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