Differential gene expresion in Drosophila koepferae reared in alternative host plants

CORIO, C.; RUSSO, M. G.; BETTI, M.; SOTO, E. M.; FANARA, J. J.; HASSON, E.

Kansas City, Estados Unidos

Simposio; 7th Annual Ecological Genomics Symposium; 2009

Saprophytophagous insects are excellent models to study the genetic and ecological basis of adaptation to new host plants and divergence since the host plant are the most immediate environmental factor that affect early stages of their life cycle. Host plant shifts may represent a new challenge since it may entail new feeding sources, to face a new chemical environment (including the presence of potentially toxic compounds), a different microflora (bacteria, yeasts and fungi) and new mating environments. Cactophilic species of the Drosophila repleta group has long constituted a model system, that involves flies, yeasts and cacti, to study the importance of host plant shifts in species divergence and diversification.In South America the D. buzzatii cluster is a group of seven species in active cladogenesis. Drosophila koepferae is one of the members of this cluster that inhabits vey arid areas in North Western Argentina and Souther Bolivia. In some areas of its present distribution D. koepferaeuses the necrotic tissues of the columnar cactus  Trichocereus terschekii (Fig. 1B) as the main host plant and the rotting cladodes of the prickly pear Opuntia sulphurea (Fig. 1A) as secondary host. The objective of the presen work is to understand the mechanisms involved in the differential use of these two types of resources. We aim to identify the genes that are differentially expressed in larvae grown in natural media prepared with rotting materials of the primary and the secondary host plants.