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DNA甲基化与去甲基化调控脂肪沉积的研究进展   总被引:2,自引:2,他引:0  
脂肪沉积是一个复杂的生物学过程,受遗传和表观遗传的调控作用。DNA甲基化和去甲基化是表观遗传修饰的重要方式,可通过与转录因子的相互作用或改变染色质的结构调控基因的表达,进而参与机体生长发育和细胞分化等重要的生命过程。动物脂肪沉积是脂肪细胞增殖分化和肥大的结果,脂肪细胞分化是由多能干细胞经前体脂肪细胞向成熟脂肪细胞转化的过程。相关研究表明,转录因子过氧化物酶体增殖物激活受体γ(peroxi-some proliferator activiated receptorγ,PPARγ)和CCAAT增强子结合蛋白家族(CCAAT enchancer binding proteinfamily,CEBPs)在脂肪沉积过程中起关键调控作用。近期研究发现,DNA甲基化可以通过调控脂肪形成过程中相关基因的表达而参与脂肪细胞的分化和脂肪组织的生长发育。去甲基化也可影响动物脂肪沉积过程,但其具体机制目前尚不清楚。作者主要介绍了DNA甲基化和去甲基化的定义、发生位点、生物学功能、参与DNA甲基化和去甲基化过程中的酶及其作用机制,概述了脂肪沉积过程及PPARγ、C/EBPα等转录因子在脂肪沉积过程中的调控作用,重点阐述了DNA甲基化和去甲基化对脂肪形成相关基因的表达和对脂肪细胞分化的影响,旨在为阐明脂肪沉积机制及改善动物肉质品质提供参考。  相似文献   
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Cytosine methylation/demethylation plays pivotal roles in regulating gene expression at a genome-wide level. However, limited reports are available to reveal correlating changes of cytosine methylation and proteomic expression in Brassica napus so far. Therefore, in the present study, global cytosine methylation and proteome were analysed in B. napus after cold treatment by methylation-sensitive amplified polymorphism (MSAP) and two-dimensional protein electrophoresis technology (2-DE). The results showed that the lowered genome-wide DNA methylation status was revealed after cold treatment, and about 0.88% of discrepancy in DNA methylation was detected between the non-flowering and flowering plants after cold treatment. Moreover, the 52 significantly up-regulated proteins emerged in comparison with the 36 down-regulated proteins, as well as the 14 proteins exclusively detected in the flowering plants. Intriguingly the 8 specifically expressed proteins in the non-flowering plants disappeared in the flowering plants with cold treatment. Therefore, these present data proved that the correlating changes of cytosine methylation and proteomic expression were evidenced under cold treatment in B. napus.  相似文献   
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A random sample of conidiospores ofErysiphe graminis f.sp.hordei was obtained from the atmosphere above Cambridge, England, by incubating them on barley seedlings exposed on three dates in 1985. The asexual progeny of each spore was tested for its response to a range of doses of a systemic triazole fungicide, triademenol. Principal components analysis of the data revealed that the majority of isolates had a distinct level of response to triadimenol, being resistant to triadimenol at the rate apoplied to seed commercially. The remaining isolates appeared either to be sensitive to the lowest dose of triadimenol used, or to have one of two intermediate levels of resistance. There was a significant increase in the frequency of isolates with higher levels of resistance to triadimenol during 1985. This is likely to have been a response to the continuing widespread use of demethylation inhibitor (DMI) fungicides by British farmers.  相似文献   
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DNA甲基化与去甲基化调控肌肉发育研究进展   总被引:2,自引:0,他引:2  
肌肉发育是一个复杂的生物学过程,其调控机制尚不完善。但近年来表观遗传修饰对肌肉发育的调控作用逐渐成为热点领域,研究发现DNA甲基化与去甲基化修饰对肌肉发生与发育起到重要的调控作用。肌肉干细胞特异位点通过DNA甲基化修饰,影响肌肉发育过程关键基因的表达,进而调控早期发育的生肌过程。本文主要围绕肌肉发育过程中DNA甲基化及去甲基化修饰的变化、重要的甲基转移酶和去甲基化酶以及营养物质通过DNA甲基化修饰影响肌肉发生的作用进行论述。  相似文献   
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实验以鸡马立克氏病脾脏淋巴瘤继代细胞系MDCC MSB 1和感染马立克氏病毒的鸡胚成纤维细胞(CEF)为主要试验材料,作为参考系也使用了鸡马立克氏病卵巢淋巴瘤继代细胞系MDCC JP1、MDCC JP2、MDCC HP1及MDCC HP2细胞。用Suothern斑点分子杂交放射自显影等方法,验证了MDCC MSB 1等细胞株DNA的转录区和非转录区都存在着甲基化现象。转录区甲基化程度高于非转录区。用5 氮胞苷可以阻断DNA甲基化,阻断效果在转录区最好。  相似文献   
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Fungicide resistance in Phaeoacremonium aleophilum, one of the most frequent fungal pathogens associated with grapevine trunk diseases, was investigated and found to exist in some isolates of the pathogen against a commercial formulation, Escudo®. The effect of this compound and its two active substances, carbendazim and flusilazole, was first evaluated on the mycelial growth of P. aleophilum. Escudo®-resistant isolates were estimated at a frequency of 24% in Spanish vineyards. Then, the two active substances were used individually to test their effect on mycelia growth of twelve single-spore cultures originating from six Escudo®-resistant isolates. Flusilazole (DMI-triazole) did not inhibit mycelia growth of any single-spore cultures of P. aleophilum. Carbendazim (benzimidazole) used alone allowed the growth of the same single-spore cultures that were also resistant to Escudo®. AFLP characterization of sensitive and resistant single-spore cultures showed genetic diversity within P. aleophilum isolates but no AFLP markers were associated with resistance. New primers set (L2/R1) were designed to partially amplify the exon 6 of the beta-tubulin gene of P. aleophilum. Two different point mutations resulted in glycine (GGC) or lysine (AAA) replacing the glutamic acid (GAG) at codon 198 of the beta-tubulin gene in some of the resistant single-spore cultures studied. Resistant single-spore cultures of P. aleophilum were shown to have different aggressiveness levels as sensitive single-spore cultures by inoculation of wood segments of Vitis vinifera in the presence and absence of fungicide.  相似文献   
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以鸡马立克氏病脾脏淋巴瘤继代细胞系MDCC-MBI(MSB1)为研究对象,用southern和northern斑点分子杂交放射自显影等方法,证明了5-氮胞苷可以阻断MSB1细胞DNA的甲基化,且去甲基化的DNA转录区和部分非转录区有特异增幅的转录产物mRNA,说明这些区基因转录活性上升。用5-氮胞苷处理MSB1细胞使其去甲基化后,该细胞DNA的内切酶Barn HⅠ区域对DNaseⅠ敏感性增高,该片段区的基因表达活性也增高。以上结果提示.DNA的去甲基化可以提高MDV的基因表达,进一步说明MDV DNA的甲基化在抑制MDV基因表达,维持MDV在淋巴瘤细胞株中潜伏感染状态可能起着重要作用。  相似文献   
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