Fig. 3. Phylogenies of the UV, B and LW opsin genes of each of the five butterfly families including genes corresponding to the visual pigments shown in Fig. 2. The neighbor-joining method using 1st+2nd nucleotide positions and the Tamura-Nei model of evolution was used. Numbers represent the percentage of trees in which a particular node was recovered out of 500 replicates. The moths Manduca sexta (Sphingidae) and Bombyx mori (Bombycidae) are used as outgroups. (A) UV opsin gene tree. Opsin genes encoding the UV-absorbing visual pigments in Fig. 2 are indicated by bold gray. In each of the butterfly species shown, the UV visual pigment is encoded by a single-copy gene. The full-length UV opsin cDNA of A. mormo is newly presented in this study (GenBank accession no. AY587905). (B) B opsin gene tree. Opsin genes encoding the B-absorbing visual pigments in Fig. 2 are shown in bold purple. Duplications of the B opsin gene have been observed twice in independent butterfly lineages: once in the pierid P. rapae giving rise to the violet receptor (PrV) (light purple) (Arikawa et al., 2005), and once in the lycaenid L. rubidus, giving rise to a blue–green (B2)-sensitive photopigment (BRh2; blue) (Sison-Mangus et al., 2006). (C) LW opsin gene tree. Opsin genes encoding the LW-absorbing visual pigments shown in Fig. 2 are indicated by bold orange, yellow and green. LW opsin gene duplications have occurred in three of five butterfly families independently. Besides those in Papilio, LW opsin duplicate genes have been recovered from the eye of the riodinid Apodemia mormo and from the genomic DNA of the nymphalid Hermeuptychia hermes (not shown) (Frentiu et al., 2007a). Scale bars indicate substitutions per site.