Introgression impacts the evolution of bacteria, but species borders are rarely fuzzy.

ABSTRACT: Most bacteria engage in gene flow through homologous recombination, and this mechanism may play a crucial role in maintaining species cohesiveness, much like sexual reproduction does in eukaryotes. However, introgression has been reported in bacteria and is associated with fuzzy species borders in some lineages, but its prevalence and impact on the delimitation of bacterial species have not been systematically characterized. Here, we use the term "introgression" to describe gene flow between the genomic backbone of distinct species (i.e., their core genomes)-an analogy to the classical usage in sexual organisms, but distinct in mechanism. We quantified the patterns of introgression across 50 major bacterial lineages. Our results reveal that bacteria present various levels of introgression,

SUBMITTER: Diop A 

PROVIDER: S-EPMC12615716 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature