Fig. 1.

Phylogeny of the opsin family. (A) Unrooted phylogeny of the neuralian opsins. (B) Rooted phylogeny of the neuralian opsins and of other GPCRs showing that the Placopsins are members of the opsin family (Ore, orexin; Lys, lysosphingolipid). (C) Opsin phylogeny rooted by using only the MLT receptors, and showing that cnidarians have orthologues of each bilaterian opsin subfamily: the C, R, and Go/RGR subfamilies. Support values (Bayesian PPs) are reported only for key nodes (SI Appendix shows all support values). The ancestral RBD of the LOCA and of the LOCNA are reported and are identified, respectively, by a black star and a black circle (SI Appendix, Fig. S7). The red position in the logos identifies position 296.