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为研究亚洲玉米螟Ostrinia furnacalis(Guen e)幼虫体内储存蛋白(SP)表达调控的分子机制,根据不同昆虫储存蛋白基因序列的保守区域,设计合成简并引物,采用RT-PCR技术从亚洲玉米螟5龄幼虫中扩增出一段cDNA片段,大小为892bp,编码297个氨基酸,预测分子量为35.7kD,理论等电点pI值为8.73。该基因序列中含有保守的幼虫储存蛋白(LSP)两个特征基序YFTEDIDLNTYYYYFHVDYP和TALRDPVFC。Blast P分析结果表明:该片段推导的氨基酸序列与斜纹夜蛾Spodoptera litura适量甲硫氨酸SP-1的一致性最高,为77%;与小菜蛾Plutella xylostella富含甲硫氨酸SP-1和SP-2、印度谷螟Plodia interpunctellaSP、美国白蛾Hyphantria cuneaSP-2和粉茎螟Sesamia nonagrioides适量甲硫氨酸SP氨基酸序列的一致性分别为74%、74%、72%、71%和65%。构建系统发育树分析了9种鳞翅目昆虫储存蛋白进化关系,结果显示:亚洲玉米螟cDNA片段氨基酸序列与小菜蛾富含甲硫氨酸SP-1的亲缘关系最近,与粉茎螟适量甲硫氨酸SP亲缘关系最远。
In order to study the molecular mechanism of in vivo storage protein (SP) expression in larvae of Ostrinia furnacalis (Guen e), the degenerate primers were designed according to the conserved regions of different insect protein genes. RT- The fifth instar larvae amplified a cDNA fragment with a size of 892 bp and encoded 297 amino acids. The predicted molecular weight was 35.7 kD and the theoretical isoelectric point (pI) was 8.73. The gene sequence contains conserved larval storage protein (LSP) two characteristic motifs YFTEDIDLNTYYYYFHVDYP and TALRDPVFC. The results of Blast P analysis showed that the deduced amino acid sequence of this fragment had the highest identity with the appropriate amount of methionine SP-1 of Spodoptera litura (77%), and the highest homology with the methionine-rich SP-1 of Plutella xylostella The concordance of amino acid sequence of SP-2, Plodia interpunctellaSP, Hyphantria cunea SP-2 and Sesamia nonagrioides moderate methionine SP were 74%, 74%, 72%, 71% and 65% . Phylogenetic tree phylogenetic tree analysis of the evolutionary relationships of nine kinds of Lepidoptera insect storage proteins showed that the amino acid sequence of the cDNA fragments of Asian corn borer and diamondback moth rich in methionine SP-1 the closest relationship with the amount of powdery stem borer Threonine SP relationship is the farthest.