Molecular characterization of a blue visual pigment gene in the fish Astyanax fasciatus.

We report here the isolation and sequence determination of a gene closely linked to the Astyanax red visual pigment gene. Reverse transcription polymerase chain reaction assays show that this new gene (B23 Af) and the previously characterized red and green visual pigment genes of Astyanax are all expressed in the eye. Phylogenetic analysis shows that B23Af belongs to the group consisting of short wavelength-sensitive pigment genes from different species and is most closely related to the goldfish blue visual pigment gene.