Although butterflies are often thought to be very visual organisms, they also rely heavily on chemical information from their environment. Chemical information can be crucial in important decisions such as choosing a potential mate, or when a female chooses where to lay her eggs. Recent work in Heliconius has characterized some of the compounds used during mating (Estrada, Schulz, Yildizhan, Gilbert, 2011; Estrada, Yildizhan, Schulz, Gilbert, 2010).
Led by Adriana Briscoe, genomic approaches have been used to identify and characterise the genes involved in chemical detection. Odorant-binding proteins (OBPs), chemosensory proteins (CSPs) and odorant receptors (ORs) are families of genes known to play an important role in chemosensation. These are large gene families whose diversity is hypothesized to reflect ecological niches occupied by different insects. To explore how ecological divergence between moths and butterflies might be reflected in these groups of proteins we have comprehensively surveyed OBPs, CSPs, and ORs in H. melpomene as well as B. mori and D. plexippus. The gene predictions published in the genome paper are available here.
Ongoing work is now underway to study another important family of proteins, the Gustatory Receptors.