Melanophores of the isolated tail fin of the Xenopus tadpole respond to light, resulting in melanin aggregation in the melanophores.

Western blot analysis showed that a protein in the Xenopus tail fins, in which photosensitive melanophores exist, had reacted with the antibody against bovine rhodopsin.

RT-PCR and nested-PCR using rhodopsin-specific primers showed the expression of rhodopsin mRNA in the tail fins. The amino acid sequences deduced from the PCR products were completely identical to those of rhodopsin.

We also detected the mRNA of melanopsin in the tail fin, another opsin originally described in cultured melanophores of Xenopus.

These results indicate that these two types of opsin molecules exist in Xenopus tail fin and may take part in the photo-response in melanophores of the Xenopus tadpole.