Meeting Abstract

29.1  Wednesday, Jan. 5  The impacts of repeated cold exposure in insects SINCLAIR, BJ*; MARSHALL, KE; ZHANG, J; The University of Western Ontario bsincla7@uwo.ca

In nature, insects are exposed to repeated bouts of environmental stress, although laboratory experiments seldom reflect this. We have been using insect cold tolerance as a model to explore the impacts of repeated stress in both chill-susceptible Drosophila melanogaster and freeze-tolerant arctiid caterpillars and goldenrod gall flies. There are significant impacts of repeated cold exposure, independent of duration of cold exposure, in all species, and we quantify these as fitness effects, as well as by examining the impact of repeated freezing on tissue damage. In D. melanogaster, we further explore the response to repeated cold exposure by examining gene expression patterns using whole-genome microarrays. A variety of groups of genes are differentially upregulated in response to cold, including the turandot group, which is also associated with immune function. Further experiments on caterpillars indicate that repeated freezing appears to enhance the immune response.