Belt and braces: Two escape ways to maintain the cassette reservoir of large chromosomal integrons.

ABSTRACT: Integrons are adaptive devices that capture, stockpile, shuffle and express gene cassettes thereby sampling combinatorial phenotypic diversity. Some integrons called sedentary chromosomal integrons (SCIs) can be massive structures containing hundreds of cassettes. Since most of these cassettes are non-expressed, it is not clear how they remain stable over long evolutionary timescales. Recently, it was found that the experimental inversion of the SCI of Vibrio cholerae led to a dramatic increase of the cassette excision rate associated with a fitness defect. Here, we question the evolutionary sustainability of this apparently counter selected genetic context. Through experimental evolution, we find that the integrase is rapidly inactivated and that the inverted SCI can recover its original

SUBMITTER: Richard E 

PROVIDER: S-EPMC11023631 | biostudies-literature | 2024 Apr

REPOSITORIES: biostudies-literature