Molecular cloning and developmental expression of the vitellogenin gene in the endoparasitoid, Pteromalus puparum

A cDNA of the vitellogenin (Vg) protein gene was isolated from the endoparasitoid Pteromalus puparum and characterized. The putative coding sequence was found to be 5634 bp long, encoding 1803 amino acids in a single open reading frame. The chemically determined N-terminal amino acid sequence of vitellin completely matched the deduced amino acid sequence that follows a putative signal peptide of 17 amino acid residues. The Vg mRNA was detected in the fat body of late female pupae, whereas the ovary and male fat body lacked the Vg transcript. The Vg mRNA level in the fat body depended significantly on the developmental stage, reaching the highest level 0 h after eclosion. The haemolymph Vg titre appeared 24 h after the appearance of Vg transcript. A positive correlation between the titre and transcript level of Vg in individual female wasps was found.