Overview
- A UCLA-led study in Science catalogs more than 1,100 distinct diversity-generating retroelements across Bacteroides, averaging roughly one per strain with some carrying up to five.
- Roughly one-quarter of these elements target adhesion-related genes, diversifying tip adhesins on type V pili that mediate attachment and colonization.
- The elements can move between bacterial strains via horizontal transfer, spreading adaptive potential within gut communities.
- Analyses of mother–infant pairs show specific elements are passed to infants and generate new variants in Bacteroides pili during early-life colonization.
- In vitro assays and gnotobiotic mouse experiments indicate DGR-driven variants are produced randomly in isolation but converge under competition, consistent with positive selection.