【摘要】：第一部分：RNAi干擾途徑在各種生命活動中起著重要的調(diào)控作用。然而,在哺乳動物的有絲分裂過程中,RNAi干擾途徑是否參與染色體分離的問題至今還沒有定論。在本文中,我們發(fā)現(xiàn)兩個RNAi干擾途徑的關(guān)鍵因子(Dicer和AG02)直接參與調(diào)控染色體分離步驟。降低Dicer和AG02的表達(dá)水平會導(dǎo)致高比率的染色體分離滯后現(xiàn)象,而且這個效應(yīng)不依賴于miRNA通路。另外,我們還發(fā)現(xiàn)α-satellite RNA是人類中期染色體上的重要組成成分。過量積累在染色體上的α-satellite RNA會干擾著絲粒和動粒的形成與功能。進(jìn)一步的研究結(jié)果表明,Dicer和AG02通過調(diào)控α-satellite RNA在中期染色體上的水平和分布,從而保證CENPC1正確定位到著絲粒區(qū)域,最終確保有絲分裂時期的染色體可以正確分離。我們的研究成果闡明了哺乳動物中RNAi干擾通路在染色體分離中的功能以及功能機(jī)理,為RNAi干擾途徑的功能研究提供了嶄新的視角,為將來相關(guān)的科研目標(biāo)提供了新的方向。第二部分：非編碼RNA是生命活動中的關(guān)鍵調(diào)控因子。近幾年,科學(xué)家在人類和鼠類細(xì)胞中發(fā)現(xiàn)了一類具有封閉環(huán)狀結(jié)構(gòu)的環(huán)狀RNA,其中兩個環(huán)狀RNA定位于細(xì)胞質(zhì)中,扮演著miRNA海綿的角色,調(diào)控細(xì)胞質(zhì)中miRNA的水平含量。在本文中,我們發(fā)現(xiàn)了一類與RNA聚合酶II相結(jié)合的環(huán)狀RNA(Exon-intron circular RNA, EIciRNA)。EIciRNA包含內(nèi)含子序列,而且它們的側(cè)翼互補(bǔ)序列可以促進(jìn)它們的形成。另外,我們還發(fā)現(xiàn)EIciRNA通過RNA-RNA相互作用與U1 snRNP結(jié)合形成U1 snRNP-EIciRNA復(fù)合物,該復(fù)合體會與Pol Ⅱ復(fù)合體結(jié)合,進(jìn)而調(diào)控親本基因的轉(zhuǎn)錄效率。本文闡明了EIciRNA順式調(diào)控親本基因轉(zhuǎn)錄的分子機(jī)理,為基因表達(dá)調(diào)控這個龐大的研究領(lǐng)域提供了嶄新的思考角度。
[Abstract]:The first part: RNAi interference pathway plays an important role in the regulation of various life activities. However, whether the RNAi interference pathway is involved in chromosome segregation in mammalian mitosis is still uncertain. In this paper, we found that two key factors of RNAi interference pathway (Dicer and AG02) are directly involved in the regulation of chromosome segregation. Decreasing the expression level of Dicer and AG02 leads to a high rate of chromosome segregation lag, and this effect is independent of the miRNA pathway. In addition, we also found that 偽-satellite RNA is an important component of human metaphase chromosomes. Excessive accumulation of 偽-satellite RNA on chromosomes interferes with the formation and function of centromere and megasome. The further results showed that Dicer and AG02 regulated the level and distribution of 偽-satellite RNA on metaphase chromosomes, thus ensuring that CENPC1 was correctly located in the centromeric region and finally the chromosomes at mitotic stage could be separated correctly. Our research results clarify the function and mechanism of RNAi interference pathway in chromosome segregation in mammals, and provide a new perspective for the functional study of RNAi interference pathway, and provide a new direction for the related scientific research objectives in the future. The second part: non-coding RNA is the key regulatory factor in life activities. In recent years, scientists have found a class of circular RNA, with closed circular structure in human and mouse cells, two of which are located in cytoplasm and play the role of miRNA sponge, which regulates the level of miRNA in cytoplasm. In this paper, we found that a class of cyclic RNA (Exon-intron circular RNA, EIciRNA). EII) RNA combined with RNA polymerase II contains intron sequences, and their flanking complementary sequences can promote their formation. In addition, we also found that EIciRNA binds U1-snRNP through RNA-RNA interaction to form U1-snRNP-EIciRNA complex, which binds to Pol 鈪，

本文編號：2472668