DNA Double Strand Break Repair in E. coli Perturbs Cell Division and Chromosome Dynamics

The effect of a site-specific DNA double-strand break on the abundance of E. coli chromosomal DNA during exponential growth was investigated by marker frequency analysis (MFA). Genomic DNA from 3 independent biological repeats of 4 strains (DL1777, DL2151, DL2859 and DL2874) was sequenced by whole genome sequencing. The genomic DNA from strain DL1777 was isolated from cultures at both stationary and exponential growth phases, whereas the other genomic DNA of the other three strains were isolated from cultures at exponential growth phase only. Strain DL2859 experiences the site-specific DSB, whereas strains DL1777, DL2151, and DL2874 do not. Genomic DNA from stationary phase cultures of strain DL1777 was used to control for differences in read number caused by genomic composition (rather than chromosome metabolism).