B. subtilis is a surface-dwelling bacterium that is competent for natural transformation. Genetically distinct B. subtilis swarms form a boundary upon encounter, mediated by a fast-evolving molecular kin discrimination (KD) system. We here demonstrate that KD-mediated swarm antagonisms in B. subtilis promote transformation-mediated horizontal gene transfer between strains of low relatedness. Gene transfer is largely uni-directional and the result of the induction of competence of the recipient strain by the donor strain is linked to a sigW-mediated stress response. More closely related strains, which in theory would experience more efficient recombination due to increased sequence homology, did not upregulate transformation upon encounter, demonstrating that social interactions can override mechanistic barriers to horizontal gene transfer. KD-mediated competence in response to the encounter of distinct neighbouring strains could maximize the probability of efficient incorporation of novel alleles and genes that have proved to function in a genomically and ecologically similar context.

中文翻译：

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亲缘歧视促进枯草芽孢杆菌无关菌株之间的水平基因转移

枯草芽孢杆菌是一种能自然转化的表面细菌。遗传上不同的枯草芽孢杆菌群在遇到时形成边界，由快速发展的分子亲缘鉴别（KD）系统介导。我们在这里证明枯草芽孢杆菌中KD介导的群体拮抗作用促进低相关性菌株之间转化介导的水平基因转移。基因转移在很大程度上是单向的，供体菌株诱导受体菌株的能力的结果与sigW介导的应激反应有关。从理论上讲，由于序列同源性的提高，更紧密相关的菌株将经历更有效的重组，但它们在遇到后不会上调转化，表明社交互动可以克服水平基因转移的机械性障碍。KD介导的能力，以应对不同的邻近菌株，可以最大程度地有效整合新的等位基因和基因的可能性，这些新等位基因和基因已被证明在基因组学和生态学上相似的环境中发挥作用。