Microsatellite analysis of Toxoplasma gondii shows considerable polymorphism structured into two main clonal groups
Microsatellite analysis of Toxoplasma gondii shows considerable polymorphism structured into two main clonal groups
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DOI：
10.1016/s0020-7519(01)00301-0
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发表时间：
2002-01-01
影响因子：
4
通讯作者：
Dardé, ML
中科院分区：
文献类型：
--
作者：
Ajzenberg, D;Bañuls, AL;Dardé, ML
以往对弓形虫种群结构的研究，主要是基于多位点限制性片段长度多态性分析或多位点酶电泳，表明弓形虫种群结构是一个复杂的系统。弓形虫包括三个克隆谱系。这些研究表明标记的多态性较弱（每个基因座有2-4个等位基因）。在这项研究中，我们使用8个微卫星标记对来自人类和动物的84个独立分离株进行分型，两个微卫星标记存在于两个基因的内含子中，一个编码β-微管蛋白，另一个编码肌球蛋白A，并且在表达序列标签中发现了6个。这些标记可检测到3-16个等位基因，可被认为是可用于T分型的最具鉴别力的多位点单拷贝标记。弓形虫分离株微卫星的这种高区分能力使得有可能检测混合感染和流行病学相关的分离株。多样性的进化遗传分析表明，T。弓形虫种群结构仅由两个克隆谱系组成，这两个谱系可等同于离散的分型单位，但有一些证据表明，偶尔的遗传交换可以解释为什么这些离散的分型单位之一比另一个个体化程度低。(C)2002年澳大利亚寄生虫学会由爱思唯尔科技有限公司出版。保留所有权利。
Previous studies on Toxoplasma gondii population structure, based essentially on multilocus restriction fragment length polymorphism analysis or on multilocus enzyme electrophoresis, indicated that T. gondii comprises three clonal lineages. These studies showed a weak polymorphism of the markers (2-4 alleles by locus). In this study, we used eight microsatellite markers to type 84 independent isolates from humans and animals, Two microsatellite markers were present in the introns of two genes, one coding for beta-tubulin and the other for myosin A, and six were found in expressed sequence tags. With 3-16 alleles detected, these markers can be considered as the most discriminating multilocus single-copy markers available for typing T. gondii isolates. This high discriminatory power of microsatellites made it possible to detect mixed infections and epidemiologically related isolates. Evolutionary genetic analyses of diversity show that the T. gondii population structure consists of only two clonal lineages that can be equated to discrete typing units, but there is some evidence of occasional genetic exchange that could explain why one of these discrete typing units is less clearly individualised than the other. (C) 2002 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.