Studying DNA double-strand break repair: An ever-growing toolbox

To ward off against the catastrophic consequences of persistent DNA double-strand breaks (DSBs), eukaryotic cells have developed a set of complex signaling networks that detect these DNA lesions, orchestrate cell cycle checkpoints and ultimately lead to their repair. Collectively, these signaling networks comprise the DNA damage response (DDR). The current knowledge of the molecular determinants and mechanistic details of the DDR owes greatly to the continuous development of ground-breaking experimental tools that couple the controlled induction of DSBs at distinct genomic positions with assays and reporters to investigate DNA repair pathways, their impact on other DNA-templated processes and the specific contribution of the chromatin environment. In this review, we present these tools, discuss their pros and cons and illustrate their contribution to our current understanding of the DDR.Work in the SA lab was funded by PTDC/BIM-ONC/0016/2014 and PTDC/BIA-MOL/30438/2017 from Fundação para a Ciência e a Tecnologia (FCT), Portugal; by LISBOA-01-0145-FEDER-007391, project co-funded by FEDER through POR Lisboa, Portugal 2020–Programa Operacional Regional de Lisboa, and FCT; and by the IMM-Laço Fund. The GL laboratory was funded by grants from the European Research Council (ERC-2014-CoG 647344), Agence Nationale pour la Recherche (ANR-18-CE12-0015-02), the Institut National contre le Cancer (INCA), and the Ligue Nationale contre le Cancer (LNCC).Peer reviewe