Roles of Vitellogenin and Its Receptor Genes in Female Reproduction of the Cigarette Beetle, Lasioderma serricorne

Vitellogenin (Vg) and the vitellogenin receptor (VgR) play essential roles in insect reproductive development. However, the functions of Vg and VgR genes in Lasioderma serricorne, an important insect pest of stored products, are unknown. We identified and characterized these two genes, designated LsVg and LsVgR, in L. serricorne. The open reading frames of LsVg and LsVgR were 5232 and 5529 bp, encoding 1743 and 1842 amino acid residues, respectively. Both LsVg and LsVgR were predominantly expressed in female adults and exhibited the highest expression in ovaries. The RNAi-mediated silencing of LsVg or LsVgR significantly decreased the average length of ovarian tubes and oocytes and severely affected ovarian development. The Knockdown of LsVg or LsVgR significantly reduced the oviposition period, the number of eggs laid, and the egg hatching rate. Females injected with dsLsVg and dsLsVg + VgR were found to had decreased vitellogenin content. The co-silencing of LsVg and LsVgR had a more pronounced effect on reducing the oviposition period and female fecundity in L. serricorne. This study revealed the importance of LsVg and LsVgR in regulating female reproduction and shows their potential as targets for RNAi-based control of L. serricorne.