來自武漢大學(xué)生命科學(xué)學(xué)院,，雜交水稻國(guó)家重點(diǎn)實(shí)驗(yàn)室的研究人員發(fā)表了題為“Replication factor C1 (RFC1) is required for double-strandbreak repair during meiotic homologous recombination inArabidopsis”的文章,，發(fā)現(xiàn)了一種基因：AtRFC1能通過影響同源染色體和姐妹染色單體的均等分離，調(diào)控花粉遺傳物質(zhì)的分布,，為深入闡明減數(shù)分裂中同源重組的分子機(jī)制奠定了基礎(chǔ),。相關(guān)成果公布在植物學(xué)領(lǐng)域權(quán)威刊物The Plant Journal雜志上。
領(lǐng)導(dǎo)這一研究的是武大生科院趙潔教授,，趙教授早年畢業(yè)于華中師范大學(xué),，主要研究領(lǐng)域?yàn)橹参锷嘲l(fā)育生物學(xué)，以及植物性細(xì)胞操作與細(xì)胞工程,，目前科研項(xiàng)目包括“水稻花穗原基發(fā)生和生殖器官發(fā)育中AGP基因功能的研究”等。文章的第一作者是博士生劉揚(yáng)。
復(fù)制因子C包含1個(gè)大亞基和4個(gè)小亞基,，在DNA復(fù)制,、損傷修復(fù)和細(xì)胞增殖中起重要作用，其中擬南芥復(fù)制因子C亞基1(AtRFC1)是人類復(fù)制因子C大亞基p140的同源蛋白,，對(duì)這一基因的研究將有助于解析細(xì)胞的一些重要進(jìn)程,。
在這篇文章中，研究人員發(fā)現(xiàn)AtRFC1基因能通過影響花粉和胚囊發(fā)育控制擬南芥角果的育性,，并且也指出AtRFC1能通過影響同源染色體和姐妹染色單體的均等分離控制花粉遺傳物質(zhì)的分布,，從而參與花粉母細(xì)胞減數(shù)分裂的過程。
而且在減數(shù)分裂的同源重組中,，AtRFC1基因主要參與DNA雙鏈斷裂的修復(fù),，在AtSPO11-1基因的下游通路中發(fā)揮作用，此外這一基因還可能參與了AtRAD51介導(dǎo)的同源重組修復(fù),，從而揭示了AtRFC1基因參與植物DNA修復(fù)的機(jī)理,，這一研究為深入闡明減數(shù)分裂中同源重組的分子機(jī)制奠定了基礎(chǔ)。
另外近期這一研究組還發(fā)表了另外一項(xiàng)研究成果：發(fā)現(xiàn)擬南芥AtMT4a和AtMT4b基因的重要作用,，這對(duì)于揭示種子發(fā)育和萌發(fā)中ABA和GA激素,、MT基因與Zn離子供給及調(diào)控之間的關(guān)系具有重要的意義。
研究人員發(fā)現(xiàn)擬南芥AtMT4a和AtMT4b基因參與種子萌發(fā)及幼苗早期發(fā)育,，RNAi轉(zhuǎn)基因植株中種子重量減少,、幼苗早期生長(zhǎng)減緩，并且在胚胎晚期AtMT4a和AtMT4b特異表達(dá),。
研究人員也發(fā)現(xiàn)AtMT4a和AtMT4b蛋白主要通過與Zn金屬離子結(jié)合而調(diào)節(jié)細(xì)胞內(nèi)離子的貯存和分布,，維持金屬離子微環(huán)境的平衡，并且發(fā)現(xiàn) ABA和GA可能通過調(diào)節(jié)AtMT4a和AtMT4b的表達(dá)水平,、繼而通過鋅指轉(zhuǎn)錄因子和鋅結(jié)合蛋白的作用,，影響胚胎晚期和幼苗早期發(fā)育。這些研究對(duì)于揭示種子發(fā)育和萌發(fā)中ABA和GA激素,、MT基因與Zn離子供給及調(diào)控之間的關(guān)系具有重要的意義。(生物谷Bioon.com)
DOI: 10.1111/tpj.12024
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Replication factor C1 (RFC1) is required for double-strand break repair during meiotic homologous recombination in Arabidopsis
Yang Liu, Yingtian Deng, Gang Li, Jie Zhao*
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
