Organization, evolution and expression of a multigene family encoding putative members of the odourant binding protein family in the medfly Ceratitiscapitata

A multigene family encoding male specific serum polypeptides (MSSPs) that s how significant structural similarity to the family of insect odourant bind ing proteins, has been characterized in the medfly Ceratitis capitata. This family comprises seven members classified in three subgroups, MSSP-alpha, MSSP-beta and MSSP-gamma. The genes of subgroups alpha and beta are cluster ed in tandem in a 35-kb genomic region, and present an exceptionally high d egree of similarity not only in their coding but also in the surrounding re gions, while the genes of the gamma subgroup are drastically divergent. Alt hough MSSPs are predominantly expressed in the male fat body, detailed expr ession studies suggest that individual members of this family are expressed in a distinct sex- and tissue-specific manner.