Broken replication forks trigger heritable DNA breaks in the terminus of a circular chromosome.

ABSTRACT: It was recently reported that the recBC mutants of Escherichia coli, deficient for DNA double-strand break (DSB) repair, have a decreased copy number of their terminus region. We previously showed that this deficit resulted from DNA loss after post-replicative breakage of one of the two sister-chromosome termini at cell division. A viable cell and a dead cell devoid of terminus region were thus produced and, intriguingly, the reaction was transmitted to the following generations. Using genome marker frequency profiling and observation by microscopy of specific DNA loci within the terminus, we reveal here the origin of this phenomenon. We observed that terminus DNA loss was reduced in a recA mutant by the double-strand DNA degradation activity of RecBCD. The terminus-less cell produced at t

SUBMITTER: Sinha AK 

PROVIDER: S-EPMC5862497 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature