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.