Bacterial lifestyle shapes pangenomes

• 成果类型: Article
• 署名作者: Dewar, Anna E.; Hao, Chunhui; Belcher, Laurence J.; Ghoul, Melanie; West, Stuart A.
• 署名单位: University of Oxford
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9545
• DOI: 10.1073/pnas.2320170121
• 发表日期: 2024-05-21
• 关键词: population-genetics; EVOLUTION; ecology

摘要

Pangenomes vary across bacteria. Some species have fluid pangenomes, with a high pangenomes, with different genomes tending to contain the same genes. Two main hypotheses have been suggested to explain this variation: differences in species' bacterial lifestyle and effective population size. However, previous studies have not been able to test between these hypotheses because the different features of lifestyle and effective population size are highly correlated with each other, and phylogenetically conserved, making it hard to disentangle their relative importance. We used phylogeny- based analyses, across 126 bacterial species, to tease apart the causal role of different factors. We found that pangenome fluidity was lower in i) host- associated compared with free- living species and ii) host- associated species that are obligately dependent on a host, live inside cells, and are more pathogenic and less motile. In contrast, we found no support for the competing hypothesis that larger effective population sizes lead to more fluid pangenomes. Effective population size appears to correlate with pangenome variation because it is also driven by bacterial lifestyle, rather than because of a causal relationship.