Extensive genetic diversity of Anaplasma bovis in ruminants in Xi'an, China
Extensive genetic diversity of Anaplasma bovis in ruminants in Xi'an, China
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中国西安反刍动物中牛无形体的广泛遗传多样性
DOI：
10.1016/j.ttbdis.2020.101477
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发表时间：
2020-09-01
影响因子：
3.2
通讯作者：
Xie, Guang-Cheng
中科院分区：
文献类型：
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作者：
Guo, Wen-Ping;Tie, Wei-Fang;Xie, Guang-Cheng
牛无形体是牛和布法罗的重要病原体，是牛无形体病的病原体之一。以往的研究表明，A.牛然而，这些关于其遗传多样性的研究大多只集中在rrs基因上。本研究中，A.采用巢式PCR方法对西安市牛、羊血液中的牛疱疹病毒进行了检测。从阳性样品中成功扩增了近全长rrs、groEL和gltA基因。遗传学分析表明，在部分菌株的rrs序列中发现了特异性遗传标记（一个插入和一个缺失），以及先前研究中来自猴的克隆88。基于rrs、groEL和gltA基因的系统发育分析表明，A.西安地区牛具有丰富的遗传多样性。研究结果还表明，中国以外的变异体呈现地理聚集性，所有的A。基于groEL或gltA基因的牛分离物也显示出宿主来源聚类。groEL和gltA基因的系统发育分析表明，近年来的频繁远距离扩散和长时间进化的局部适应在A的分布和进化中起重要作用。牛在中国最后，基于groEL和gltA树中的不一致位置，还观察到周至牛-10的基因组中的潜在重组事件。这些结果也加强了评估A.在rrs基因中具有特异性标记的牛变体。
Anaplasma bovis is an organism significant to cattle and buffalo since it is one of the causative agents of bovine anaplasmosis. Previous studies have shown the worldwide distribution of A. bovis. However, most of these studies about its genetic diversity only focused on the rrs gene. In this study, DNA of A. bovis was detected in blood samples of cattle and goats in Xi'an city, China by nested-PCR. Near full-length rrs, groEL, and gltA genes were amplified successfully from the positive samples. Genetic analysis showed that specific genetic marker (an insertion and a deletion) was found in the rrs sequences in some strains, as well as clone 88 from monkeys in previous study. Phylogenetic analysis based on the rrs, groEL, and gltA genes revealed that A. bovis circulating in Xi'an exhibited great genetic diversity. Our results also indicated that variants outside China presented geo-graphic clustering, and all A. bovis isolates based on the groEL or gltA gene also showed a host origin clustering. Also of note was that the phylogenetic analyses of the groEL and gltA genes suggested that both frequent dis-persals over long distances in recent years and local adaptation over long evolutionary timescales played im-portant roles in the distribution and evolution of A. bovis in China. Finally, a potential recombination event in the genome of Zhouzhi-cattle-10 based on inconsistent positions in the groEL and gltA trees was also observed. These results also reinforce the need for assessing the pathogenicity to humans of A. bovis variants with specific marker in the rrs gene.