What is the origin of mutations? In contrast to the naïve notion that mutations are unfortunate accidents, genetic research in microorganisms has demonstrated that most mutations are created by genetically-encoded error-prone repair mechanisms. However, error-free repair pathways also exist, and it is still unclear how cells decide when to use one repair method or the other. Here we summarize what is known about the DNA damage tolerance (DDT) mechanisms (also known as post-replication repair or PRR) for perhaps the best studied organism, the yeast Saccharomyces cerevisiae. We describe the latest research, which has established the existence of at least two error-free and two error-prone inter-related mechanisms of damage tolerance that compete for the handling of spontaneous DNA damage. We explore what is known about the induction of mutations by DNA damage. We point to potential paradoxes and to open questions that still remain unanswered.

中文翻译：

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DNA 损伤旁路途径及其对酵母诱变的影响。

突变的起源是什么？与认为突变是不幸事故的幼稚观念相反，微生物的遗传研究表明，大多数突变是由基因编码的易错修复机制产生的。然而，也存在无错误的修复途径，目前尚不清楚细胞如何决定何时使用一种修复方法或另一种修复方法。在这里，我们总结了关于 DNA 损伤耐受 (DDT) 机制（也称为复制后修复或 PRR）的已知信息，可能是研究得最好的生物体——酿酒酵母。我们描述了最新的研究，该研究已经确定存在至少两个无错误和两个容易出错的相关损伤耐受机制，它们竞争处理自发性 DNA 损伤。我们探索了关于 DNA 损伤诱导突变的已知信息。我们指出潜在的悖论并提出仍然没有答案的问题。