Moore Lindsay S, Wei Wu, Stolovicki Elad, Benbenishty Tamar, Wilkening Stefan, Steinmetz Lars M, Braun Erez, David Lior
Department of Physics & Network Biology Research Laboratories, Technion-Israel Institute of Technology, Haifa, Israel.
Stanford Genome Technology Center, Palo Alto, California, United States of America.
PLoS One. 2014 Oct 23;9(10):e111133. doi: 10.1371/journal.pone.0111133. eCollection 2014.
The modern evolutionary synthesis assumes that mutations occur at random, independently of the environment in which they confer an advantage. However, there are indications that cells facing challenging conditions can adapt rapidly, utilizing processes beyond selection of pre-existing genetic variation. Here, we show that a strong regulatory challenge can induce mutations in many independent yeast cells, in the absence of general mutagenesis. Whole genome sequencing of cell lineages reveals a repertoire of independent mutations within a single lineage that arose only after the cells were exposed to the challenging environment, while other cells in the same lineage adapted without any mutation in their genomes. Thus, our experiments uncovered multiple alternative routes for heritable adaptation that were all induced in the same lineage during a short time period. Our results demonstrate the existence of adaptation mechanisms beyond random mutation, suggesting a tight connection between physiological and genetic processes.
现代进化综合理论假定，突变是随机发生的，与它们赋予优势的环境无关。然而，有迹象表明，面临挑战性条件的细胞可以通过利用现有遗传变异选择之外的过程迅速适应。在这里，我们表明，在没有普遍诱变的情况下，强烈的调控挑战可以在许多独立的酵母细胞中诱导突变。细胞谱系的全基因组测序揭示了单个谱系内一系列独立的突变，这些突变仅在细胞暴露于具有挑战性的环境后才出现，而同一谱系中的其他细胞在基因组中没有任何突变的情况下就适应了。因此，我们的实验揭示了多种可遗传适应的替代途径，这些途径在短时间内都在同一谱系中被诱导。我们的结果证明了除随机突变之外的适应机制的存在，这表明生理过程和遗传过程之间存在紧密联系。
