Cold adaptation of insects: the role of shock proteins from Hsp family.

Heat shock proteins (Hsps) form evolutionarily conserved group of proteins that are best known for their unique function in repair of miss folded proteins that would otherwise aggregate in cells during stress conditions. The most extensively studied is the inducible Hsp70. Using 3rd instar larvae of transgene mutant of fruit fly, Drosophila melanogaster that lacks all copies of hsp70 gene, we assessed: 1) whether the absence of this gene is deleterious for larvae in their capacity to survive cold stress; and 2) whether any other gene from Hsps family may compensate for the loss of hsp70. We found that 1) survival of cold stress is not altered in Hsp- larvae when compared to wild type Hsp+ larvae; 2) there is no other gene of Hsps family that would compensate for the loss of hsp70 at the level of transcription. Our ongoing effort is focusing on analysis of cold stress response at the protein level