One of the hallmark behaviors of social groups is division of labor, where different group members become specialized to carry out complementary tasks. By dividing labor, cooperative groups increase efficiency, thereby raising group fitness even if these behaviors reduce individual fitness. We find that antibiotic production in colonies of Streptomyces coelicolor is coordinated by a division of labor. We show that S. coelicolor colonies are genetically heterogeneous because of amplifications and deletions to the chromosome. Cells with chromosomal changes produce diversified secondary metabolites and secrete more antibiotics; however, these changes reduced individual fitness, providing evidence for a trade-off between antibiotic production and fitness. Last, we show that colonies containing mixtures of mutants and their parents produce significantly more antibiotics, while colony-wide spore production remains unchanged. By generating specialized mutants that hyper-produce antibiotics, streptomycetes reduce the fitness costs of secreted secondary metabolites while maximizing the yield and diversity of these products.

中文翻译：

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链霉菌中的抗生素生产是通过末端基因组分化来分工组织的。

社会团体的标志性行为之一是分工，其中不同的团体成员变得专门从事补充任务。通过分工，合作团体可以提高效率，从而提高团体适应度，即使这些行为降低了个人适应度。我们发现，在产链霉菌的菌落中，抗生素的生产受到分工的协调。我们显示S. coelicolor殖民地是遗传异质的，因为染色体的扩增和缺失。具有染色体变化的细胞可产生多种次生代谢产物，并分泌更多抗生素。然而，这些变化降低了个体适应性，为抗生素生产与适应性之间的权衡提供了证据。持续，我们显示，含有突变体及其亲本混合物的菌落产生的抗生素明显更多，而菌落范围内的孢子产量保持不变。通过产生高产抗生素的专门突变体，链霉菌降低了分泌的次级代谢产物的适应性成本，同时使这些产品的产量和多样性最大化。