Programmed induction of DNA double strand breaks during meiosis: setting up communication between DNA and the chromosome structure.

During the first meiotic prophase, hundreds of DNA double strand breaks (DSBs) are deliberately self-inflicted along chromosomes in order to promote homologous recombination between homologs. These DSBs, catalyzed by the evolutionary conserved Spo11 protein, are highly regulated. Recent studies in yeast and mammals have identified key components involved in meiotic DSB formation. In mammals, the DNA binding specificity of PRDM9 determines where DSB occur, whereas in yeast, Spo11 acts in regions which one important feature is chromatin accessibility. However, DSB formation requires additional proteins located on chromosome axes, and the Saccharomyces cerevisiae protein, Spp1 has been recently identified to make the link between axes and DSB sites. These recent findings open exciting routes to understanding how the requirement to regulate DSBs along and between homologs is achieved.