<i><scp>O</scp>smia cornifrons</i> vitellogenin: c<scp>DNA</scp> cloning, structural analysis and developmental expression

Abstract

Abstract O smia cornifrons plays a major role in the pollination of orchards, but basic information on vitellogenin and oocyte development is limited. To better understand vitellogenin in hymenopteran insects, we cloned a c DNA encoding vitellogenin from the hornfaced bee O . cornifrons . O smia cornifrons vitellogenin c DNA contains 5477 bp with an open reading frame of 1783 amino acid residues, and has a predicted molecular mass of approximately 200.21 k D a and a p I of 6.55. O smia cornifrons vitellogenin possesses four consensus ( RXXR / S ) cleavage sites and has conserved DGXR and GL / ICG motifs in the C ‐terminus. The deduced amino acid sequence of the O . cornifrons vitellogenin c DNA showed a 66% identity with M egachile rotundata , 53% to A pis mellifera , 51% to B ombus ignitus and 42%–30% with other hymenopteran insect vitellogenins. Phylogenetic analysis showed that O . cornifrons vitellogenin clustered with vitellogenins from M egachilidae, A pidae, V espidae and F ormicidae species but not with those from P teromalidae, A phelinidae or I chneumonidae species. The expression profile of O . cornifrons vitellogenin m RNA during development revealed that O . cornifrons vitellogenin was first detected in the pupal stage and was continuously detected during the adult stage. Interestingly, O . cornifrons vitellogenin m RNA expression was low in mid‐diapause, then gradually increased beginning on day 3 of the newly emerged adult stage, and subsequently declined. These results suggest that the expression level of O . cornifrons vitellogenin m RNA is stage‐specific.