A NOVEL AND ANCIENT VERTEBRATE OPSIN

We describe the identification of a novel opsin gene isolated from the eyes of Atlantic salmon, The cDNA sequence predicts a protein that ha s the key features of an opsin, but shows only 32-42% amino acid ident ity to the known opsin families, Phylogenetic analysis suggests that t his opsin is a member of a hitherto unrecognised opsin family that div erged early in the evolution of vertebrate photopigments. We have tent atively called this opsin family the vertebrate ancient (VA) opsins, T he identification of VA opsin may ultimately help to resolve some of t he uncharacterised photoreceptor functions of the eye, which include t he regulation of circadian rhythms, pupil size and corneal pigmentatio n. (C) 1997 Federation of European Biochemical Societies.