發(fā)布時間：2018-06-16 12:22

  本文選題：杜氏鹽藻 + 核基質(zhì)結(jié)合區(qū)��； 參考：《鄭州大學(xué)》2005年博士論文

【摘要】：核基質(zhì)結(jié)合區(qū)(matrix attachment regions, MARs)又叫核骨架附著區(qū)(scaffold attachment regions, SARs)是染色質(zhì)被限制酶消化后仍與核基質(zhì)或核骨架結(jié)合的DNA序列。MAR長度由300bp至2,000bp不等,通常富含AT堿基對,常含有一些特征性基序(motifs),如A-box(AATAAAAA/CAA)、T-box(TTTTATTTTT)、酵母自主復(fù)制序列(autonomously replicating DNA sequence, ARS)、果蠅拓樸異構(gòu)酶Ⅱ(Topoisomerase Ⅱ)識別位點和能形成蛋白質(zhì)識別位點的松散DNA(unwinding DNA)、彎曲DNA(curved DNA)等。MARs與核基質(zhì)結(jié)合受AT區(qū)的位置及結(jié)構(gòu)影響,其二級結(jié)構(gòu)表現(xiàn)為狹窄的DNA小溝,易于彎曲和解鏈。MAR一般位于功能轉(zhuǎn)錄單位的側(cè)翼,作為一種邊界元件(boundary elements),但也有一些MAR位于某些基因的內(nèi)含子中。雖然MAR具有一些序列特征,但比較不同MAR的堿基序列,發(fā)現(xiàn)MAR在堿基組成上并不具保守性。近年來研究發(fā)現(xiàn),將MAR構(gòu)建表達載體能提高外源基因的表達水平,增強外源基因表達的穩(wěn)定性,克服外源基因沉默等。MAR還能使染色質(zhì)形成環(huán)狀結(jié)構(gòu),還可以作為DNA復(fù)制的起始點或調(diào)控基因的轉(zhuǎn)錄。但關(guān)于MAR的研究尚處于早期階段,其分子調(diào)控機制目前仍不清楚。 迄今已有一些MAR從酵母、動物、植物及人類中分離出來,并進行了其功能的相關(guān)研究,但目前所分離的MAR絕大多數(shù)來源于高等動植物,單細胞的真核生物研究的較少,真核藻類的MAR研究未見相關(guān)報道。高等動植物存在器官組織分化問題,不同的分化組織細胞基因表達的方式及其種類不同,MAR序列也可能存在差別。因此以單細胞的真核生物研究MAR的調(diào)控機制更具有特點及優(yōu)勢。杜氏鹽藻(Dunaliella salina)是一種無細胞壁的單細胞綠藻,含有一個大的杯狀葉綠體進行光合作用,具鞭毛,能游動,可在0.05～5M NaCl培養(yǎng)液中
[Abstract]:Nuclear matrix attachment regions (Mars), also known as scaffold attachment regions (Sars), are the sequences of chromatin that bind to nuclear matrix or nuclear skeleton after digestion by restriction enzymes. Mar length ranges from 300bp to 2000bp, and is usually rich in AT base pairs. It often contains some characteristic motifs, such as A-box A / CA A T T T, yeast autonomous replicating sequence, arsiella, Drosophila topoisomerase II) recognition sites, loose DNAs that form protein recognition sites, curved DNAs, and so on. Mars binds to nuclear matrix. The location and structure of AT area, Its secondary structure is a narrow DNA groove, which is easy to bend and unchain. Mar is generally located on the flank of the functional transcription unit as a boundary element, but some Mar is also located in the introns of some genes. Although Mar has some sequence characteristics, it is found that Mar is not conserved in base composition by comparing the sequences of different Mar bases. In recent years, it has been found that constructing expression vector of Mar can improve the expression level of exogenous gene, enhance the stability of exogenous gene expression, overcome the silencing of exogenous gene, and make chromatin form circular structure. It can also act as the starting point of DNA replication or regulate the transcription of genes. However, the study of Mar is still in its early stage, and its molecular regulation mechanism is still unclear. Up to now, some Mar has been isolated from yeast, animal, plant and human, and its function has been studied. The Mar study of eukaryotic algae has not been reported. Higher plants and animals have the problem of organ tissue differentiation, and the gene expression patterns and their types of genes in different differentiated tissues and cells may also be different. Therefore, the study of the regulation mechanism of Mar by single cell eukaryote has more characteristics and advantages. Dunaliella Salina (Dunaliella Salina) is a single-celled green algae with no cell wall. It contains a large goblet chloroplast for photosynthesis, flagellum, swimming, and can be found in 0.05m NaCl medium.
【學(xué)位授予單位】：鄭州大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2005
【分類號】：R346

【引證文獻】

相關(guān)碩士學(xué)位論文 前2條

1 張翅;杜氏鹽藻（Dunaliella salina）cDNA文庫構(gòu)建及表達序列標(biāo)簽分析[D];華中科技大學(xué);2009年

2 張翅;杜氏鹽藻（Dunaliellasalina）cDNA文庫構(gòu)建及表達序列標(biāo)簽分析[D];華中科技大學(xué);2009年

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本文編號：2026648