{"title":"Defence systems and horizontal gene transfer in bacteria","authors":"Roman Kogay, Yuri I. Wolf, Eugene V. Koonin","doi":"10.1111/1462-2920.16630","DOIUrl":null,"url":null,"abstract":"<p>Horizontal gene transfer (HGT) is a fundamental process in prokaryotic evolution, contributing significantly to diversification and adaptation. HGT is typically facilitated by mobile genetic elements (MGEs), such as conjugative plasmids and phages, which often impose fitness costs on their hosts. However, a considerable number of bacterial genes are involved in defence mechanisms that limit the propagation of MGEs, suggesting they may actively restrict HGT. In our study, we investigated whether defence systems limit HGT by examining the relationship between the HGT rate and the presence of 73 defence systems across 12 bacterial species. We discovered that only six defence systems, three of which were different CRISPR-Cas subtypes, were associated with a reduced gene gain rate at the species evolution scale. Hosts of these defence systems tend to have a smaller pangenome size and fewer phage-related genes compared to genomes without these systems. This suggests that these defence mechanisms inhibit HGT by limiting prophage integration. We hypothesize that the restriction of HGT by defence systems is species-specific and depends on various ecological and genetic factors, including the burden of MGEs and the fitness effect of HGT in bacterial populations.</p>","PeriodicalId":11898,"journal":{"name":"Environmental microbiology","volume":null,"pages":null},"PeriodicalIF":4.3000,"publicationDate":"2024-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/1462-2920.16630","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental microbiology","FirstCategoryId":"99","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/1462-2920.16630","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Horizontal gene transfer (HGT) is a fundamental process in prokaryotic evolution, contributing significantly to diversification and adaptation. HGT is typically facilitated by mobile genetic elements (MGEs), such as conjugative plasmids and phages, which often impose fitness costs on their hosts. However, a considerable number of bacterial genes are involved in defence mechanisms that limit the propagation of MGEs, suggesting they may actively restrict HGT. In our study, we investigated whether defence systems limit HGT by examining the relationship between the HGT rate and the presence of 73 defence systems across 12 bacterial species. We discovered that only six defence systems, three of which were different CRISPR-Cas subtypes, were associated with a reduced gene gain rate at the species evolution scale. Hosts of these defence systems tend to have a smaller pangenome size and fewer phage-related genes compared to genomes without these systems. This suggests that these defence mechanisms inhibit HGT by limiting prophage integration. We hypothesize that the restriction of HGT by defence systems is species-specific and depends on various ecological and genetic factors, including the burden of MGEs and the fitness effect of HGT in bacterial populations.
期刊介绍:
Environmental Microbiology provides a high profile vehicle for publication of the most innovative, original and rigorous research in the field. The scope of the Journal encompasses the diversity of current research on microbial processes in the environment, microbial communities, interactions and evolution and includes, but is not limited to, the following:
the structure, activities and communal behaviour of microbial communities
microbial community genetics and evolutionary processes
microbial symbioses, microbial interactions and interactions with plants, animals and abiotic factors
microbes in the tree of life, microbial diversification and evolution
population biology and clonal structure
microbial metabolic and structural diversity
microbial physiology, growth and survival
microbes and surfaces, adhesion and biofouling
responses to environmental signals and stress factors
modelling and theory development
pollution microbiology
extremophiles and life in extreme and unusual little-explored habitats
element cycles and biogeochemical processes, primary and secondary production
microbes in a changing world, microbially-influenced global changes
evolution and diversity of archaeal and bacterial viruses
new technological developments in microbial ecology and evolution, in particular for the study of activities of microbial communities, non-culturable microorganisms and emerging pathogens