Identification of adaptive changes in an evolving population of Escherichia coli: the role of changes with regulatory and highly pleiotropic effects.
Identification of adaptive changes in an evolving population of Escherichia coli: the role of changes with regulatory and highly pleiotropic effects.
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DOI：
10.1093/oxfordjournals.molbev.a040650
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发表时间：
1991-05
影响因子：
10.7
通讯作者：
Anna Kurlandzka;R. Rosenzweig;Julian Adams
中科院分区：
文献类型：
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作者：
Anna Kurlandzka;R. Rosenzweig;Julian Adams
从单个克隆开始的大肠杆菌种群在葡萄糖限制的连续培养中保持了773代后，表现出广泛的形态和生理多态。为了了解适应环境的机制，用双向凝胶电泳法检测了4个适应克隆和亲本菌株的总蛋白质图谱。在亲本克隆和适应克隆的配对比较中，大约20%的蛋白质(绝对数约为160)显示出显著不同的表达水平。这些变化的程度表明了在适应过程中具有调节和/或高度多效性效应的突变的重要性。四个进化克隆都比亲本菌株表达更少的蛋白质，支持进化过程中能量守恒的假说。鉴定出了42种可能属于已知细胞功能的蛋白质。其中一些无性系的变化表明，进化的无性系对葡萄糖限制的环境具有不同的适应机制。观察到与翻译、膜成分、休克反应和主动转运相关的蛋白质表达水平的变化。考虑到克隆人进化所处环境的性质，其中的一小部分变化既不能解释，也不能预测。
A population of Escherichia coli initiated with a single clone developed extensive morphological and physiological polymorphism after being maintained for 773 generations in glucose-limited continuous culture. To understand the mechanisms of adaptation to this environment, total protein patterns of four adaptive clones and of the parent strains were examined by two-dimensional gel electrophoresis. Approximately 20% of the proteins (approximately 160 in absolute numbers) showed significantly different levels of expression in pairwise comparisons of parent and adapted clones. The extent of these changes points to the importance of mutations with regulatory and/or highly pleiotropic effects in the adaptive process. The four evolved clones all expressed fewer proteins than did the parent strain, supporting the hypothesis of energy conservation during evolutionary change. Forty-two proteins that could be assigned to known cellular functions were identified. The changes in some of them indicated that the evolved clones developed different adaptive mechanisms to glucose-limited environment. Changes were observed in the expression levels of proteins associated with translation, membrane composition, shock response, and active transport. A fraction of the changes could not be either explained or predicted from a consideration of the nature of the environment in which the clones evolved.