Comparative genomic analysis and phylogenetic position of Theileria equi.
Comparative genomic analysis and phylogenetic position of Theileria equi.
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DOI：
10.1186/1471-2164-13-603
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发表时间：
2012-11-09
期刊：
影响因子：
4.4
通讯作者：
Brayton KA
中科院分区：
文献类型：
--
作者：
Kappmeyer LS;Thiagarajan M;Herndon DR;Ramsay JD;Caler E;Djikeng A;Gillespie JJ;Lau AO;Roalson EH;Silva JC;Silva MG;Suarez CE;Ueti MW;Nene VM;Mealey RH;Knowles DP;Brayton KA
引起疾病并导致死亡或持续感染的节肢动物传播的顶复门寄生虫是对全球人类和动物健康的重大挑战。1901年首次被描述为马梨浆虫，这种重新出现的顶复门寄生虫被重新命名为马巴伯虫，随后被重新命名为马泰勒虫，反映了不确定的分类。了解顶复门寄生虫逃避免疫或化疗消除的机制是开发有效疫苗或化疗药物所必需的。T.马从临床沉默，持续感染的马阻碍了返回美国的目标。S.转为非地方病状态。因此，对T.平等倡议承诺：1）鉴定马属宿主中有助于免疫逃避和持久性的基因，2）鉴定PBMC感染生物学中涉及的基因和3）确定T. equi相对于测序的顶复门寄生虫。发现已知的免疫显性蛋白EMA 1、2和3属于一个10成员基因家族，在成对比较中，平均氨基酸同一性为39%。重要的是，EMA的氨基酸多样性分布在整个蛋白质的长度上。EMA基因的8个同时转录。由于牛泰勒虫病病原体感染并转化宿主细胞PBMC，我们证实T。马感染马PBMC，然而，没有宿主细胞转化的证据。事实上，许多被鉴定为宿主细胞表型的潜在操纵子的基因在T.马基因组比较基因组分析表明，T.马揭示了系统发育定位相对于7 apicomplexan寄生虫使用推导的氨基酸序列从150个基因放置它作为姐妹分类群泰勒虫属。EMA家族不适合经典的抗原变异的范例，我们提出了一个新的模型描述的EMA家族的持久性的作用。T. Equi已经丢失了宿主细胞转化的推定基因，或者这些基因被T. parva和T. annulata后从T.等。我们的分析确定了50个基因，这将是有用的明确的系统发育分类的T。马和密切相关的生物。
Transmission of arthropod-borne apicomplexan parasites that cause disease and result in death or persistent infection represents a major challenge to global human and animal health. First described in 1901 as Piroplasma equi, this re-emergent apicomplexan parasite was renamed Babesia equi and subsequently Theileria equi, reflecting an uncertain taxonomy. Understanding mechanisms by which apicomplexan parasites evade immune or chemotherapeutic elimination is required for development of effective vaccines or chemotherapeutics. The continued risk of transmission of T. equi from clinically silent, persistently infected equids impedes the goal of returning the U. S. to non-endemic status. Therefore comparative genomic analysis of T. equi was undertaken to: 1) identify genes contributing to immune evasion and persistence in equid hosts, 2) identify genes involved in PBMC infection biology and 3) define the phylogenetic position of T. equi relative to sequenced apicomplexan parasites. The known immunodominant proteins, EMA1, 2 and 3 were discovered to belong to a ten member gene family with a mean amino acid identity, in pairwise comparisons, of 39%. Importantly, the amino acid diversity of EMAs is distributed throughout the length of the proteins. Eight of the EMA genes were simultaneously transcribed. As the agents that cause bovine theileriosis infect and transform host cell PBMCs, we confirmed that T. equi infects equine PBMCs, however, there is no evidence of host cell transformation. Indeed, a number of genes identified as potential manipulators of the host cell phenotype are absent from the T. equi genome. Comparative genomic analysis of T. equi revealed the phylogenetic positioning relative to seven apicomplexan parasites using deduced amino acid sequences from 150 genes placed it as a sister taxon to Theileria spp. The EMA family does not fit the paradigm for classical antigenic variation, and we propose a novel model describing the role of the EMA family in persistence. T. equi has lost the putative genes for host cell transformation, or the genes were acquired by T. parva and T. annulata after divergence from T. equi. Our analysis identified 50 genes that will be useful for definitive phylogenetic classification of T. equi and closely related organisms.
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影响因子：
5.3
作者：
Bishop, R;Musoke, A;Gobright, E
通讯作者：
Gobright, E
影响因子：
2.6
作者：
Freeman, Jeanne M.;Kappmeyer, Lowell S.;Knowles, Donald P.
通讯作者：
Knowles, Donald P.
影响因子：
1.5
作者：
Florin-Christensen, J;Suarez, CE;Palmer, GH
通讯作者：
Palmer, GH
影响因子：
--
作者：
Ferguson, David J. P.;Sahoo, Nivedita;Gubbels, Marc-Jan
通讯作者：
Gubbels, Marc-Jan
影响因子：
12.3
作者：
Allen JE;Majoros WH;Pertea M;Salzberg SL
通讯作者：
Salzberg SL