Genetic variation of dTDP-L-rhamnose pathway genes in Salmonella enterica
Genetic variation of dTDP-L-rhamnose pathway genes in Salmonella enterica
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DOI：
10.1099/00221287-146-9-2291
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发表时间：
2000-09-01
期刊：
影响因子：
--
通讯作者：
Reeves, PR
中科院分区：
文献类型：
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作者：
Li, Q;Reeves, PR
在enterica沙门氏菌中DTDP-L-RHAMNOSE途径基因集（RMLB，RMLD，RMLA，RMLC）的遗传变异后，在对编码7种O抗原的11个含RML基因簇的四个基因进行测序后，检查了四个基因。还有另外23个代表七个亚种的23个菌株的903 bp rmlb段。 RML基因之间的性质和变异水平（RML基因集的5'末端）（包括RMLB，RMLD和大多数RMLA）之间存在很大的序列变化和强极性。通常是特定于亚种的。相反，包括RMLA和所有RMLC在内的3'端是抗原特异性的。 3'端的G + C含量低于5'端的含量。基因集的3'末端的变化大大远大于5'端的变化。显然，肠链球菌的RML基因集包含具有两个不同进化史的基因。另外，该基因集已经进行了广泛的重组，可能与亚种之间的O抗原转移有关。这些发现提供了O抗原基因在物种之间以及肠链球菌亚种之间的横向转移的证据。结果还表明，在O抗原基因簇结束时，保守基因在介导中央血清群特异性区域的交换中起主要作用。
The genetic variation in the dTDP-L-rhamnose pathway gene set (rmlB, rmlD, rmlA, rmlC) in Salmonella enterica was examined after sequencing the four genes from 11 rml-containing gene clusters encoding seven O antigens. and a 903 bp rmlB segment from another 23 strains representing the seven subspecies. There was considerable sequence variation and strong polarity in the nature and level of variation among rml genes, the 5' end of the rml gene set, including rmlB, rmlD and most of rmlA. is in general subspecies specific. In contrast, the 3' end, including part of rmlA and all of rmlC, is O antigen specific. The G + C content of the 3' end is lower than that of the 5' end. The variation in the 3' end of the gene set is much greater than that of the 5' end. It is apparent that the rml gene set of S. enterica includes genes with two different evolutionary histories. In addition, there has been extensive recombination in the gene set, probably related to O antigen transfer between subspecies. These findings provide evidence for the lateral transfer of O antigen genes between species and among subspecies of S. enterica. The results have also shown that conserved genes at the end of an O antigen gene cluster play a major role in mediating exchange of the central serogroup-specific regions.