Genetic diversity of Trypanosoma cruzi in bats, and multilocus phylogenetic and phylogeographical analyses supporting Tcbat as an independent DTU (discrete typing unit)
Genetic diversity of Trypanosoma cruzi in bats, and multilocus phylogenetic and phylogeographical analyses supporting Tcbat as an independent DTU (discrete typing unit)
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DOI：
10.1016/j.actatropica.2015.07.015
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发表时间：
2015-11-01
期刊：
影响因子：
2.7
通讯作者：
Teixeira, Marta M. G.
中科院分区：
文献类型：
--
作者：
Lima, Luciana;Espinosa-Alvarez, Oneida;Teixeira, Marta M. G.
克氏锥虫是一个复杂的表型和遗传多样性的分离株分布在六个离散的分型单位（DTU）指定为TcI-TcVI。五年前，T。来自巴西蝙蝠的克氏分离物显示出传统核糖体和剪接前导PCR的独特模式，不聚类到六个DTU中的任何一个中，被指定为Tcbat基因型。在本研究中，使用SSU rRNA（核糖体rRNA的小亚基），gGAPDH（糖体甘油醛3-磷酸脱氢酶）和CytB（细胞色素B）基因推断的遗传学强烈支持Tcbat作为巴西，巴拿马和哥伦比亚流行的单系谱系。为Tcbat提供强有力的支持，来自47个核和12个线粒体中的37个序列！基因（从Tcbat的基因组草图中检索）和数据库中所有DTU的参考菌株证实Tcbat是独立的DTU。与以前的研究一致，大多数核基因的多位点分析证实了T。cruzi从蝙蝠锥虫其分歧成两个主要的系统发育谱系：基础TcII和谱系聚类TcIV，分支包括TcIII和姐妹组TcI-Tcbat。最有可能的是，Tcbat和TcI的共同祖先是蝙蝠锥虫。然而，目前的分析结果并不支持Tcbat作为所有DTU的祖先。尽管TcIII，TcIV和TcII在蝙蝠，包括亚马逊蝙蝠窝藏TcII的报告提供的见解，进一步的研究是必要的，以了解蝙蝠在所有DTU的多样化所发挥的作用。我们还表明，除了作为DTU分配的分子标记的价值，Cytb，ITS rDNA和剪接的前导（SL）多态性序列表明Tcbat的空间结构的人口。系统发育和地理分布分析，多个分子标记的Tcbat，和Tcbat和公认的DTU之间的序列分歧的程度强烈支持Tcbat作为一个新的DTU的明确分类。(C)2015 Elsevier B. V.版权所有。
Trypanosoma cruzi is a complex of phenotypically and genetically diverse isolates distributed in six discrete typing units (DTUs) designated as TcI-TcVI. Five years ago, T. cruzi isolates from Brazilian bats showing unique patterns of traditional ribosomal and spliced leader PCRs not clustering into any of the six DTUs were designated as the Tcbat genotype. In the present study, phylogenies inferred using SSU rRNA (small subunit of ribosomal rRNA), gGAPDH (glycosomal glyceraldehyde 3-phosphate dehydrogenase) and Cytb (cytochrome b) genes strongly supported Tcbat as a monophyletic lineage prevalent in Brazil, Panama and Colombia. Providing strong support for Tcbat, sequences from 37 of 47 nuclear and 12 mitochondria! genes (retrieved from a draft genome of Tcbat) and reference strains of all DTUs available in databanks corroborated Tcbat as an independent DTU. Consistent with previous studies, multilocus analysis of most nuclear genes corroborated the evolution of T. cruzi from bat trypanosomes its divergence into two main phylogenetic lineages: the basal TcII; and the lineage clustering TcIV, the clade comprising TcIII and the sister groups TcI-Tcbat. Most likely, the common ancestor of Tcbat and TcI was a bat trypanosome. However, the results of the present analysis did not support Tcbat as the ancestor of all DTUs. Despite the insights provided by reports of TcIII, TcIV and TcII in bats, including Amazonian bats harbouring TcII, further studies are necessary to understand the roles played by bats in the diversification of all DTUs. We also demonstrated that in addition to value as molecular markers for DTU assignment, Cytb, ITS rDNA and the spliced leader (SL) polymorphic sequences suggest spatially structured populations of Tcbat. Phylogenetic and phylogeographical analyses, multiple molecular markers specific to Tcbat, and the degrees of sequence divergence between Tcbat and the accepted DTUs strongly support the definitive classification of Tcbat as a new DTU. (C) 2015 Elsevier B.V. All rights reserved.