Differential expression in heat resistance selected adult female Drosophila melanogaster

gene expression was measured in five independent heat resistance selected replicate lines and five control lines. The genetic architecture underlying heat resistance remains partly unclear despite the well documented involvement of heat shock proteins (Hsps). It was previously shown that factors besides Hsps are likely to play an important role for heat resistance. In this study, gene expression arrays were used to make replicate measurements of gene expression before and up to 64h after a mild heat stress treatment, in flies selected for heat resistance and unselected control flies, to identify genes differentially expressed in heat resistance selected flies. We found 108 genes upregulated and 10 downregulated using the Affymetrix gene expression platform. Among the upregulated genes, a substantial number are involved in the phototransduction process. Another group of genes upregulated in selected flies is characterized by also responding to heat shock treatment several hours after peak induction of known Hsps revert to non-stress levels. These findings suggest phototransduction genes to be critically involved in heat resistance, and support a role for components of the phototransduction process in stress sensing mechanisms. In addition the results suggest yet uncharacterized genes responding to heat stress several hours after treatment to be involved in heat stress resistance. These findings mark an important increase in the understanding of heat resistance. Keywords: control versus selected gene expression was measured in five independent heat resistance selected replicate lines and five control lines