DNA Double‐strand Breaks and Their Consequences in Bacteria

Deoxyribonucleic acid (DNA) double-strand breaks, which are caused by many factors such as chemical treatments, radiations and, often, biological factors, are lethal events in organisms carrying DNA as their genome include bacteria. There are various mechanisms that work, sometimes in collaboration or competition with each other, in the processing of these breaks. These include exonucleolytic degradation, end joining and recombination repair. These may bring about death, restoration or recombinational/mutational changes in the genome. Intragenomic collaboration and conflict between various pathways can be a force in their genome evolution. Recent analyses suggest that DNA double-strand breaks switch on the programme of cell death in bacteria. DNA double-strand breakage and its consequences in bacteria may provide a good model system to analyse the dynamic relationship between life, death and evolution. Understanding these processes in bacteria is important in medicine, environmental studies and industrial application. Key concepts: DNA double-strand breakage and its consequences in bacteria may provide a model system to analyse the relationship between life, death and evolution. DNA double-strand breakage may switch on programmes of cell death in bacteria. Keywords: recombination; restriction enzyme; programmed cell death; DNA methylation; genome evolution