Abstract: The ORF and the 5′UTR sequences of serpin were cloned from Bombyx mori using RT-PCR and rapid amplification of cDNA ends (RACE) strategies. We named this gene as serpin-6 of B. mori, which was deposited in GenBank with the accession no. EU159447. In order to study the mechanism of immunity of serpin-6 from B. mori, we performed the tissue expression and detected the immunity response. The results of semi-quantitative RT-PCR showed that the mRNA of this gene was highly expressed in head and gonads, and lowly expressed in the midgut, fat body, silk glands and haemolymph. When day-3 fifth instar larvae were injected with LPS, the RT-PCR results showed that this gene was highly induced and it was highly expressed in the fat body and haemolymph, and the highest expression was at 6 h after injection. It is inferred that this serpin gene may play an important role in immunity of B. mori.

Key words: Bombyx mori, serpin-6, gene cloning, semi-quantitative RT-PCR, tissue expression, immune reaction