亚洲玉米螟神经肽羽化激素基因cDNA的克隆及组织表达

羽化激素对调节昆虫的蜕皮和发育起关键作用。亚洲玉米螟Ostrinia furnacalis是亚洲农业重要害虫之一，本实验研究了亚洲玉米螟羽化激素基因cDNA的分子结构和表达模式。利用兼并性引物RT-PCR技术，克隆了亚洲玉米螟羽化激素基因cDNA的中间片段，然后再用RACE方法，获得羽化激素基因的 cDNA全长序列。结果表明： 亚洲玉米螟羽化激素基因cDNA全长986 bp（GenBank登录号： DQ668369），开放阅读框为267 bp，编码88个氨基酸的前体蛋白，其中包括前26个氨基酸组成的信号肽和62个氨基酸的成熟肽。亚洲玉米螟羽化激素基因与烟草天蛾、棉铃虫和家蚕已报道同源基因的同源性较高，分别为79.5%、77.3%和67.0%，与黑腹果蝇同源基因的同源性最低，仅45.5%。亚洲玉米螟羽化激素基因mRNA只在脑中表达，在咽下神经节、胸神经节、腹神经节等神经组织中检测不到，在非神经组织如中肠、脂肪体和表皮中也不表达。

Molecular cloning and tissue expression of the cDNA of the gene encoding eclosion hormone in the Asian corn borer,Ostrinia furnacalis (Lepidoptera:Pyralidae)

Eclosion hormone(EH),one of the neuropeptides,serves as a critical factor in the control of ecdysis behavior and development in insects.The Asian corn borer,Ostrinia furnacalis(Osf)is one of the major agricultural pests in Asia.In this study,the molecular characterizations and tissue expression of the eclosion hormone gene in O.furnacalis were elucidated.Using degenerate primers and RT-PCR method,the middle part of the cDNA of EH gene from O.furnacalis was cloned and sequenced.The full-length cDNA of EH gene was then obtained with rapid amplification of cDNA ends(RACE)method.The full Osf-EH cDNA is 986 bp(GenBank accession no.DQ668369),containing a 267 bp open reading frame encoding an 88-amino acid preprohormone.After translation,the preprohormone was cleavaged to a hydrophobic 26-amino acids signal peptide and a 62-amino acids mature peptide.The Osf-EH shows high identity with those from Manduca sexta(79.5%),Helicoverpa armigera(77.3%)and Bombyx mori(67.0%),but low identity with that of Drosophila melanogaster(45.5%).RT-PCR analysis showed that the EH mRNA only expressed in the brain,and was not be detected in other neural tissues,such as suboesophageal ganglion,thoracic ganglion,abdominal ganglion,and non-neural tissues,such as midgut,fat body and epidermis.