关键词: 烟粉虱, 卵黄原蛋白受体, 基因克隆, 序列分析, 表达谱

Abstract: Vitellogenin receptor (VgR) is one of the key factors during the uptake of vitellogenin (Vg) by oocytes, and plays a critical role in vitellogenesis and oocyte development. In order to define the physiological function of VgR, VgR cDNA in the whitefly, Bemisia tabaci Middle East-Asia Minor 1 (MEAM1) was sequenced using the combined methods of reverse transcription PCR (RT-PCR) and rapid amplification of cDNA ends (RACE). The bioinformatical analysis demonstrated that the full-length cDNA of VgR from B. tabaci MEAM1 is 5 774 bp in size. The putative mature VgR has 1 919 amino acids with a molecular weight of 201 kDa. The signal peptide at the N-terminal end contains 31 amino acids. The VgR of this whitefly has all the typical conserved domains of the low density lipoprotein receptor (LDLR) family. The expression profile of VgR gene at different developmental stages of the whitefly was detected by realtime quantitative PCR. The results showed that the expression of VgR gene was initiated at the pseudo-pupal period and increased rapidly on the 1st day after eclosion and reached the peak level on the 7th day after eclosion. These results will enrich the gene database of VgR and provide valuable information to ascertain the regulation mechanism of vitellogenesis in B. tabaci.

Key words: Bemisia tabaci, vitellogenin receptor, gene cloning, sequence analysis, expression profile