Evolution and diversity of Rickettsia bacteria.
Evolution and diversity of Rickettsia bacteria.
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DOI：
10.1186/1741-7007-7-6
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发表时间：
2009-02-02
期刊：
影响因子：
5.4
通讯作者：
Jiggins FM
中科院分区：
文献类型：
--
作者：
Weinert LA;Werren JH;Aebi A;Stone GN;Jiggins FM
立克次体是真核生物的细胞内共生体，最为人所知的是感染人类和其他哺乳动物并导致严重疾病。所有已知的脊椎动物相关立克次体都是由节肢动物作为其生活史的一部分进行媒介传播的，许多其他立克次体只在节肢动物中发现，没有已知的第二宿主。然而，人们对后一种菌株的生物学知之甚少。在此，我们从节肢动物中鉴定了20个新立克次体菌株，并构建了包括这些新菌株在内的整个属的多基因系统发育图。我们证明立克次体主要是与节肢动物相关的细菌，并在该属中鉴定了几个新的类群。立克次体不与寄主共种，但寄主转移最常发生在相关节肢动物之间。立克次体已经进化出适应能力，包括通过脊椎动物传播和在一些节肢动物宿主中杀死雄性。我们发现了一个在立克次体之间水平基因转移的案例，其中一个菌株是来自两个远亲群体的嵌合体，但多基因分析表明，基因组的不同部分往往具有相同的系统发育。大约1.5亿年前，立克次体分裂成两个主要分支，一个主要感染节肢动物，另一个感染各种原生动物、其他真核生物和节肢动物。大约5000万年前发生了一次迅速的辐射，这与生活史适应的进化在系统发育的几个分支中是一致的。尽管立克次体被认为主要是垂直传播的，但寄主关联是短暂的，频繁地切换到新的寄主谱系。尽管有证据表明有水平的基因转移，但整个属的重组通常是不常见的。更好地了解立克次体的进化将有助于阐明致病、传播和毒力的机制。
Rickettsia are intracellular symbionts of eukaryotes that are best known for infecting and causing serious diseases in humans and other mammals. All known vertebrate-associated Rickettsia are vectored by arthropods as part of their life-cycle, and many other Rickettsia are found exclusively in arthropods with no known secondary host. However, little is known about the biology of these latter strains. Here, we have identified 20 new strains of Rickettsia from arthropods, and constructed a multi-gene phylogeny of the entire genus which includes these new strains. We show that Rickettsia are primarily arthropod-associated bacteria, and identify several novel groups within the genus. Rickettsia do not co-speciate with their hosts but host shifts most often occur between related arthropods. Rickettsia have evolved adaptations including transmission through vertebrates and killing males in some arthropod hosts. We uncovered one case of horizontal gene transfer among Rickettsia, where a strain is a chimera from two distantly related groups, but multi-gene analysis indicates that different parts of the genome tend to share the same phylogeny. Approximately 150 million years ago, Rickettsia split into two main clades, one of which primarily infects arthropods, and the other infects a diverse range of protists, other eukaryotes and arthropods. There was then a rapid radiation about 50 million years ago, which coincided with the evolution of life history adaptations in a few branches of the phylogeny. Even though Rickettsia are thought to be primarily transmitted vertically, host associations are short lived with frequent switching to new host lineages. Recombination throughout the genus is generally uncommon, although there is evidence of horizontal gene transfer. A better understanding of the evolution of Rickettsia will help in the future to elucidate the mechanisms of pathogenicity, transmission and virulence.
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影响因子：
4.5
作者：
Dunning Hotopp JC;Lin M;Madupu R;Crabtree J;Angiuoli SV;Eisen JA;Seshadri R;Ren Q;Wu M;Utterback TR;Smith S;Lewis M;Khouri H;Zhang C;Niu H;Lin Q;Ohashi N;Zhi N;Nelson W;Brinkac LM;Dodson RJ;Rosovitz MJ;Sundaram J;Daugherty SC;Davidsen T;Durkin AS;Gwinn M;Haft DH;Selengut JD;Sullivan SA;Zafar N;Zhou L;Benahmed F;Forberger H;Halpin R;Mulligan S;Robinson J;White O;Rikihisa Y;Tettelin H
通讯作者：
Tettelin H
影响因子：
3.7
作者：
Gillespie, Joseph J.;Williams, Kelly;Shukla, Maulik;Snyder, Eric E.;Nordberg, Eric K.;Ceraul, Shane M.;Dharmanolla, Chitti;Rainey, Daphne;Soneja, Jeetendra;Shallom, Joshua M.;Vishnubhat, Nataraj Dongre;Wattam, Rebecca;Purkayastha, Anjan;Czar, Michael;Crasta, Oswald;Setubal, Joao C.;Azad, Abdu F.;Sobral, Bruno S.
通讯作者：
Sobral, Bruno S.
影响因子：
10.7
作者：
Bryant, D;Moulton, V
通讯作者：
Moulton, V
影响因子：
4.4
作者：
Baldridge, Gerald D.;Burkhardt, Nicole Y.;Munderloh, Ulrike G.
通讯作者：
Munderloh, Ulrike G.
影响因子：
2.6
作者：
Baldo, Laura;Werren, John H.
通讯作者：
Werren, John H.