Contribution of Distal-less to quantitative variation in butterfly eyespots

The colour patterns decorating butterfly wings provide ideal material to study the reciprocal interactions between evolution and development. They are visually compelling products of selection, often with a clear adaptive value, and are amenable to a detailed developmental characterization(1). Research on wing-pattern evolution and development has focused on the eyespots of the tropical butterfly Bicyclus anynana(2). There is quantitative variation for several features of eyespot morphology(3-5) but the actual genes contributing to such variation are unknown. On the other hand, studies of gene expression patterns in wing primordia have implicated different developmental pathways in eyespot formation(6-11). To link these two sets of information we need to identify which genes within the implicated pathways contribute to the quantitative variation accessible to natural selection. Here we begin to bridge this gap by demonstrating linkage between DNA polymorphisms in the candidate gene Distal-less (Dll) and eyespot size in B. anynana.