Pleiotropic mutations can rapidly evolve to directly benefit self and cooperative partner despite unfavorable conditions.
Pleiotropic mutations can rapidly evolve to directly benefit self and cooperative partner despite unfavorable conditions.
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作者：
Hart SFM;Chen CC;Shou W
付出代价以造福他人的合作十分普遍。合作可以通过直接有利于自我（自我服务）和伙伴（伙伴服务）的多效性“双赢”突变来促进。以前，我们表明，合作伙伴服务应被定义为增加的利益供给率每摄入量的好处。在这里，我们报告说，即使在不利于合作的条件下，双赢的突变也能迅速进化。具体来说，在一个良好的混合环境中，我们进化出了工程酵母合作社区，其中两种菌株交换了昂贵的代谢产物，赖氨酸和次黄嘌呤。在消耗赖氨酸并释放次黄嘌呤的细胞中，ecm21突变反复出现。ecm21是自我服务的，在限制赖氨酸的情况下提高自身的生长速率。ECM 21也是伴侣服务的，增加每次赖氨酸消耗的次黄嘌呤释放速率以及伴侣和群体的稳态生长速率。ECM 21也出现在赖氨酸限制的恒化器中进化的单培养物中。因此，即使没有任何合作的历史或维持合作的压力，多效性双赢突变也可能很容易地进化以促进合作。
Cooperation, paying a cost to benefit others, is widespread. Cooperation can be promoted by pleiotropic ‘win-win’ mutations which directly benefit self (self-serving) and partner (partner-serving). Previously, we showed that partner-serving should be defined as increased benefit supply rate per intake benefit. Here, we report that win-win mutations can rapidly evolve even under conditions unfavorable for cooperation. Specifically, in a well-mixed environment we evolved engineered yeast cooperative communities where two strains exchanged costly metabolites, lysine and hypoxanthine. Among cells that consumed lysine and released hypoxanthine, ecm21 mutations repeatedly arose. ecm21 is self-serving, improving self’s growth rate in limiting lysine. ecm21 is also partner-serving, increasing hypoxanthine release rate per lysine consumption and the steady state growth rate of partner and of community. ecm21 also arose in monocultures evolving in lysine-limited chemostats. Thus, even without any history of cooperation or pressure to maintain cooperation, pleiotropic win-win mutations may readily evolve to promote cooperation.