Meeting Abstract

P3.183  Tuesday, Jan. 6  The diversity of visual perception in sympatric Lake Victoria cichlids MIYAGI, R*; TERAI, Y; AIBARA, M; MIZOIRI, S; SUGAWARA, T; IMAI, H; WACHI, N; TACHIDA, H; OKADA, N; Tokyo Institute of Technology, Yokohama; Tokyo Institute of Technology, Yokohama; Tokyo Institute of Technology, Yokohama; Tokyo Institute of Technology, Yokohama; Kyoto University, Inuyama; Kyoto University, Inuyama; Kyusyu University, Fukuoka; Kyusyu University, Fukuoka; Tokyo Institute of Technology, Yokohama miyagi.r.aa@m.titech.ac.jp

Lake Victoria harbors hundreds of endemic species of cichlids which have experienced explosively adaptive radiation during a very short period. They are ecologically and morphologically highly diverse whereas genetic differentiations among species are extremely low. Lake Victoria cichlids are one of the well-studied organisms at the genetic mechanisms of sensory drive speciation. In allopatric and parapatric distribution cases, the adaptation of visual systems and the evolution of nuptial color might cause reproductive isolation that lead to speciation. We studied the diversity of visual system in sympatric cichlids that has not been reported. We determined the sequences of opsin genes, which code photoreceptor proteins, from seven sympatric species. The LWS and RH1 genes showed the species-specific amino acid replacements, and showed higher degree of diversification between each species than those in neutral regions. Especially in two species, the divergent natural selection has acted on LWS gene regions detected by population genetic analysis using LWS and its flanking regions. The LWS pigments reconstituted from LWS of those two species absorbed different spectra suggesting functional diversification. These results suggest that even in sympatric cichlids had species-specific visual perception. The visual systems of sympatric cichlid species might have adapted not only to light environments but also to species-specific microhabitats including ecological features such as feeding and mating behaviors.