Am Nat. 2024 Oct;204(4):370-380. doi: 10.1086/731996. Epub 2024 Sep 4.
AbstractHost organisms can harbor microbial symbionts that defend them from pathogen infection in addition to the resistance encoded by the host genome. Here, we investigated how variation in defenses, generated from host genetic background and symbiont presence, affects the emergence of pathogen genetic diversity across evolutionary time. We passaged the opportunistic pathogen through populations of the nematode varying in genetic-based defenses and prevalence of a protective symbiont. After 14 passages, we assessed the amount of genetic variation accumulated in evolved pathogen lineages. We found that diversity begets diversity. An overall greater level of pathogen whole-genome and per-gene genetic diversity was measured in pathogens evolved in mixed host populations compared with those evolved in host populations composed of one type of defense. Our findings directly demonstrate that symbiont-generated heterogeneity in host defense can be a significant contributor to pathogen genetic variation.
摘要
除了宿主基因组编码的抗性之外，宿主生物还可以容纳防御病原体感染的微生物共生体。在这里，我们研究了防御机制的变异，这种变异来自宿主遗传背景和共生体的存在，它如何影响病原体遗传多样性在进化时间上的出现。我们通过在遗传防御和保护共生体流行率上存在差异的线虫种群来传代机会性病原体。经过 14 次传代后，我们评估了进化病原体谱系中积累的遗传变异量。我们发现多样性产生多样性。与在由一种防御类型组成的宿主种群中进化的病原体相比，在混合宿主种群中进化的病原体具有更高水平的整体全基因组和每个基因的遗传多样性。我们的发现直接表明，宿主防御中由共生体产生的异质性可以成为病原体遗传变异的重要贡献者。
