Selection-Driven Gene Inactivation in Salmonella
Selection-Driven Gene Inactivation in Salmonella
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DOI：
10.1093/gbe/evaa010
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发表时间：
2020-03-01
影响因子：
3.3
通讯作者：
Cherry, Joshua L.
中科院分区：
文献类型：
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作者：
Cherry, Joshua L.
有时发现细菌基因因突变而失活。这种失活可能是可观察到的，仅仅是因为功能选择是间歇性的或太弱而不能快速消除失活等位基因。在这里，我调查的情况下，沙门氏菌肠道灭活，而不是积极选择。这些通过将提前终止密码子引入基因的速率来鉴定，该速率高于选择性中性下的预期，如通过与同义变化的速率进行比较来评估的。我确定了84个基因，符合这一标准，在10%的错误发现率。这些基因中的许多涉及毒力、运动性和趋化性、生物膜形成以及对抗生素或其他有毒物质的抗性。据推测，这些基因中的大多数受到一个持续的过程，其中失活是有利的在罕见的条件下，但失活的等位基因是有害的在大多数其他条件下，随后被驱动到灭绝的纯化选择。
Bacterial genes are sometimes found to be inactivated by mutation. This inactivation may be observable simply because selection for function is intermittent or too weak to eliminate inactive alleles quickly. Here, I investigate cases in Salmonella enterica where inactivation is instead positively selected. These are identified by a rate of introduction of premature stop codons to a gene that is higher than expected under selective neutrality, as assessed by comparison to the rate of synonymous changes. I identify 84 genes that meet this criterion at a 10% false discovery rate. Many of these genes are involved in virulence, motility and chemotaxis, biofilm formation, and resistance to antibiotics or other toxic substances. It is hypothesized that most of these genes are subject to an ongoing process in which inactivation is favored under rare conditions, but the inactivated allele is deleterious under most other conditions and is subsequently driven to extinction by purifying selection.