犬瘟热疫苗弱毒融合蛋白穿膜区基因的序列分析

Sequence Analysis of the Membrane Anchor Region of Canine Distemper Virus Fusion Protein Gene

本研究根据Ｂａｒｒｅｔ．Ｔ报道的犬瘟热病毒（ＣＤＶ）Ｏｎｄｅｒｓｔｅｐｏｏｒｔ株融合蛋白（Ｆ）的基因序列，设计合成了一对可扩增出穿膜区基因的引物（Ｐ８和Ｐ１０），此对引物扩增的ｃＤＮＡ长度应为６２０ｂｐ。以我国现用的某犬瘟热疫苗弱毒感染Ｖｅｒｏ细胞的总ＲＮＡ进行反转录，此反转录产物作为ＰＣＲ的模板，经扩增后得到了约为６２０ｂｐ的ＰＣＲ产物。将此ＰＣＲ产物和ｐＧＥＭ－Ｔ载体质粒连接、转化、鉴定后，得到了含有Ｐ１和Ｐ２间片段的质粒。将此质粒进行序列分析，结果在两引物间的核酸长度为５７４ｂｐ。其相对于ＣＤＶＯｎｄｅｒｓｔｅｐｏｏｒｔ株、海豹瘟热病毒２型（ＰＤＶ２）和海豹瘟热病毒１型（ＰＤＶ－１），在核苷酸水平分别有１５、４２和１７１个的变异，同源性分别为９７．４％、９２．７％和７０．２％。在氨基酸水平分别有７、９和４３个的变异，同源性分别为９６．３％、９５．２％和７７．５％，由此氨基酸序列推测的氨基酸疏水性分布图，与其它毒株大致相同，但由此而预测的该毒株的二级结构与其它毒株则有显著的不同，毒株的这种变异进而可能影响到其蛋白质的结构与功能。本研究首次报道了国内现用ＣＤＶ疫苗弱毒融合蛋白穿膜区的基因序列，为进一步研究?

A pair of primers were applied to amplify the membrane anchor region of canine distemper virus(CDV) fusion (F) protein gene.The templates were produced from the reverse transcription reaction that RNA were isolated form CDV attenuated strain infected Vero cell culture.A 620bp fragment was amplified by polymerase chain reaction.The fragment was indicated specific by restriction enyme analysis.The fragment was cloned and sequenced.There were 574 base pairs in the fragment excluding the 2 primers.There were 15,42 and 171 nucleotides and 7,9 and 43 amino acids respectively difference in comparison with CDV Onderstepoort attenuated strain,phocine distemper virus type 2(PDV 2) and PDV 1.The hydropathy profiles of this CDV attenuated strain were very similar to other strains.The secondary structure of the sequence was different from other strains.