During sexual reproduction haploid gametes are generated out of diploid mother cells. This ploidy reduction is accomplished during meiosis and, in most species, relies on the occurrence of homologous recombination that is triggered by the induction of a large number of DNA double strand breaks (DSBs). The mechanism by which such DSBs are generated without provoking massive DNA breakdown in gamete mother cells is still poorly understood. However, the recent characterisation, in plants and in mammals, of a new component of the meiotic DSB forming machinery, defining a meiotic-specific TOPOVIB-Like protein family, has established a clear connection between the meiotic DSB activity and topoisomerases, enzymes that modify the DNA topology by introducing transient DSBs.
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