Meaden Sean, Westra Edze R, Fineran Peter C
Department of Biology, University of York, York YO10 5DD, UK.
York Biomedical Research Institute, University of York, York YO10 5DD, UK.
Philos Trans R Soc Lond B Biol Sci. 2025 Sep 4;380(1934):20240069. doi: 10.1098/rstb.2024.0069.
The defence systems bacteria use to protect themselves from their viruses are mechanistically and genetically diverse. Yet the ecological conditions that predict when defences are selected for remain unclear, as substantial variation in defence prevalence has been reported. Experimental work in simple communities suggests ecological factors can determine when specific defence systems are most beneficial, but applying these findings to complex communities has been challenging. Here, we use a comprehensive and environmentally balanced collection of metagenomes to survey the defence landscape across complex microbial communities. We also assess the association between the viral community and the prevalence of defence systems. We identify strong environmental effects in predicting overall defence abundance, with animal-host-associated environments and hot environments harbouring more defences overall. We also find a positive correlation between the density and diversity of viruses in the community and the abundance of defence systems. This study provides insights into the ecological factors that influence the composition and distribution of bacterial defence systems in complex microbial environments and outlines future directions for the study of defence-system ecology.This article is part of the discussion meeting issue 'The ecology and evolution of bacterial immune systems'.
细菌用于保护自身免受病毒侵害的防御系统在机制和基因方面具有多样性。然而，预测何时会选择防御机制的生态条件仍不明确，因为已有报道称防御机制的流行存在很大差异。在简单群落中进行的实验工作表明，生态因素可以决定特定防御系统何时最为有益，但将这些发现应用于复杂群落一直具有挑战性。在这里，我们使用了一个全面且环境平衡的宏基因组集合，以调查复杂微生物群落中的防御格局。我们还评估了病毒群落与防御系统流行率之间的关联。我们发现在预测总体防御丰度方面存在强烈的环境影响，与动物宿主相关的环境和高温环境总体上拥有更多的防御机制。我们还发现群落中病毒的密度和多样性与防御系统的丰度之间存在正相关。这项研究深入探讨了影响复杂微生物环境中细菌防御系统组成和分布的生态因素，并概述了防御系统生态学研究的未来方向。本文是“细菌免疫系统的生态学与进化”讨论会议题的一部分。
