title: Homologous pairing preceding SPO11-mediated double-strand breaks in mice.
abstract: How homologous chromosomes (homologs) find their partner, pair, and recombine during meiosis constitutes the central phenomenon in eukaryotic genetics. It is widely believed that, in most organisms, SPO11-mediated DNA double-strand breaks (DSBs) introduced during prophase I precede and are required for efficient homolog pairing. We now show that, in the mouse, a significant level of homolog pairing precedes programmed DNA cleavage. Strikingly, this early chromosome pairing still requires SPO11 but is not dependent on its ability to make DSBs or homologous recombination proteins. Intriguingly, SUN1, a protein required for telomere attachment to the nuclear envelope and for post-DSB synapsis, is also required for early pre-DSB homolog pairing. Furthermore, pre-DSB pairing at telomeres persists upon entry into prophase I and is most likely important for initiation of synapsis. Our findings suggest that the DSB-triggered homology search may mainly serve to proofread and stabilize the pre-DSB pairing of homologous chromosomes.
authors: National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
authors: Kingsley A
authors: KA
authors: Boateng
authors: Marina A
authors: MA
authors: Bellani
authors: Ivan V
authors: IV
authors: Gregoretti
authors: Florencia
authors: F
authors: Pratto
authors: R Daniel
authors: RD
authors: Camerini-Otero
mesh_terms: D000818:Animals; D023902:Chromosome Pairing; D002875:Chromosomes / Q000378:metabolism; D053903:DNA Breaks, Double-Stranded; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D008540:Meiosis / Q000235:genetics; D049469:Meiotic Prophase I / Q000235:genetics; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D016615:Telomere / Q000378:metabolism; D000099257:Meiotic Recombination Protein SPO11
chemical_list: D004706:Endodeoxyribonucleases; D008869:Microtubule-Associated Proteins; D000099257:Meiotic Recombination Protein SPO11; C464932:SUN1 protein, mouse