Genes and the Environment: Gene Expression Profiling in Manduca sexta

The tobacco hornworm Manduca sexta is a model organism in the field of ecology; in nature Manduca rapidly adapts to changes in the environment, which enact changes in the animals physiological state. One possible mechanism of adaptation is gene regulation. We aim to analyze the impact of a variety of factors on the expression of single genes as well as complete gene networks by using RNAseq, focusing on factors of ecological relevance. So far we have generated data regarding changes in adult mating status, activity and rest phases, and larval diet; circardian rhythm is scheduled. For analysis we initially focus on larval diet. Here, Manduca larvae were placed on different host plants (Nicotiana attenuata, Datura wrightii, Lycopersicon esculentum), a non host plant (Brassica napus) as well as the standard artificial diet. RNA was isolated from salivary glands, gut, sensory organs (antennae and maxillae) and corresponding cDNA was sequenced using Illumina technology. Using preliminary data from the Manduca genome project we could identify differentially expressed genes. Characterization of identified genes of interest by in situ hybridization and qPCR for analysis of spatial and temporal expression is ongoing. Long term goal of our studies is to elucidate regulatory networks involved in adaptation to the environment.