Abstract: It was to study Vitellogenin（Vg）and the function of Vg gene in G. pallidipennis. In this study, the gene cloning, sequence analysis and expression studies of Vg gene of G. pallidipennis were carried out by RT-PCR, RACE and ELISA. The full-length cDNA of the Vg gene was 5 667 bp（GenBank accession number：KP688587）, encoding 1848 amino acids residues, and there was a signal peptide of 19 amino acids in N-terminal. There were 2 conserved polyserine regions and 1 RXXR cleavage site in amino acid sequences. Close to the C-terminus there was a GLAG motif followed by 5 conserved cysteine residues, and a DGYR motif was located in the 18th residue of the GLAG upstream. The deduced amino acid sequence of the Vg gene showed a high similarity with the Vg sequences from other hemipterainsects. Typical features of Vg were found through sequence analysis. The results indicated that the cDNA obtained was Vg gene from G. pallidipennis. The Vg detected by ELISA showed it increased gradually and reached the peak on the 22th day after adult emergence, then decreased. The results also indicated that the egg production was closely correlated to Vg expression.

Key words: Geocoris pallidipennis, vitellogenin, gene cloning of Vg, sequence analysis, expression of Vg