MRE11 is required for homologous synapsis and DSB processing in rice meiosis
MRE11 is required for homologous synapsis and DSB processing in rice meiosis
复制标题
MRE11 是水稻减数分裂中同源突触和 DSB 处理所必需的。
DOI：
10.1007/s00412-013-0421-1
复制
发表时间：
2013-10-01
期刊：
影响因子：
1.6
通讯作者：
Cheng, Zhukuan
中科院分区：
文献类型：
--
作者：
Ji, Jianhui;Tang, Ding;Cheng, Zhukuan
Mre 11是一种在从酵母到多细胞生物的生物体中发现的保守蛋白，是正常减数分裂重组所必需的。Mre 11与Rad 50和Nbs 1/Xrs 2相互作用形成复合物（MRN/X），该复合物参与双链断裂（DSB）末端加工。在本研究中，我们沉默了水稻中的MRE 11基因，并通过分子和细胞学方法详细研究了其功能。OsMRE 11缺陷植物表现出正常的营养生长，但不能结籽。细胞学分析表明，OsMRE 11基因缺失的植株在中期I时，同源配对完全被抑制，染色体完全缠结形成多价体，导致后期I时染色体严重断裂。免疫荧光研究进一步证明OsMRE 11是同源突触和DSB加工所必需的，但对于减数分裂DSB的形成是不必要的。我们发现OsMRE 11蛋白定位于减数分裂间期至粗线期晚期的染色体上。该蛋白在zep 1、Oscom 1和Osmer 3以及OsSPO 11 -1（RNAi）植物中显示正常定位，但在pair 2和pair 3突变体中不显示。综上所述，我们的研究结果提供了证据，OsMRE 11执行的功能，维持正常的HR过程中，抑制减数分裂过程中的非同源重组至关重要。
Mre11, a conserved protein found in organisms ranging from yeast to multicellular organisms, is required for normal meiotic recombination. Mre11 interacts with Rad50 and Nbs1/Xrs2 to form a complex (MRN/X) that participates in double-strand break (DSB) ends processing. In this study, we silenced the MRE11 gene in rice and detailed its function using molecular and cytological methods. The OsMRE11-deficient plants exhibited normal vegetative growth but could not set seed. Cytological analysis indicated that in the OsMRE11-deficient plants, homologous pairing was totally inhibited, and the chromosomes were completely entangled as a formation of multivalents at metaphase I, leading to the consequence of serious chromosome fragmentation during anaphase I. Immunofluorescence studies further demonstrated that OsMRE11 is required for homologous synapsis and DSB processing but is dispensable for meiotic DSB formation. We found that OsMRE11 protein was located on meiotic chromosomes from interphase to late pachytene. This protein showed normal localization in zep1, Oscom1 and Osmer3, as well as in OsSPO11-1 (RNAi) plants, but not in pair2 and pair3 mutants. Taken together, our results provide evidence that OsMRE11 performs a function essential for maintaining the normal HR process and inhibiting non-homologous recombination during meiosis.