Enhancement of K-strategy evolution in histidine utilization using a container with compartments
Enhancement of K-strategy evolution in histidine utilization using a container with compartments
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使用带隔室的容器增强组氨酸利用中的 K 策略进化
DOI：
10.1111/gtc.12640
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发表时间：
2018
期刊：
影响因子：
2.1
通讯作者：
Tsuru Saburo
中科院分区：
文献类型：
--
作者：
Komori Takahiro;Shibai Atsushi;Saito Hiromi;Akeno Yuya;Germond Arno;Horinouchi Takaaki;Furusawa Chikara;Tsuru Saburo
增长改进中的进化策略可以分为r-或K-策略。前一种策略对应于增长率的进化增加，而后者对应于生物体最大数量或承载能力的增加。是什么决定了在进化过程中采取的策略？将种群划分为小块的空间结构是诱导K策略的关键。有趣的是，先前在葡萄糖限制的分批培养中使用大肠杆菌的进化实验表明，即使在没有空间结构的情况下，承载能力也可以进化性地提高。然而，目前尚不清楚，如果缺乏空间结构可以直接演变为高承载能力的利用其他资源。为了解决这个问题，我们建立了一个简化的进化实验，在组氨酸限制条件下，在一个有隔室的容器中使用需要组氨酸的大肠杆菌。我们证实了空间结构在组氨酸利用的K策略进化中的重要性。K适应菌株的全基因组测序显示了在适应性增加期间突变基因的功能多样性。这些结果验证了空间结构的重要性，并暗示K策略进化对某种营养素的限制是由于缺乏适当的选择，而不是缺乏因果突变。
Evolutionary strategies in growth improvement can be classified into r‐ or K‐strategies. The former strategy corresponds to an evolutionary increase in growth rate, whereas the latter corresponds to an increase in the maximum amount of organisms or carrying capacity. What determines the strategies to be adopted during evolution? Spatial structures that compartmentalize the population into small patches are key to inducing the K‐strategy. Interestingly, previous evolution experiments usingEscherichia coliin a glucose‐limited batch culture showed that carrying capacity could improve evolutionally even in the absence of spatial structures. However, it is unclear if the lack of spatial structures can direct evolution toward high carrying capacity for utilization of other resources. To address this question, we established a simplified evolution experiment using histidine‐requiringE. coligrown under histidine limitation in a container with compartments. We confirmed the importance of spatial structures in K‐strategy evolution in histidine utilization. Whole genome sequencing of the K‐adapted strains showed functional variety of the mutated genes during the fitness‐increasing period. These results validate the importance of spatial structures and imply that restriction of K‐strategy evolution on a sort of nutrients is attributable to a paucity of appropriate selection rather than a paucity of causal mutation.