Vitellogenin of the solitary bees Centris tarsata and Centris analis (Hymenoptera: Apidae): cDNA structural analysis and gene expression

Abstract

Vitellogenin (Vg) plays a vital role in the reproduction of oviparous species, as the precursor of the major egg storage protein. In bees, most of the studies of this protein rely on honey bees (Apis mellifera ), and very little is known in solitary species. The solitary bees Centris tarsata and C. analis were chosen to characterize vg cDNA and better understand its expression. The Vg-deduced amino acid sequences from these bees have typical Vg features found in other hymenopterans. Besides its main site of synthesis, the fat body, transcripts of vg were also observed in ovaries. Males also showed expression of vg , although in lower levels compared with females. During development, vg expression was observed in late larvae, pupae, and female adults. The highest amounts of vg transcripts were observed in egg-laying females. Expression of vg increased rapidly in a few hours after female adult emergence, which indicates that its gene expression does not depend on mating to be triggered. vitellogenin / gene expression / males / ovaries

Sex Reversal Induced by Dietary Supplementation with 17α-Methyltestosterone during the Critical Period of Sex Differentiation in Oriental River Prawn (Macrobrachium nipponense)

“…In oriental river prawns, the expression of androgen-related genes is decreased in the androgenic gland (AG) by RNAi-induced knockdown of IAG [ 22 ]. The rapid production and deposition of the yolk protein precursor vitellogenin (VG), which is used by embryos and larvae during early development, determine oocyte growth and gonadal maturation [ 23 , 24 ]. During vitellogenesis, the VG receptor (VGR) secretes VG into the hemolymph receptor-mediated endocytosis and incorporates VG into the developing oocyte, where it is eventually converted into yolk protein [ 25 ].…”