Fig. 3. Identification of RH2 opsin. (A) Amino acid sequence of S. analis RH2 opsin aligned with the orthologous sequence from Metriaclima zebra. Note the additional Ser residues near the C terminus of the S. analis sequence. (B) Phylogenetic tree of RH2 opsin nucleotide sequences generated by the neighbour-joining method. The RH1 sequence from Carassius auratus was used as an outgroup. All sequences were aligned with ClustalV. Accession numbers for the sequences (in order from the top of the tree) are as follows: DQ088651, DQ088650, AY296739, Y18680, AY631037, AY771352, NM_001033712, AF38524, EF517406, AY599603, DQ088652, AB223053, AY214132, AF425076, AB098703, AB098704, AB087805, AB087806, AB087807, AB087808, L11865, AB110603, L11866, AB110602, L11863.