
Fig. 1. Phylogenetic tree of opsin gene sequences. The tree was generated by the neighbour-joining method (Saitou and Nei, 1987). The bootstrap confidence values are shown for each branch. The scale bar is calibrated at 0.02 substitutions per site. GenBank accession numbers: Fugu rod-line brain AF201472, Goldfish rod L11863, blue cone L11864, green cone l11865 and red cone L11867; chicken rod D00702, violet cone M92039, blue cone M92057, green cone M92038 and red cone X57490, and Drosophila Rh3 M17718.