中文摘要：有人认为彻底消灭一种有毒病原体是拯救一个种群的最有效方法。而Skanata和Kussell研究则表明，对于细菌-噬菌体系统来说，维持最低病原体水平实际上有利于防止免疫力的完全丧失。
    细菌对噬菌体的防御，包括CRISPR介导的免疫和其他机制，可能会带来巨大的增长率成本，并可能在病原体被消灭时迅速丧失。面对不同的病原体水平和菌株间的竞争，细菌如何不计代价保持其分子防御，仍然是进化生物学中一个未解的主要问题。本研究提出了一个多层次的模型，该模型结合了分子结合的生物物理学、宿主-病原体种群动力学以及跨大量独立区域的生态动力学。利用博弈论和非线性动力系统的技术证明，通过保持防御的非零失败率，宿主在生态中维持足够水平的病原体以避免免疫力的丧失。这种抗性转换策略在进化上是稳定的，它提供了一种强大的进化机制，可以维持宿主-病原体的相互作用，选择能够避免免疫成本的欺骗菌株，并在广泛的系统中实现协同进化动力学。
外文摘要：One might think that complete extinction of a virulent pathogen is the most effective way of saving a population. For a bacteria-phage system, Skanata and Kussell show that sustaining a minimum pathogen level is actually favorable to prevent a complete loss of immunity in the long run.
   Bacterial defenses against phage, which include CRISPR-mediated immunity and other mechanisms, can carry substantial growth rate costs and can be rapidly lost when pathogens are eliminated. How bacteria preserve their molecular defenses despite their costs, in the face of variable pathogen levels and inter-strain competition, remains a major unsolved problem in evolutionary biology. Here, we present a multilevel model that incorporates biophysics of molecular binding, host-pathogen population dynamics, and ecological dynamics across a large number of independent territories. Using techniques of game theory and non-linear dynamical systems, we show that by maintaining a non-zero failure rate of defenses, hosts sustain sufficient levels of pathogen within an ecology to select against loss of the defense. This resistance switching strategy is evolutionarily stable, and provides a powerful evolutionary mechanism that maintains host-pathogen interactions, selects against cheater strains that avoid the costs of immunity, and enables co-evolutionary dynamics in a wide range of systems.
外文关键词：ESCHERICHIA-COLI；EVOLUTION；VIRUSES；DEFENSE；BIODIVERSITY；POLYMORPHISM；COEVOLUTION；MAINTENANCE；INHIBITION；DIVERSITY
作者：Skanata, A；Kussell, E
作者单位：NYU
期刊名称：NATURE COMMUNICATIONS
期刊影响因子：12.121
出版年份：2021
出版刊次：1
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