PDF(Pubmed)
Abstract：
Many nonsporulating bacterial species survive prolonged resource exhaustion, by entering a state termed long-term stationary phase. Here, we performed long-term stationary phase evolutionary experiments on the bacterium Pseudomonas putida, followed by whole-genome sequencing of evolved clones. We show that P. putida is able to persist and adapt genetically under long-term stationary phase. We observed an accumulation of mutations within the evolving P. putida populations. Within each population, independently evolving lineages are established early on and persist throughout the 4-month-long experiment. Mutations accumulate in a highly convergent manner, with similar loci being mutated across independently evolving populations. Across populations, mutators emerge, that due to mutations within mismatch repair genes developed a much higher rate of mutation than other clones with which they coexisted within their respective populations. While these general dynamics of the adaptive process are quite similar to those we previously observed in the model bacterium Escherichia coli, the specific loci that are involved in adaptation only partially overlap between P. putida and E. coli.
摘要：
许多非孢子细菌物种在长时间的资源枯竭中存活，通过进入称为长期稳定阶段(LTSP)的状态。这里,我们对恶臭假单胞菌进行了LTSP进化实验，然后是进化克隆的全基因组测序。我们表明，P.putida能够在LTSP下持续存在并适应基因。我们观察到不断发展的恶臭假单胞菌种群中突变的积累。在每个人口中，独立进化的谱系在早期建立，并在整个四个月的实验中持续存在。突变以高度趋同的方式积累，相似的基因座在独立进化的种群中发生突变。在人群中，变种出现，由于错配修复基因中的突变，其突变率比与它们共存于各自种群中的其他克隆高得多。虽然适应过程的这些一般动力学与我们以前在模型细菌大肠杆菌中观察到的非常相似，参与适应的特定基因座仅在恶臭假单胞菌和大肠杆菌之间部分重叠。
