Replication factor C1 (RFC1) is required for double-strand break repair during meiotic homologous recombination in Arabidopsis
Replication factor C1 (RFC1) is required for double-strand break repair during meiotic homologous recombination in Arabidopsis
复制标题
拟南芥减数分裂同源重组期间的双链断裂修复需要复制因子 C1 (RFC1)
DOI：
10.1111/tpj.12024
复制
发表时间：
2013-01-01
期刊：
影响因子：
7.2
通讯作者：
Zhao, Jie
中科院分区：
文献类型：
--
作者：
Liu, Yang;Deng, Yingtian;Zhao, Jie
复制因子 C1 (RFC1) 在真核生物中保守，参与 DNA 复制和检查点控制。然而，拟南芥中尚未有 RFC1 产物参与减数分裂时 DNA 修复的报道。在这里，我们通过分析 rfc1-2 突变体报告了 AtRFC1 的功能特征。 rfc1-2突变体表现出正常的营养生长，但表现出长角果不育性，因为雄性配子体在单核小孢子阶段被抑制，而雌性配子体在功能性大孢子阶段被抑制。 AtRFC1的表达集中在生殖器官原基、性母细胞和发育中的配子中。染色体扩散显示配对和突触正常，在前期I晚期去突触开始时染色体断裂，而染色体片段保留在后续阶段。因此，同源染色体和姐妹染色单体分离不均等，导致花粉不育。免疫定位显示，在野生型的合子期和粗线期，AtRFC1 蛋白定位于染色体，但在 spo11-1 突变体中不存在。 rfc1-2 的染色体断裂被 spo11-1 抑制，表明 AtRFC1 作用于 AtSPO11-1 的下游。 rad51 rfc1-2 和 rad51 的相似染色体行为表明 AtRFC1 可能与 AtRAD51 在同一途径中发挥作用。总之，AtRFC1是拟南芥减数分裂同源重组过程中DNA双链断裂修复所必需的。
Replication factor C1 (RFC1), which is conserved in eukaryotes, is involved in DNA replication and checkpoint control. However, a RFC1 product participating in DNA repair at meiosis has not been reported in Arabidopsis. Here, we report functional characterization of AtRFC1 through analysis of the rfc1-2 mutant. The rfc1-2 mutant displayed normal vegetative growth but showed silique sterility because the male gametophyte was arrested at the uninucleus microspore stage and the female at the functional megaspore stage. Expression of AtRFC1 was concentrated in the reproductive organ primordia, meiocytes and developing gametes. Chromosome spreads showed that pairing and synapsis were normal, and the chromosomes were broken when desynapsis began at late prophase I, and chromosome fragments remained in the subsequent stages. For this reason, homologous chromosomes and sister chromatids segregated unequally, leading to pollen sterility. Immunolocalization revealed that the AtRFC1 protein localized to the chromosomes during zygotene and pachytene in wild-type but were absent in the spo11-1 mutant. The chromosome fragmentation of rfc1-2 was suppressed by spo11-1, indicating that AtRFC1 acted downstream of AtSPO11-1. The similar chromosome behavior of rad51 rfc1-2 and rad51 suggests that AtRFC1 may act with AtRAD51 in the same pathway. In summary, AtRFC1 is required for DNA double-strand break repair during meiotic homologous recombination of Arabidopsis.