Meeting Abstract
The ability to rapidly respond to low temperature is critical for insects and other ectotherms living in thermally variable environments. The gene Frost (Fst) and members of the Heat Shock Protein (HSP) family are rapidly upregulated following cold shock in Drosophila and other insects, and knockdown experiments have demonstrated these genes are essential for survival following cold stress. However, there is conflicting evidence regarding the role of Fst in cold tolerance, and the extent to which variation in Fst and HSP expression corresponds with genetic variation in cold tolerance is unknown. Here we tested the hypothesis that genotypic variation in cold tolerance is associated with variation in baseline expression and induction of these genes. We measured five common cold tolerance traits across 12 isogenic lines from the Drosophila Genetic Reference, and all of these traits showed significant genetic variation. However, while some lines performed well in all or most measures of cold tolerance, in general cold tolerance traits were not correlated across the lines, suggesting each trait may have distinct underlying mechanisms. Gene expression analyses of Fst and HSPs are underway, with initial results from a single genotype showing upregulation of both genes following cold shock. Ultimately, our results indicate the extent to which cold tolerance traits are genetically correlated and enhance our understanding of the molecular underpinnings that drive natural variation in cold tolerance.
