The smell of speciation: chemical signalling in butterfly diversification

The integration of genomic data with ecological and behavioural observations of the Heliconius butterflies provides an
excellent opportunity to study the genomic consequences of speciation. Interspecific wing pattern variation in this group
has been particularly well studied but we know much less about their chemical communication, which also plays an
important role in sexual communication and species recognition. A key compound in sexual signalling has recently been
identified in H. melpomene along with electrophysiological evidence for its role in mate choice. In addition, foundations
have been laid for investigating the genetic basis of pheromonal differences between H. melpomene and H. cydno by
recent crossing experiments and genomic (QTL) analysis. This project will study such pheromonal differences in males
and the corresponding female preferences. The work will involve experiments to follow up on the genomic analysis
currently underway, including genetic manipulation experiments using CRISPR to test the function of candidate wing
pheromone genes. This will be complemented by behavioural assays with resulting male mutants to study the role of
specific genes in mating behaviour. In addition, I will raise additional controlled crosses and conduct chemical analysis of
hybrid butterfly wing samples to identify important compounds. I will then conduct further behavioural assays using
synthesised compounds to study the role of specific compounds in female preference.