Cooperation and cheating are widespread evolutionary strategies. While cheating confers an advantage to individual entities within a group, competition between groups favors cooperation. Selfish or cheater mitochondrial DNA (mtDNA) proliferates within hosts while being selected against at the level of host fitness. How does environment shape cheater dynamics across different selection levels? Focusing on food availability, we address this question using heteroplasmic Caenorhabditis elegans. We find that the proliferation of selfish mtDNA within hosts depends on nutrient status stimulating mtDNA biogenesis in the developing germline. Interestingly, mtDNA biogenesis is not sufficient for this proliferation, which also requires the stress-response transcription factor FoxO/DAF-16. At the level of host fitness, FoxO/DAF-16 also prevents food scarcity from accelerating the selection against selfish mtDNA. This suggests that the ability to cope with nutrient stress can promote host tolerance of cheaters. Our study delineates environmental effects on selfish mtDNA dynamics at different levels of selection.

中文翻译：

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营养状况在不同的选择水平上塑造了自私的线粒体基因组动态

合作和欺骗是普遍的进化策略。欺骗为群体内的个体实体带来优势，而群体之间的竞争则有利于合作。自私或作弊的线粒体 DNA (mtDNA) 在宿主体内增殖，同时在宿主健康水平上被选择。环境如何影响不同选择级别的作弊者动态？着眼于食物供应，我们使用异质秀丽隐杆线虫来解决这个问题。我们发现宿主内自私 mtDNA 的增殖取决于刺激发育中的生殖系中 mtDNA 生物发生的营养状况。有趣的是，mtDNA 生物发生不足以实现这种增殖，这还需要应激反应转录因子 FoxO/DAF-16。在宿主健康水平上，FoxO/DAF-16 还可以防止食物短缺加速对自私 mtDNA 的选择。这表明应对营养压力的能力可以促进宿主对欺骗者的耐受性。我们的研究描绘了在不同选择水平下环境对自私 mtDNA 动力学的影响。