ATAXIA TELANGIECTASIA-MUTATED (ATM) protein has been well studied for its roles in the DNA damage response. However, its role in meiosis has not been fully explored. Here, we characterized the functions of the rice (Oryza sativa) ATM homolog during meiosis. Aberrant chromosome associations and DNA fragmentations were observed after the completion of homologous pairing and synapsis in Osatm pollen mother cells (PMCs). Aberrant chromosome associations disappeared in Osspo11-1 Osatm-1 double mutants and more severe defects were observed in Osdmc1 Osatm, suggesting that OsATM functions downstream of OsSPO11-1-catalyzed double-strand break formation and in parallel with OsDMC1-mediated homologous recombination. We further demonstrated that phosphorylation of H2AX in PMCs did not depend on OsATM, in contrast to the situation in somatic cells. Moreover, the removal of OsDMC1 from chromosomes in Osatm PMCs was delayed and the number of HEI10 foci (markers of interference-sensitive crossover intermediates) decreased. Together, these findings suggest that OsATM plays important roles in the accurate repair of meiotic double-strand breaks in rice.

已经对ATAXIA TELANGIECTASIA-MUTATED（ATM）蛋白在DNA损伤反应中的作用进行了深入研究。但是，其在减数分裂中的作用尚未得到充分研究。在这里，我们表征了水稻（Oryza sativa）ATM同源物在减数分裂过程中的功能。在Osatm花粉母细胞（PMC）中完成同源配对和突触后，观察到异常的染色体关联和DNA片段化。异常染色体协会消失Osspo11-1 Osatm-1双突变体和更严重的缺陷中观察到Osdmc1 Osatm，表明OsATM在OsSPO11-1催化的双链断裂形成的下游起作用，并与OsDMC1介导的同源重组平行。我们进一步证明，与体细胞中的情况相比，PMC中H2AX的磷酸化不依赖于OsATM。此外，延迟了从Osatm PMC的染色体中去除OsDMC1，减少了HEI10病灶（干扰敏感交叉中间体的标记）的数量。总之，这些发现表明，OsATM在水稻减数分裂双链断裂的准确修复中起着重要作用。