Initial characterization of the vitellogenin receptor from a Psocoptera insect: Function analysis and RNA interference in Liposcelis entomophila (Enderlein)

Abstract

The psocid Liposcelis entomophila (Enderlein) is a nuisance pest of stored products, owing to its high reproduction capability. While vitellogenin receptor (VgR) is an important carrier for the uptake of vitellogenin (Vg) into developing oocytes, the identification and function of VgR in psocids remain unexplored currently. This study identified and characterised the full-length cDNA of L. entomophila vitellogenin receptor (LeVgR). The results revealed that LeVgR is 5916 bp long; encodes 1811 amino acid residues, and belongs to the low-density lipoprotein receptor (LDLR) gene superfamily. LeVgR was expressed exclusively in the ovary, first transcribed in 4th-instar nymphs, and then the transcript level increased gradually from adult emergence, reached the highest level in 13-day-old female adults, and gradually declined in 15- to 23-day-old female adults with slight fluctuations. Feeding with dsLeVgR disturbed the normal expression pattern of LeVgR, leading to a decrease in egg count and hatchability and inhibited ovary maturation. These results suggest that VgR is critical for the uptake of Vg into oocytes and plays a vital role in female reproduction. Furthermore, VgR may be an important potential target to disrupt insect reproduction for pest management by oral delivery of dsRNA.