Isolation and characterization of melanopsin photoreceptors of Atlantic salmon (Salmo salar).

Melanopsins constitute a recently described group of vertebrate opsin photoreceptors that are involved in nonvisual photoreception. Here we describe the identification of six melanopsin genes of Atlantic salmon (Salmo salar), a valuable teleost model for studying nonvisual photoreception and the basis of photoperiodism. The results show that genes belonging to two different groups, the mammalian-like (Opn4m) and the Xenopus-like (Opn4x) melanopsins have been duplicated in teleosts.