These results suggest that the adult brain may be primed by gene-regulatory changes that are set during development to prophylactically protect against thermally-induced neuronal failure as an adult.
