We are studying the expression of genes during the formation of wing patterns. The pigment pathways involved in producing Heliconius colours are well characterised in Drosophila, so we can identify homologues in Heliconius and study their expression. Laura Ferguson has identified several genes that have expression patterns correlated with pigment distribution. These genes are the downstream targets of the loci that control presence or absence of wing pattern elements – the ‘switch loci’ that can be studied in crossing experiments.
In addition we have identified candidate loci for the switches between major phenotypic pattern elements, and are starting to look at their expression in developing wings.