Characterization and tissue distribution of multiple agouti-family genes in pufferfish, Takifugu rubripes.

Four types of agouti-family genes (AGRP1, AGRP2, ASIP1 and ASIP2) were obtained from torafugu, Takifugu rubripes. Their characterization and structure were analyzed to elucidate the relationship among the torafugu agouti-family genes. Both AGRP1 and AGRP2 showed genomic synteny with the human AGRP gene. Phylogenetic tree analysis showed that AGRP1 formed a cluster with human AGRP. We inferred that torafugu AGRP1 and AGRP2 are orthologs of human AGRP and that they are paralogous genes derived from genome duplication occurred in the teleost phylogeny. Torafugu ASIP1 showed genomic synteny with the human ASIP, but ASIP2 did not. The ASIP1 expression level was about five times higher in the white ventral skin than in the black dorsal skin. Therefore, we concluded that torafugu ASIP1 is an ortholog of human ASIP, nevertheless, we are unable to determine if torafugu ASIP2 is a paralog of ASIP1 or not.