牛无浆体16S rRNA基因的克隆测序及分析

Cloning and Sequence Analysis of the 16S rRNA Gene of Anaplasma bovis in Cattle

从自然感染无浆体的重庆黄牛无菌采集血液,提取全血基因组,用血营养菌16S rRNA基因的通用引物进行PCR扩增,得到长约1500bp的扩增片段,将其克隆到pMD18-T载体后进行测序,并与5条边缘无浆体、4条中央无浆体、4条牛无浆体、4条羊无浆体和3条嗜吞噬细胞无浆体16S rRNA基因序列进行系统发育分析。结果表明所克隆的基因片段长度为1412bp,GenBank登录号为FJ169957。序列比较结果显示,所获得的序列与Kawa-hara公布的牛无浆体日本株(AB211163)同源性最高,达到99.0%,系统发育分析发现,该序列被聚类到牛无浆体群,并与嗜吞噬细胞无浆体群聚类到一个大的分支。本文从分子水平证实重庆地区存在牛无浆体,牛无浆体与嗜吞噬细胞无浆体的亲缘关系比其他3种无浆体更近。

In the study,we cloned and sequenced the 16S rRNA gene of Anaplasma bovis isolated from Zhongxian in Chongqing.The 16S rRNA gene of A.bovis was 1 412 bp in length.The sequence was submitted to GenBank（accession number：FJ169957）.The 16S rRNA gene of A.bovis（FJ169957） had highest homology（99.0%） with that by Kawahara published（AB211163）.In addition,5 homologous sequences from A.marginale,4 from A.centrale,4 from A.bovis,4 from A.ovis and 3 from A.phagocytophilum available were downloaded from GenBank.Phylogenetic analyses on Anaplasma 16S rRNA sequences were performed.The results indicated that A.bovis has closer genetic relationship to A.phagocytophilum than that to A.marginale,A.centrale and A.ovis.