Several attempts have been made to identify the minimal set of genes that is required for life using computational approaches or studies of deletion mutants. These experiments resemble those already performed by nature; a few hundred million years ago an ancestor of Escherichia coli was domesticated by aphids, which resulted in the elimination of 70-75% of the original bacterial genome. Amazingly, the small genomes of these imprisoned bacteria are more stable than those of their free-living relatives. Minimal-gene-sets that have evolved naturally are largely species-specific, with the exception of a small set of core genes that are required for information processing. Comparative genomics of host-dependent bacteria have shown that minimal-gene-sets can persist in nature for tens of millions of years provided that the environment is rich in nutrients, that the host population size is large and that there is a strong host-level selection for bacterial gene functions.

中文翻译：

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宿主依赖性细菌中最小基因集的进化。

使用计算方法或缺失突变体的研究，已经进行了几次尝试来鉴定生命所需的最小基因集。这些实验类似于自然界已经进行的实验。几亿年前，一种蚜虫将大肠杆菌的祖先驯化，从而消除了原始细菌基因组的70-75％。令人惊讶的是，这些被囚禁细菌的小型基因组比其自由生活的亲戚更稳定。自然进化的最小基因集在很大程度上是特定于物种的，但信息处理所需的少数核心基因除外。