Estimating the relative contributions of mutation and recombination to clonal diversification:: a comparison between Neisseria meningitidis and Streptococcus pneumoniae
Estimating the relative contributions of mutation and recombination to clonal diversification:: a comparison between Neisseria meningitidis and Streptococcus pneumoniae
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DOI：
10.1016/s0923-2508(00)00168-6
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发表时间：
2000-07-01
影响因子：
2.6
通讯作者：
Spratt, BG
中科院分区：
文献类型：
--
作者：
Feil, EJ;Enright, MC;Spratt, BG
脑膜炎奈瑟氏菌和肺炎链球菌都是自然转化的物种，并已知在野外自由重组。已经为这些物种生成了大型多位点序列分型(MLST)数据集。在这里，我们概述了一种方法，它利用这些数据集来量化重组的程度，从而能够在两个物种之间进行有意义的比较。估计了两个参数：与点突变相比，重组改变等位基因的速度；与点突变相比，重组改变单个核苷酸位点的速度。对前一个参数的估计在脑膜炎球菌中为4：1(即等位基因通过重组比突变改变的频率高出四倍)，在肺炎球菌中为10：1。然而，对后一个参数的估计在脑膜炎球菌中至少为80：1(即单个核苷酸位置通过重组至少比通过突变改变的可能性高80倍)，在肺炎球菌中为50：1。这些数据表明，与突变事件相比，重组事件在肺炎球菌中可能比在脑膜炎球菌中更常见。然而，因为它是一个更多样化的物种，脑膜炎球菌中的每一次重组交换平均会导致更多的核苷酸变化。(C)2000年版《爱思唯尔科学与医学》。
Both Neisseria meningitidis and Streptococcus pneumoniae are naturally transformable species and are known to be freely recombining in the wild. Large multilocus sequence typing (MLST) datasets have been generated for these species. Here we outline an approach which exploits these data sets in order to quantify the extent of recombination, thus enabling meaningful comparisons between the two species. Two parameters are estimated; the rate at which recombination changes alleles, compared to point mutation, and the rate at which recombination changes individual nucleotide sites, compared to point mutation. Estimates for the former parameter are 4:1 in the meningococcus (i.e. alleles are changed four-fold more frequently by recombination than by mutation), and 10:1 in the pneumococcus. However, estimates for the latter parameter are at least 80:1 in the meningococcus (i.e. an individual nucleotide site is at least 80-fold more likely to change by recombination than by mutation) and 50:1 in the pneumococcus. These data imply that recombination events, compared to mutational events, may be more common in the pneumococcus than in the meningococcus. However, because it is a more diverse species, each recombinational exchange in the meningococcus results in more nucleotide changes on average. (C) 2000 Editions scientifiques et medicales Elsevier SAS.