Evolution of the genetic switch in temperate bacteriophage .1. Basic theory
Evolution of the genetic switch in temperate bacteriophage .1. Basic theory
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DOI：
10.1006/jtbi.1996.0056
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发表时间：
1996-03-21
影响因子：
2
通讯作者：
Mittler, JE
中科院分区：
文献类型：
--
作者：
Mittler, JE
虽然噬菌体的溶原性和诱导的分子机制已经得到了深入的研究，但相对较少的研究将这些发现与它们假定的选择性功能联系起来。为了探索这些特征的生态学基础，我使用了一个基于资源的模型，用于具有不同溶原性概率和不同自发诱导率的噬菌体之间的竞争。在任何给定的栖息地中，噬菌体的适应性将取决于敏感细胞和营养资源的输入。在稳定的环境中（这里使用恒化器模拟，不断输入营养物质和敏感细胞），溶源性和诱导率低的噬菌体总是可以在罕见时入侵，通常是很好的竞争对手。在可变的环境中（具有季节性输入的恒化器），具有较高溶原性概率和较高诱导率的噬菌体是有利的。在均匀和可变的环境中，噬菌体在稀有时的入侵能力将取决于常驻噬菌体的特性，并且具有不同参数值的噬菌体有可能共存。模型表明，已经进化出中等低诱导率和溶原率的噬菌体将能够“对冲”环境变化，而不会牺牲在恒定环境中良好竞争的能力。讨论了这一理论对理解温和噬菌体和其他病毒基因调控的分子基础的影响。(C)出版社：Academic Press Limited。
While the molecular mechanisms underlying lysogeny and induction in bacteriophage have been intensely studied, relatively little has been done to relate these findings to their presumed selective functions. To explore the ecological basis for these traits, I have used a resource-based model for competition between bacteriophage with different probabilities of lysogeny and different spontaneous induction rates. In any given habitat the fitness of a phage will depend on the inputs of sensitive cells and nutrient resources. In equable environments (modeled here using chemostats with constant inputs of nutrients and sensitive cells), bacteriophage with low probabilities of lysogeny and low induction rates can always invade when rare and will generally be good competitors. In variable environments (chemostats with seasonal inputs), bacteriophage with higher probabilities of lysogeny and higher induction rates are favored. In both equable and variable environments, the ability of a phage to invade when rare will depend on the properties of the resident phage, and it is possible for phages with divergent parameter values to coexist. The modeling suggests that bacteriophage that have evolved moderately low induction and lysogeny rates will be able to ''hedge their bets'' against environmental change without sacrificing the ability to compete well in a constant environment. Implications of this theory for understanding the molecular basis of gene regulation in temperate bacteriophage and other viruses are discussed. (C) 1996 Academic Press Limited.