Dissecting the phyloepidemiology of Trypanosoma cruzi I (TcI) in Brazil by the use of high resolution genetic markers.
Dissecting the phyloepidemiology of Trypanosoma cruzi I (TcI) in Brazil by the use of high resolution genetic markers.
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DOI：
10.1371/journal.pntd.0006466
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发表时间：
2018-05
影响因子：
3.8
通讯作者：
Yeo M
中科院分区：
文献类型：
--
作者：
Roman F;das Chagas Xavier S;Messenger LA;Pavan MG;Miles MA;Jansen AM;Yeo M
克氏锥虫是恰加斯病的病原体，它是单系的，但在遗传上是异质性的。它目前由六个遗传谱系(离散分型单位，DTU)代表，命名为TCI-TcVI。TCI是地理分布最广、遗传差异最大的谱系，广泛应用于拉丁美洲广泛地理范围的分离株的遗传标记证明了这一点。利用6个核看家基因、25个微卫星座位和1个线粒体标记对从巴西5个不同生物群的寄主和媒介分离的78个TCI进行了分析。核标记显示了大量的遗传多样性、生物群间显著的基因流动、系统发育中的不一致，以及指示DTU内遗传交换的单倍型分析。基于线粒体和核基因座的系统发育重建不一致，与渐渗一致。微卫星数据的结构分析显示，在生物群中，亚马逊地区的遗传多样性最高，基因流动水平最低。以寄主种类/属为基础的种群结构调查表明，袋生毛滴虫可能是TCI的主要传播者。目前的工作考虑了来自巴西不同宿主和媒介的大量TCI样本，这些样本跨越了巴西多个生态多样化的生物群。重要的是，我们结合了快速和缓慢进化的标记，有助于在五个不同的巴西生物群中对TCI的动物行为学理解。这是首次将MLST分析与MLMT和Maxicircle标记相结合来评估巴西TCI分离株的遗传多样性。我们的结果证明了大量遗传多样性的存在和导入事件的发生。我们提供了巴西TCI分离株之间基因交换的证据，以及亚马逊生物群中TCI相对隔离的证据。我们观察到，TCI基因型与地理区域和/或宿主物种之间没有严格的关联。克氏锥虫是一种感染哺乳动物的人畜共患原生动物寄生虫，广泛分布于拉丁美洲地方病流行地区。众所周知，它具有相当大的遗传多样性，包括六个离散的遗传谱系，指定为离散分型单位(DTU)TCI-TcVI。TCI是基因最多样化的DTU，也是巴西样本最多的血统。我们使用高分辨率分子技术的组合来分析巴西TCI分离株的遗传多样性，这些分离株来自广泛的地理区域，包括从不同哺乳动物宿主和昆虫媒介分离的五个不同的生物群。结果显示显著的遗传多样性，并且没有明显的基因类型与地区或宿主/媒介物种的关联。来自基于核和线粒体标记的不一致的系统发育拓扑的证据表明，遗传交换和/或导入事件。讨论了这些发现在种群结构、生态学和动物学背景下的相关性。
Trypanosoma cruzi, the causal agent of Chagas disease, is monophyletic but genetically heterogeneous. It is currently represented by six genetic lineages (Discrete Typing Units, DTUs) designated TcI-TcVI. TcI is the most geographically widespread and genetically heterogeneous lineage, this as is evidenced by a wide range of genetic markers applied to isolates spanning a vast geographic range in Latin America. In total, 78 TcI isolated from hosts and vectors distributed in 5 different biomes of Brazil, were analyzed using 6 nuclear housekeeping genes, 25 microsatellite loci and one mitochondrial marker. Nuclear markers reveal substantial genetic diversity, significant gene flow between biomes, incongruence in phylogenies, and haplotypic analysis indicative of intra-DTU genetic exchange. Phylogenetic reconstructions based on mitochondrial and nuclear loci were incongruent, and consistent with introgression. Structure analysis of microsatellite data reveals that, amongst biomes, the Amazon is the most genetically diverse and experiences the lowest level of gene flow. Investigation of population structure based on the host species/genus, indicated that Didelphis marsupialis might play a role as the main disperser of TcI. The present work considers a large TcI sample from different hosts and vectors spanning multiple ecologically diverse biomes in Brazil. Importantly, we combine fast and slow evolving markers to contribute to the epizootiological understanding of TcI in five distinct Brazilian biomes. This constitutes the first instance in which MLST analysis was combined with the use of MLMT and maxicircle markers to evaluate the genetic diversity of TcI isolates in Brazil. Our results demonstrate the existence of substantial genetic diversity and the occurrence of introgression events. We provide evidence of genetic exchange in TcI isolates from Brazil and of the relative isolation of TcI in the Amazon biome. We observe the absence of strict associations with TcI genotypes to geographic areas and/or host species. T. cruzi is a zoonotic protozoan parasite infecting mammals and widely dispersed throughout endemic Latin America. It is known to possess considerable genetic diversity, comprising six discrete genetic lineages designated Discrete Typing Units (DTUs) TcI-TcVI. TcI is the most genetically diverse DTU and the most frequently sampled lineage in Brazil. We use a combination of high resolution molecular techniques to analyze the genetic diversity of Brazilian TcI isolates obtained from a wide geographical area encompassing five distinct biomes isolated from different mammal hosts and insect vectors. The results reveal significant genetic diversity and no clear association of genotypes with areas or host/vector species. Evidence from incongruent phylogenetic topologies based on nuclear and mitochondrial markers are indicative of genetic exchange and/or introgression events. The relevance of these findings in the context of population structure, ecology and epizootiology is discussed.
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DOI：
10.1590/s0074-02762007005000098
发表时间：
2007-10-01
期刊：
Memórias do Instituto Oswaldo Cruz
影响因子：
--
作者：
Aguilar, Hugo Marcelo;Abad-Franch, Fernando;Coura, José Rodrigues
通讯作者：
Coura, José Rodrigues
影响因子：
3.7
作者：
Cottontail, Veronika M.;Kalko, Elisabeth K. V.;Miguel Pinto, C.
通讯作者：
Miguel Pinto, C.
影响因子：
2
作者：
Brandao, Adeilton;Samudio, Franklyn;Sousa, Octavio E.
通讯作者：
Sousa, Octavio E.
影响因子：
2.6
作者：
Excoffier, Laurent;Laval, Guillaume;Schneider, Stefan
通讯作者：
Schneider, Stefan
影响因子：
2.7
作者：
Alarcon de Noya, Belkisyole;Gonzalez, Oscar Noya
通讯作者：
Gonzalez, Oscar Noya