| First Author | Blanco-Rodríguez J | Year | 2012 |
| Journal | Reproduction | Volume | 144 |
| Issue | 6 | Pages | 699-712 |
| PubMed ID | 23035256 | Mgi Jnum | J:195900 |
| Mgi Id | MGI:5486116 | Doi | 10.1530/REP-12-0326 |
| Citation | Blanco-Rodriguez J (2012) Programmed phosphorylation of histone H2AX precedes a phase of DNA double-strand break-independent synapsis in mouse meiosis. Reproduction 144(6):699-712 |
| abstractText | Accurate homologue synapsis during meiosis is essential for faithful chromosome segregation and formation of viable gametes. The finding of Spo11-dependent gamma-H2AX (gammaH2AX) formation during leptotene and data on mutant mice have led to the notion that synapsis in mammals depends on meiotic DNA double-stranded break (DSB) repair. A second wave of ataxia telangiectasia mutated (ATM) and Rad3-related (ATR)-dependent gammaH2AX formation has been observed in Atm-null mice during zygotene, suggesting that this wave of phosphorylation also occurs in normal mice. Here I aimed to confirm and to analyse in deep this wave of phosphorylation. Immunostaining of spread spermatocytes shows that gammaH2AX accumulates on the short last axis stretches to pair. This accumulation appears within all the nuclei undergoing a specific step of late zygotene and disappears from every spermatocyte immediately after pairing completion. This gammaH2AX signal co-localises with ATR, is Spo11-independent and does not co-localise with free DNA 3'-end labelling. I conclude that ATR/gammaH2AX asynapsis signalling at the end of zygotene belongs to a physiologically programmed pathway operating at a specific meiotic step, and I propose that this pathway is involved in the triggering of a phase of DSB-independent chromosome pairing that leads to synapsis completion in normal mouse meiosis. |
