中文摘要：

为获得甜菜夜蛾Spodoptera exigua（Hübner）P450基因序列并分析其分布的组织特异性,采用同源克隆结合RACE技术克隆得到了该基因的cDNA全序列：全长2 565bp,包含1 010bp的3′非编码区域和42bp的5’非编码区域,开放阅读框（ORF）长1 515bp,编码504个氨基酸,分子量为57.74kD,理论等电点为8.01;包含2个糖基化位点,2～21aa为跨膜结构.同源比对结果表明,SeP450与其它昆虫的P450基因拥有同样的2个保守结构域：CAFG、AG／ET.SeP450与棉铃虫蛾Helicoverpa armigera P450同源性最高,达74%;系统发育分析也表明二者亲缘关系较近.同时RT-PCR结果显示SeP450mRNA在中肠、脂肪体等多种组织中都有表达,其中中肠表达量最高.

英文摘要：

In order to obtain P450 gene sequence in Spodoptera el＇igua and analyze the tissue distribution, homology coloning and RACE were adopted to colone the eDNA of Spodoptera exigua P450. The full length of cDNA with calculated molecular mass of 57.74 kD and pI of 8.01 is 2 565 bp, which includes an ORF of 1 515 nucleotides that encodes 504 amino acid residues and a 42 or 1 010 nucleotide for 5% or 3t non coding region respectively. It has two glycosylation sites, the 2 - 21 aa is transmembrane structure. Homologous comparison results indicate that SeP450 contains two conservative domains the same as the P450 gene in other insects, including CAFG and AG／ET. SeP450 shares 74 % identity with that of Helicoverpa armigera, which is the highest and the phylogenetic analysis shows that the two species are most closely related. The result of RT-PCR show that SeP450 mRNA is expressed in midgut, fat body and other tissues, with the highest expression level in the midgut.