Characterisation of large and small subunit rRNA and mini-exon genes further supports the distinction of six Trypanosoma cruzi lineages
Characterisation of large and small subunit rRNA and mini-exon genes further supports the distinction of six Trypanosoma cruzi lineages
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DOI：
10.1016/s0020-7519(01)00238-7
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发表时间：
2001-09-01
影响因子：
4
通讯作者：
Tibayrenc, M
中科院分区：
文献类型：
--
作者：
Brisse, S;Verhoef, J;Tibayrenc, M
有人提出，美洲锥虫病的病原体克氏锥虫分离株可分为两个主要系统发育谱系，首先基于多位点酶电泳和随机扩增多态性 DNA，随后基于 24S α rRNA 和迷你外显子基因。最近的多位点酶电泳和随机扩增多态性 DNA 数据还表明，主要的多位点酶电泳/随机扩增多态性 DNA 谱系 II 进一步细分为 5 个较小的谱系，指定为 IIa-IIe。在这项研究中。研究了多位点酶电泳/随机扩增多态性 DNA 和 rRNA/微型外显子谱系之间的精确对应关系。组合使用 24S α rRNA 和迷你外显子标记。区分了五组菌株，分别对应于多位点酶电泳/随机扩增多态性DNA谱系I、IIa、IIc、IId和一起谱系IIb/IIe。先前基于 24S α rRNA 和迷你外显子特征仅将其分为两个主要谱系，部分原因是早期研究样本中 T. cruzi 多样性的广度缺乏代表性。此外，基于 18S rRNA 基因长度可变区的 PCR 测定区分了谱系 Ile 和谱系 IIb。因此，通过组合来自 24S α rRNA 的数据，可以很容易地鉴定六种多位点酶电泳/随机扩增的多态性 DNA 谱系。迷你外显子和 18S rRNA 表征分析，进一步支持这些遗传单位与 T. cruzi 菌株分类和亚种命名的相关性。最近提出的群体 T. cruzi I 和 T. cruzi II 分别对应于多位点酶电泳/随机扩增多态性 DNA 谱系 I 和 IIb。我们的研究结果表明，基于单一标记（迷你外显子或24S α rRNA）的克氏锥虫谱系表征分辨率不足，并导致对基于过度简化的克氏锥虫分离株的rRNA/迷你外显子二分分类的近期流行病学和进化研究进行重要的重新解释。 (C) 2001 年澳大利亚寄生虫学协会。由 Elsevier Science Ltd 出版。保留所有权利。
It has been proposed that isolates of Trypanosoma cruzi, the agent of American trypanosomiasis, can be ordered into two primary phylogenetic lineages, first based on multilocus enzyme electrophoresis and random amplified polymorphic DNA, and subsequently based on the 24S alpha rRNA and mini-exon genes. Recent multilocus enzyme electrophoresis and random amplified polymorphic DNA data have additionally shown that the major multilocus enzyme electrophoresis/random amplified polymorphic DNA lineage II is further subdivided into five smaller lineages, designated IIa-IIe. In this study. the precise correspondence between the multilocus enzyme electrophoresis/random amplified polymorphic DNA and rRNA/mini-exon lineages was investigated. Using the 24S alpha rRNA and mini-exon markers in combination. five sets of strains were distinguished, corresponding to the multilocus enzyme electrophoresis/random amplified polymorphic DNA lineages I, IIa, IIc, IId and to lineages IIb/IIe together, respectively. The previous categorisation into only two primary lineages based on 24S alpha rRNA and mini-exon characterisation is explained, in part, by the lack of representativeness of the breadth of T. cruzi diversity in earlier study samples. Additionally, a PCR assay based on a length-variable region of the 18S rRNA gene distinguished lineage Ile from lineage IIb. Thus, the six multilocus enzyme electrophoresis/random amplified polymorphic DNA lineages could be readily identified by combining data from the 24S alpha rRNA. mini-exon and 18S rRNA characterisation assays, further supporting the relevance of these genetic units for T. cruzi strain classification and subspecific nomenclature. The recently proposed groups T. cruzi I and T. cruzi II correspond to multilocus enzyme electrophoresis/random amplified polymorphic DNA lineages I and IIb, respectively. Our findings show that T cruzi lineage characterisation based on a single marker (either mini-exon or 24S alpha rRNA) has insufficient resolution, and leads to important reinterpretations of recent epidemiological and evolutionary studies based on the oversimplified rRNA/mini-exon dichotomic classification of T cruzi isolates. (C) 2001 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.