Experimental evolution of selfish policing in social bacteria
Experimental evolution of selfish policing in social bacteria
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DOI：
10.1073/pnas.1014695108
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发表时间：
2011-05-17
影响因子：
11.1
通讯作者：
Velicer, Gregory J.
中科院分区：
文献类型：
--
作者：
Manhes, Pauline;Velicer, Gregory J.
合作的有机体在社会多样性的种群中进化。在既有合作者又有作弊者的群体中，合作者可能会通过与其中一种社会类型或两者的新互动来适应。当合作对适应性很重要时，不同的动物特征会抑制自私行为，但原核生物进化出这种特征的潜力尚不清楚。我们让一种擅长合作子实体发育的细菌粘球菌（Myxococcus xanthus）进化，同时反复遇到一个不进化的发育骗子。进化中的种群在作弊者的存在下大大增加了它们的适应性，无论是相对于它们的祖先还是绝对孢子生产力。然而，在作弊者缺席的情况下，同样进化的血统对祖先表现出净劣势。不断进化的种群将作弊者的一个巨大的祖先劣势转化为竞争优势，并进化为强烈抑制作弊者的生产力。此外，在有作弊者的三方混合中，相对于只有祖先和作弊者的混合，进化后的种群提高了祖先的生产力。因此，我们的进化群体就像自私的警察一样，为了自己的利益和他人的利益，抑制作弊者。作弊者抑制在多个不熟悉的作弊者中普遍存在，但对进化上熟悉的作弊者更为明显。此外，进化产生了三种新的互利关系，包括进化细胞和选择机制作弊者之间的互补缺陷拯救。这里记录的作弊者抑制的快速进化表明，原核生物自然种群中共同进化的社会策略比以前认识的更加多样和复杂。
Cooperative organisms evolve within socially diverse populations. In populations harboring both cooperators and cheaters, cooperators might adapt by evolving novel interactions with either social type or both. Diverse animal traits suppress selfish behaviors when cooperation is important for fitness, but the potential for prokaryotes to evolve such traits is unclear. We allowed a strain of the bacterium Myxococcus xanthus that is proficient at cooperative fruiting body development to evolve while repeatedly encountering a non-evolving developmental cheater. Evolving populations greatly increased their fitness in the presence of the cheater, both relative to their ancestor and in terms of absolute spore productivity. However, the same evolved lineages exhibited a net disadvantage to the ancestor in the cheater's absence. Evolving populations reversed a large ancestral disadvantage to the cheater into competitive superiority and also evolved to strongly suppress cheater productivity. Moreover, in three-party mixes with the cheater, evolved populations enhanced their ancestor's productivity relative to mixes of only the ancestor and cheater. Thus, our evolved populations function as selfish police that inhibit cheaters, both to their own advantage and to the benefit of others as well. Cheater suppression was general across multiple unfamiliar cheaters but was more pronounced against the evolutionarily familiar cheater. Also, evolution generated three new mutually beneficial relationships, including complementary defect rescue between evolved cells and the selection-regime cheater. The rapid evolution of cheater suppression documented here suggests that coevolving social strategies within natural populations of prokaryotes are more diverse and complex than previously appreciated.