棉铃虫酚氧化酶原基因的克隆、序列分析和组织表达

利用RT-PCR和RACE方法，获得了棉铃虫Helicoverpa armigera酚氧化酶原(prophenoloxidase，PPO)基因一个亚型cDNA的完整序列。该序列全长2 405 bp，含有一个2 097 bp的开放阅读框，编码一个由698个氨基酸残基组成的蛋白质。推导的氨基酸序列与其他鳞翅目昆虫PPO2基因相应氨基酸序列有较高的同源性(76％～80％)，同时该序列具有铜离子结合位点等PPO基因所具有的典型特征。组织特异性表达分析表明，该基因在棉铃虫血细胞、体壁和中肠中均有表达。

cDNA cloning, sequence analysis and tissue expression of a prophenoloxidase gene in Helicoverpa armigera

The cDNA of Helicoverpa armigera prophenoloxidase (PPO) was cloned by means of RT-PCR and RACE. The cDNA was 2 405 bp in length and contained an open reading frame (ORF) of 2 097 bp which encoded 698 amino acid residues. The deduced amino acid sequence showed a high identity to the reported sequence of PPO2 from other insects and shared the typical structural features of PPO from other insects. The results of RT-PCR showed that PPO mRNA was expressed in integument,haemocyte and midgut of H. armigera.