The influence of natural variation at the foraging gene on thermotolerance in adult Drosophila in a narrow temperature range

Poikilothermic organisms such as insects have mechanisms to protect neural function under high temperature stress. Natural variation at the foraging ( for ) locus of the fruit fly, Drosophila melanogaster, encoding a cGMP-dependent protein kinase (PKG), influences neural thermotolerance in Drosophila larvae. The current study re-examines thermotolerance of adult flies to account for inconsistencies in the documented role of for during hyperthermia. We found that adult for R ( rover ) flies with high PKG activity were incapacitated faster under hyperthermic conditions of 39°C compared to their lower PKG activity counterparts for s and for s2 ( sitters ), but not at higher temperatures. This indicates that lowered PKG activity promotes tolerance to heat stress, and that the for gene influences thermotolerance for a narrow range of temperatures in adult flies.