Negative frequency-dependent selection and asymmetrical transformation stabilise multi-strain bacterial population structures.
Negative frequency-dependent selection and asymmetrical transformation stabilise multi-strain bacterial population structures.
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负频率依赖性选择和不对称转化稳定了多菌株细菌群体结构。
DOI：
10.1038/s41396-020-00867-w
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发表时间：
2021-05
期刊：
影响因子：
--
通讯作者：
Croucher NJ
中科院分区：
文献类型：
--
作者：
Harrow GL;Lees JA;Hanage WP;Lipsitch M;Corander J;Colijn C;Croucher NJ
肺炎链球菌可分为许多菌株，每种菌株都是一组不同的分离株，它们共享相似的核心和辅助基因组，并在同一宿主内共同循环。先前的分析表明，肺炎链球菌菌株的短期疫苗相关动态可能是通过多基因座负频率依赖性选择（NFDS）介导的，NFDS将辅助基因座维持在平衡频率。长期模拟表明，NFDS 基于多态性频率、成对遗传距离和系统发育，通过防止漂移造成的变异损失，稳定了克隆进化的多菌株群体。然而，允许在多位点 NFDS 下进化的分离株之间进行对称重组，产生了不同基因型的非结构化群体。当多位点 NFDS 与不对称重组相结合时，观察到的数据的复制得到改善，有利于删除辅助位点而不是插入。这种组合通过远交抑制将种群分成品系，这是由于附属基因组减少的重组体比其亲本基因型的适应性更低。尽管简化的重组模型可能限制了这些模拟像缺乏重组的模型一样准确地维持基因组数据某些特性的能力，但不对称重组和多位点 NFDS 的结合可以从随机初始群体中恢复多菌株群体结构。由于许多细菌抑制插入其染色体，这种组合通常可能是生态位内菌株共存的基础。
Streptococcus pneumoniae can be divided into many strains, each a distinct set of isolates sharing similar core and accessory genomes, which co-circulate within the same hosts. Previous analyses suggested the short-term vaccine-associated dynamics of S. pneumoniae strains may be mediated through multi-locus negative frequency-dependent selection (NFDS), which maintains accessory loci at equilibrium frequencies. Long-term simulations demonstrated NFDS stabilised clonally-evolving multi-strain populations through preventing the loss of variation through drift, based on polymorphism frequencies, pairwise genetic distances and phylogenies. However, allowing symmetrical recombination between isolates evolving under multi-locus NFDS generated unstructured populations of diverse genotypes. Replication of the observed data improved when multi-locus NFDS was combined with recombination that was instead asymmetrical, favouring deletion of accessory loci over insertion. This combination separated populations into strains through outbreeding depression, resulting from recombinants with reduced accessory genomes having lower fitness than their parental genotypes. Although simplistic modelling of recombination likely limited these simulations’ ability to maintain some properties of genomic data as accurately as those lacking recombination, the combination of asymmetrical recombination and multi-locus NFDS could restore multi-strain population structures from randomised initial populations. As many bacteria inhibit insertions into their chromosomes, this combination may commonly underlie the co-existence of strains within a niche.
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影响因子：
5.4
作者：
Croucher NJ;Hanage WP;Harris SR;McGee L;van der Linden M;de Lencastre H;Sá-Leão R;Song JH;Ko KS;Beall B;Klugman KP;Parkhill J;Tomasz A;Kristinsson KG;Bentley SD
通讯作者：
Bentley SD
影响因子：
6.7
作者：
Croucher, Nicholas J.;Harris, Simon R.;Bentley, Stephen D.
通讯作者：
Bentley, Stephen D.
影响因子：
3.3
作者：
Croucher NJ;Chewapreecha C;Hanage WP;Harris SR;McGee L;van der Linden M;Song JH;Ko KS;de Lencastre H;Turner C;Yang F;Sá-Leão R;Beall B;Klugman KP;Parkhill J;Turner P;Bentley SD
通讯作者：
Bentley SD
DOI：
10.1073/pnas.0712019105
发表时间：
2008-09-30
影响因子：
11.1
作者：
Buckee, Caroline O.;Jolley, Keith A.;Maiden, Martin C. J.
通讯作者：
Maiden, Martin C. J.
影响因子：
56.9
作者：
Cobey, Sarah;Lipsitch, Marc
通讯作者：
Lipsitch, Marc