摘要: |
为了对新疆部分地区环形泰勒虫Tams1基因型及遗传多样性进行分析,本研究对新疆托克逊、艾丁湖、青河和伊吾地区奶牛血液DNA进行检测,采用PCR方法对Tams1基因扩增、克隆和测序,并进行序列比对。通过MEGA、DNAsp、NetNGlyc等软件及在线软件分析Tams1基因及其蛋白序列。结果显示:1)新疆地区23条环形泰勒虫序列除伊吾地区2号样品序列被归为G3型,其余均属于G1型;此外,新疆地区Tams1基因序列在核苷酸与氨基酸水平上分别具有90.1%~100%和83.9%~100%的相似性。2)Tams1序列在核苷酸的168~217和479~528位置之间可检测到广泛序列变异。通过Hd=0.994±0.006、π=0.071±0.002、S=178、h=38及k=52.32均显示Tams1序列较高的遗传多样性;中性指数结果显示当地环形泰勒虫Tams1基因单倍型数大于多态位点个数,遗传多样性呈平衡选择。3)Tams1蛋白的N末端显示出较大的序列变异性,在3个区域(氨基酸位置27~52、138~175和180~196)存在广泛变异。经B细胞抗原表位预测及3D结构同源建模,发现Tams1蛋白抗原位点多位于表面,其抗原性较好。综上,本研究发现本次备选采样点的环形泰勒虫具有较高的遗传多样性,该数据可为后续环形泰勒虫基因型和种群结构变化、不同致病特性及逃避宿主免疫机制等研究提供参考。 |
关键词: 环形泰勒虫 Tams1 基因分型 遗传多样性 |
DOI:10.11841/j.issn.1007-4333.2023.07.12 |
投稿时间:2022-08-13 |
基金项目:新疆自治区高校科研计划自然科学项目(XJEDU20201008);新疆自治区区域协同创新专项-上海合作组织科技伙伴计划及国际科技合作计划项目(2021E01001) |
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Genotype and genetic diversity analysis of Theileria annulata in selected areas of Xinjiang based on Tams1 gene |
GE Xiaomin,WEN Licui,MIAO Ronghao,LI Caishan,LIU Kaiqiang,CHEN Songqin,ZHENG Huizhen,BAYIN Chahan,GUO Qingyong*
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(College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi 830052, China) |
Abstract: |
To analyze the genotypes and genetic diversity of Tams1 of Theileria annulata in some areas of Xinjiang, in this paper, blood DNA of dairy cows in Toksun, Aiding Lake, Qinghe and Yiwu regions of Xinjiang was detected, cloning and sequencing of the Tams1 gene by PCR and sequences alignment were carried out. The Tams1 gene and its protein sequences were analyzed by MEGA, DNAsp, NetNGlyc and other online software. The results showed that: 1)All of the 23 sequences of T. annulata in Xinjiang were of genotypes 1 except for the sequence of sample 2 in the Yiwu region, which was classified as genotypes 3; In addition, Tams1 gene sequences in Xinjiang showed 90. 1%-100% and 83. 9%-100% similarity at the nucleotide and amino acid levels, respectively. 2)Extensive sequences variation was detected in the Tams1 sequences between nucleotide positions 168-217 and 479-528. The high genetic diversity of Tams1 sequence was shown by Hd=0. 994±0. 006, π=0. 071±0. 002, S=178, h=38 and k=52. 32; The neutrality index results showed that the number of haplotypes in the local T. annulata Tams1 gene was greater than the number of polymorphic sites, genetic diversity showed balanced selection. 3)The N-terminus of the Tams1 protein showed large sequences variability, with extensive variation exists in 3 regions(amino acid positions 27-52, 138-175, and 180-196). Through B cell antigen epitopes prediction and the 3D structural homology modeling, it was found that the Tams1 protein antigenic sites were mostly located on the surface, and its antigenicity was better. In conclusion, the study found that T. annulata at this alternative sampling sites has high genetic diversity, and this data can provide a reference for the follow-up studies on the genotype and population structure changes, different pathogenic characteristics and evasion mechanisms of host immunity. |
Key words: Theileria annulata Tams1 genotype genetic diversity |