One of the two major pathways involved in double-strand breaks repair is homologous recombination. The HR pathway operates mostly in the S and G2 phases of the cell cycle. HR provides a mechanism to precisely repair damaged DNA lesions such as double-strand breaks (DSBs) which threaten the integrity of the genome. DSBs repaired by HR are first end-resected to generate 3’ single-stranded DNA (ssDNA). A DNA strand exchange protein – RAD51 in mammalian cells – binds to the ssDNA to form a nucleoprotein filament which promotes strand invasion into a homologous duplex to initiate repair synthesis. In the Synthesis-Dependent Strand Annealing (SDSA) pathway of HR, the newly synthesized DNA dissociates to anneal to the other DNA end and the HR event
