SISON-MANGUS, MP*; BRISCOE, AD; University of California, Irvine; University of California, Irvine: Evolutionary origin of a blue opsin gene duplication in lycaenid butterflies

Duplication of opsin genes followed by functional diversification is the evolutionary mechanism that enabled invertebrates to gain trichromatic vision. Recently, a novel blue opsin duplication was found in the genus Lycaena that was not found in other closely related butterfly families. The spatial expression patterns of the two blue opsin genes in the Lycaena retina were also distinct from each other. In order to elucidate the relative timing of the duplication event, and whether it is widespread amongst lycaenids, we screened for the presence of blue opsin genes from cDNA libraries of butterflies belonging to other lycaenid subfamilies, Theclinae (Satyrium behrii) and Polyommatinae (Polyommatus icarus). These data will be discussed in relation to site-specific and lineage-specific models of adaptive evolution and in relation to both spectral tuning and homology models of the closely-related proteins.