作　　者： ; ; ; ; ; ;

机构地区： 中山大学生命科学学院有害生物控制与资源利用国家重点实验室

出　　处： 《生物化学与生物物理进展》 2008年第8期940-946,共7页

摘　　要： XnBP83是从Xenorhabdus nematophila BP基因组粘粒文库中筛选出的一个对棉铃虫有较强口服杀虫活性的克隆.采用亚克隆结合primer-walkingDNA测序技术对粘粒XnBP83的插入片段进行序列测定.该插入片段全长38939bp,其中包括5个与杀虫活性相关的tc类基因xptA1、xptB1、xptC1、xptA2、xptD1.序列分析显示:a.插入片段中的xptD1不完整,与X.nematophila PMFI296 XptD1相应氨基酸序列有99%的相似性.b.BPxptA1读码框全长7569bp,编码2520个氨基酸,与PMF1296的XptA1氨基酸序列有98%的相似性,两者在第2200～2223氨基酸区域连续有23个氨基酸不同.c.BPxptB1读码框全长3051bp,编码1016个氨基酸,与PMF1296XptB1氨基酸序列有98%的相似性,在第620～650氨基酸之间有28个氨基酸差异.d.BPxptC1读码框全长4225bp,编码1408个氨基酸,与PMF1296的XptC1氨基酸序列有96%的相似性.在BP的第232氨基酸后插入了一个TAQRYLAK的氨基酸序列,在第627～646氨基酸区域内,有18个氨基酸不同.e.BPxptA2读码框全长7574bp,编码2524个氨基酸,与PMF1296的XptA2氨基酸序列有90%的相似性,在BP品系XptA2的第788～855氨基酸和第1630～1784氨基酸有两个明显变异区.将XnBP83培养物上清和沉淀饲喂棉铃虫、甜菜夜蛾、斜纹夜蛾和粉纹夜蛾,结果表明XnBP83对所测昆虫有广谱杀虫活性. XnBP83 is a clone which had oral toxicity to Helicoverpa. arrnegera screened from the cosmid library of Xenorhabdus. nematophilus BP. Comsmid XnBP83 was sequenced using a strategy of subcloning and primer-walking DNA sequencing. The inserted sequences of XnBP83 have 38 939 bp including 50RFs that are associated to the insecticidal activity： xptA1, xptB1, xptC1, xptA2 and xptD1. The results of sequence analysis showed that： 1） The xptD1 of XnBP83 is incomplete, and shares 99% predicted amino acid sequence identity to that of X. nematophilus PMFI296.2） The xptA 1 of XnBP83 has 7 569 bp nucleotides, encoding 2 520 amino acids which shares 98% identical amino acid residues with that of PMFI296. 3） The xptB1 has 3 051 bp nucleotides, encoding 1 016 amino acids. The XptB1 sequence shares 98% identical amino acid residues with XptB1 of PMFI296. There are 28 different amino acids from 620 to 650 amino acids. 4） The xptC1 ofX. nematophilus BP has 4 225 bp, encoding 1 408 amino acids. The XptC 1 sequence shares 96% identical amino acid residues with that ofX. nematophilus PMFI296. There are 18 different amino acids from 627 to 646 amino acids. The amino acid sequence with TAQRYLAK was inserted to downstream to 232nd amino acid. And 5） The xptA2 has a length of 7 574 bp, encoding 2 524 amino acids. The XptA2 sequence shares 90% identical amino acid residues with that of PMFI296. Two distinctly divergence amino acid regions present from 788 to 855 and from 1 630 to 1 784 amino acids. Oral bioassay of the supernatant and cell sediment of XnBP83 against H. armegera, S. exiguo, S. litura, and T. ni showed that XnBP83 had broad-spectrum insecticidal activity.

关 键 词： 序列分析 粘粒 杀虫毒素基因 杀虫活性

领　　域： [生物学] [生物学]