Recombination and population structure in Salmonella enterica.
Recombination and population structure in Salmonella enterica.
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DOI：
10.1371/journal.pgen.1002191
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发表时间：
2011-07
期刊：
影响因子：
4.5
通讯作者：
Donnelly P
中科院分区：
文献类型：
--
作者：
Didelot X;Bowden R;Street T;Golubchik T;Spencer C;McVean G;Sangal V;Anjum MF;Achtman M;Falush D;Donnelly P
肠沙门氏菌是一种细菌性病原体，可引起人和动物的肠热病和胃肠炎。虽然其种群结构长期以来被描述为克隆，但基于酶电泳法分型的基因座之间的高度连锁不平衡，最近对基因序列的检测表明，重组在进化中起着重要的作用。我们使用重测序微阵列对114株肠杆菌的核心基因组进行了大约10%的测序。对我们的基因组数据应用两种不同的分析方法(结构和克隆框架)使我们能够在肠杆菌亚种ENTERICA中确定五个明确的谱系，其中一个比另外四个和整个亚种年龄的三分之二老五倍。我们发现，这些血统中的一些比其他血统显示出更多的重组证据。我们还证明了在血统之间存在一定程度的性隔离，因此重组主要发生在同一血统的成员之间。这种重组模式与前面描述的肠道种群生态结构的预期以及实验室实验中观察到的重组的机械障碍是一致的。尽管它们的遗传分化水平相对较低，但这些谱系可能因此代表了早期物种。肠沙门氏菌是一种能引起人类和动物严重疾病的细菌。我们从广泛抽样的肠杆菌集合中对大约十分之一的基因组进行了测序。通过比较这些基因序列，我们能够部分重建这个样本的祖先。我们在肠杆菌中鉴定了五个谱系，其中一个几乎和我们样本的共同祖先一样古老。我们还发现了肠链球菌祖先中频繁同源重组的证据，其中来自一种单个细菌的基因片段被另一个不同的个体获得。这些重组事件使整个祖先的重建变得更加困难，但也包含了有趣的信息。我们特别发现，属于同一谱系的菌株之间的重组发生得更频繁，而不是跨越谱系边界。这一观察结果与肠链球菌的谱系逐渐相互隔离是一致的，这可能会导致它们逐渐分裂成新的物种。
Salmonella enterica is a bacterial pathogen that causes enteric fever and gastroenteritis in humans and animals. Although its population structure was long described as clonal, based on high linkage disequilibrium between loci typed by enzyme electrophoresis, recent examination of gene sequences has revealed that recombination plays an important evolutionary role. We sequenced around 10% of the core genome of 114 isolates of enterica using a resequencing microarray. Application of two different analysis methods (Structure and ClonalFrame) to our genomic data allowed us to define five clear lineages within S. enterica subspecies enterica, one of which is five times older than the other four and two thirds of the age of the whole subspecies. We show that some of these lineages display more evidence of recombination than others. We also demonstrate that some level of sexual isolation exists between the lineages, so that recombination has occurred predominantly between members of the same lineage. This pattern of recombination is compatible with expectations from the previously described ecological structuring of the enterica population as well as mechanistic barriers to recombination observed in laboratory experiments. In spite of their relatively low level of genetic differentiation, these lineages might therefore represent incipient species. Salmonella enterica is a species of bacteria that causes severe diseases in humans and animals. We sequenced about a tenth of the genome from a broadly sampled collection of S. enterica. By comparing these genetic sequences, we were able to partially reconstruct the ancestry of this sample. We identified five lineages within S. enterica, one of which is almost as old as the common ancestor of our sample. We also found evidence for frequent homologous recombination in the ancestry of S. enterica, where fragments of genes from one individual bacterium are acquired by a distinct individual. These recombination events make the ancestry harder to reconstruct in its entirety, but also contain interesting information. We found in particular that recombination had happened more often between strains belonging to the same lineage than across lineage boundaries. This observation is compatible with the lineages of S. enterica becoming progressively isolated from each other, which could lead to their gradual splintering into new species.
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影响因子：
64.8
作者：
Buckling, A;Rainey, PB
通讯作者：
Rainey, PB
影响因子：
3.3
作者：
Didelot, Xavier;Falush, Daniel
通讯作者：
Falush, Daniel
DOI：
10.1099/00221287-137-3-601
发表时间：
1991-03-01
期刊：
JOURNAL OF GENERAL MICROBIOLOGY
影响因子：
--
作者：
BELTRAN, P;PLOCK, SA;SELANDER, RK
通讯作者：
SELANDER, RK
影响因子：
2
作者：
BAINS, W;SMITH, GC
通讯作者：
SMITH, GC
影响因子：
14.9
作者：
Chiu CH;Tang P;Chu C;Hu S;Bao Q;Yu J;Chou YY;Wang HS;Lee YS
通讯作者：
Lee YS