Chinen, A., Hamaoka, T., Yamada, Y. and Kawamura, S. (2003). Gene duplication and spectral diversification of cone visual pigments of zebrafish. Genetics, 163 (2):663-675.

We showed that zebrafish has two red (LWS-1 and LWS-2), four green (RH2-1, RH2-2, RH2-3 and RH2-4) and single blue (SWS2) and ultraviolet (SWS1) opsin genes in the genome. SWS2, LWS-1 and LWS-2 are located in tandem and RH2-1, RH2-2, RH2-3 and RH2-4 form another tandem gene cluster. We also showed that peak absorption spectra (lambda max) of these visual pigments differed markedly each other by reconstituting functional photopigments in vitro. This is the first work which revealed all the visual opsin gene repertoire in fish and provided a solid basis on which further studies on expression and developmental regulation of the opsin genes are possible.