Figure 2. Positively selected genes involved in the phototransduction pathway in rods (according to KEGG pathway: map04744).

For convenience, the genes involved in the phototransduction pathway in cones are also shown. Dark rectangles, white rectangles and grey rectangles show genes involved in the phototransduction pathway of rods, cones and both, respectively⁷. All the known principle genes involved in the phototransduction pathway are shown. The genes under investigation in this study are shown in italics. Positively selected genes found in Strigiformes, Falconiformes, Accipitriformes and Coraciimorphae are shown in red, green, violet and blue, respectively. *Shows two genes GNGT1 and PDE6A, which have no transcripts found in our 15 species. The absence of PDE6A in birds found here is consistent with previous studies⁵⁶,⁵⁷,⁵⁸. See text for the meanings of protein abbreviations and the functions of their corresponding genes. Solid line shows direct interaction and dashed line shows indirect interaction.