The book of Lambda does not tell us that naturally occurring lysogens of Escherichia coli are likely to be resistant as well as immune.
The book of Lambda does not tell us that naturally occurring lysogens of Escherichia coli are likely to be resistant as well as immune.
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Lambda的书没有告诉我们，大肠杆菌的天然发生的脂质物可能具有抵抗力和免疫力。
DOI：
10.1073/pnas.2212121120
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发表时间：
2023-03-14
影响因子：
11.1
通讯作者：
中科院分区：
文献类型：
--
作者：
在细菌自然种群中大量存在的温和噬菌体在细菌克隆之间的基因水平传递中起着重要作用。这些基因通常编码毒素和其他负责致病细菌毒性的特征。虽然我们对这些病毒的遗传学和分子生物学有很多了解，但我们对它们在自然细菌群落中的种群和进化生物学知之甚少。这个联合的理论和实验研究的结果预测和目前的证据相反，从实验室研究的预期温带溶原性和溶原性，因为我们发现，自然发生的溶原性很可能是耐药的（难治性），而不仅仅是免疫的噬菌体编码的由他们的原噬菌体。噬菌体在功能上和生态上最显著的区别是它们是纯裂解性的（毒性的）还是温和的。毒力蜱只能通过感染水平传播，最常见的是宿主死亡。温杆菌也可以水平传播，但在感染易感细菌后，它们的基因组可以作为前噬菌体并入宿主的基因组中，并在溶原性宿主的细胞分裂过程中垂直传播。根据我们从对温带噬菌体λ和其他温带噬菌体的研究中所知道的，在实验室培养中，溶原性细菌通过免疫被其原噬菌体编码的噬菌体保护而不被杀死;在感染溶原性细菌时，由其原噬菌体编码的游离温带噬菌体丢失。为什么溶原菌具有抵抗力，而不仅仅是对由其原噬菌体编码的噬菌体免疫，因为免疫力并不赋予对剧毒噬菌体的保护？为了解决这个问题，我们使用了一个数学模型，并在实验室培养中进行了实验与温和和有毒的突变体的噬菌体λ。我们的模型预测和实验证实，选择将有利于抗性和免疫溶原的进化，特别是如果环境中包括毒性噬菌体，共享相同的受体作为温带。为了探索这种预测的有效性和普遍性，我们检查了10溶原性大肠杆菌从自然种群。这10种噬菌体都能形成免疫溶原，但它们的原宿主对它们的原噬菌体编码的噬菌体有抗性。
The temperate bacteriophages that abound in natural populations of bacteria play a prominent role in the horizontal transmission of genes between clones of bacteria. These phages often code for toxins and other characters responsible for the virulence of pathogenic bacteria. While a great deal is known about these viruses’ genetics and molecular biology, we know relatively little about their population and evolutionary biology in natural communities of bacteria. The results of this jointly theoretical and experimental study predict and present evidence contrary to what was anticipated from laboratory studies of temperate phages and lysogeny, as we found that naturally occurring lysogens are likely to be resistant (refractory) and not only immune to the phage coded for by their prophage. The most significant difference between bacteriophages functionally and ecologically is whether they are purely lytic (virulent) or temperate. Virulent phages can only be transmitted horizontally by infection, most commonly with the death of their hosts. Temperate phages can also be transmitted horizontally, but upon infection of susceptible bacteria, their genomes can be incorporated into that of their host’s as a prophage and be transmitted vertically in the course of cell division by their lysogenic hosts. From what we know from studies with the temperate phage Lambda and other temperate phages, in laboratory culture, lysogenic bacteria are protected from killing by the phage coded for by their prophage by immunity; where upon infecting lysogens, the free temperate phage coded by their prophage is lost. Why are lysogens resistant and not only immune to the phage coded by their prophage since immunity does not confer protection against virulent phages? To address this question, we used a mathematical model and performed experiments with temperate and virulent mutants of the phage Lambda in laboratory culture. Our models predict and experiments confirm that selection would favor the evolution of resistant and immune lysogens, particularly if the environment includes virulent phage that shares the same receptors as the temperate. To explore the validity and generality of this prediction, we examined 10 lysogenic Escherichia coli from natural populations. All 10 were capable of forming immune lysogens, but their original hosts were resistant to the phage coded by their prophage.
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影响因子：
2.9
作者：
STEWART, FM;LEVIN, BR
通讯作者：
LEVIN, BR
大肠杆菌K-12的构造框架，单基因敲除突变体：Keio Collection。
影响因子：
9.9
作者：
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--
影响因子：
3.3
作者：
KORONA, R;LEVIN, BR
通讯作者：
LEVIN, BR
影响因子：
9.8
作者：
Chaudhry, Waqas N.;Pleska, Maros;Levin, Bruce R.
通讯作者：
Levin, Bruce R.
影响因子：
5.4
作者：
BARNHART, BJ;COX, SH;JETT, JH
通讯作者：
JETT, JH