Evolution of the olfactory system in feeding versus non-feeding moths
Dr S Bisch-Knaden
Prof N VanDam
No more applications being accepted
Competition Funded PhD Project (Students Worldwide)
Background: Nocturnal animals like moths rely on their sense of smell when searching for food sources. Most hawk moths, for example, feed on floral nectar and are strongly attracted by the scent of night-blooming plants. We could recently show that nectar feeding is disrupted if we knock-out a specific set of olfactory receptors (odorant receptors, ORs) in the tobacco hawk moth, Manduca sexta , showing that ORs are crucial for foraging. Closely related moth species, however, have reduced mouthparts as an adult and are not able to feed. Hence, the olfactory system of these moths might by different from that of their long-tonged relatives.
Project Description: The aim of the project is to compare ORs from feeding and non-feeding moths belonging to the Bombycoidea, an ecologically diverse and species-rich superfamily of Lepidoptera. We hypothesize that the need to find floral nectar sources shaped the evolution of ORs by e.g. species-specific expansion of single receptor genes. Accordingly, the representation of odors in the insect’s brain might differ in feeding and non-feeding moth species. To clarify these questions, the olfactory genome and transcriptome of 14 commercially available bombycoid moth species (9 feeding, 5 non-feeding) will be established — as it has been done recently for M. sexta in our lab  — and compared. Using in vivo calcium imaging of the olfactory brain, potential similarities and differences in the neuronal coding of typical floral volatiles will be studied [3, 4]. This way, we hope to identify individual odorant receptors and olfactory pathways essential for the detection of food sources.
Candidate profile: The candidate should have a strong background in molecular biology and bioinformatics, and should be interested in learning electrophysiological methods.