PARENT SESSION
Oral Session # 57: Evolutionary Ecology II: Animal.
Presiding: S Juliano
Wednesday, August 6. 1:30 PM to 5:00 PM, SITCC Meeting Room 201.

Gene expression patterns underlying host shifts in Drosophila melanogaster.

Carsten, L^*,1, Watts, T¹, Bosco, G¹, Markow, T¹, ¹ University of Arizona, Tucson, AZ

ABSTRACT- The ability of phytophagous insects to switch to new hosts underlies ecological and evolutionary processes such as range expansion, niche differentiation, and speciation. However, the genetic mechanisms underlying the ability to switch hosts are poorly understood. In this study, we used DNA microarrays to ask about changes in gene expression patterns in response to dietary shifts in Drosophila melanogaster, an ecological generalist. Larval diets included standard cornmeal culture medium as a control as well as several ecologically relevant fruits, vegetables, and necrotic cactus. Dietary shifts were associated with repeatable changes in gene expression. For example, larvae feeding on cactus exhibited transcriptional changes in 34 genes, 16 of known function, compared to those growing in control food. We discuss the implications of these functional genomic shifts for understanding an insect's ability to adapt to new food sources.

Key words: gene expression, generalist forager, dietary shift, Drosophila melanogaster