Competence-mediated DNA uptake diversifies Vibrio cholerae sedentary chromosomal integrons
Summary
Bacteria often survive viral attack and environmental stress by sharing genes that enhance their defenses. The cholera pathogen Vibrio cholerae carries a sedentary chromosomal integron (SCI), a genetic element containing hundreds of mostly promoterless gene cassettes, about 10% of which encode antiviral systems. Cassettes are thought to reshuffle under stress to the favorable first array position, yet the SCI in pandemic V. cholerae has remained static for more than 60 years. In this study
Content
# Competence-mediated DNA uptake diversifies Vibrio cholerae sedentary chromosomal integrons
*Published: 2026 Apr 9*
Bacteria often survive viral attack and environmental stress by sharing genes
that enhance their defenses. The cholera pathogen Vibrio cholerae carries a
sedentary chromosomal integron (SCI), a genetic element containing hundreds of
mostly promoterless gene cassettes, about 10% of which encode antiviral systems.
Cassettes are thought to reshuffle under stress to the favorable first array
position, yet the SCI in pandemic V. cholerae has remained static for more than
60 years. In this study, we show that SCI diversification efficiently occurs by
horizontal transfer linked to the genus's aquatic lifestyle: DNA released from
lysed cells is taken up by naturally competent vibrios and integrated into the
first position of the SCI array, the primary site of strong expression, where it
confers resistance to phage and potentially other threats.
DOI: 10.1126/science.aed0645