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Sichuan?XuEmail author Xicheng?Ai Zhaoyong?Sun Qiyuan?Zhang Xingkang?Zhang 《科学通报(英文版)》2002,47(2):108-111
Telomeres are protein-DNA complexes at the terminals of linear chromosomes, which protect chromosomal integrity and maintain
cellular replicative capacity. From single-cell organisms to advanced animals and plants, structures and functions of telomeres
are both very conservative. In cells of human and vertebral animals, telomeric DNA base sequences all are (TTAGGG)n. In the
present work, we have obtained absorption and fluorescence spectra measured from seven synthesized oligonucleotides to simulate
the telomeric DNA system and calculated their relative fluorescence quantum yields on which not only telomeric DNA characteristics
are predicted but also possibly the shortened telomeric sequences during cell division are implied. Oligonucleotide 5′-TTAGGGTTAGGG
holds a low relative fluorescence quantum yield and remarkable excitation energy innerconversion, which tallies with the telomeric
sequence of (TTAGGG)n. This result shows that telomeric DNA has a strong non-radiative or innerconvertible capability. 相似文献
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Keefe DL 《Cellular and molecular life sciences : CMLS》2007,64(2):115-116
Telomeres are important segments of chromosomes that protect chromosome ends from nucleolytic degradation and fusion. At meiosis
telomeres display an unprecedented behavior which involves their attachment and motility along the nuclear envelope. The movements
become restricted to a limited nuclear sector during the so-called bouquet stage, which is widely conserved among species.
Recent observations suggest that telomere clustering involves actin and/or microtubules, and is altered in the presence of
impaired recombinogenic and chromosome related functions. This review aims to provide an overview of what is currently known
about meiotic telomere attachment, dynamics and regulation in synaptic meiosis. 相似文献
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Scherthan H 《Cellular and molecular life sciences : CMLS》2007,64(2):117-124
Telomeres are important segments of chromosomes that protect chromosome ends from nucleolytic degradation and fusion. At meiosis telomeres display an unprecedented behavior which involves their attachment and motility along the nuclear envelope. The movements become restricted to a limited nuclear sector during the so-called bouquet stage, which is widely conserved among species. Recent observations suggest that telomere clustering involves actin and/or microtubules, and is altered in the presence of impaired recombinogenic and chromosome related functions. This review aims to provide an overview of what is currently known about meiotic telomere attachment, dynamics and regulation in synaptic meiosis. 相似文献
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G-四链体DNA是抗肿瘤药物研究开发的重要靶点,选择性识别并稳定G-四链体DNA的化合物是潜在的抗肿瘤药物.文章利用紫外可见吸收滴定,荧光滴定,CD光谱以及荧光共振能量转移熔点实验(FRET-melring)研究了三个基于邻菲罗啉的新型衍生物(A,B和C)与人端粒G-四链体DNA的相互作用.结果表明三个化合物通过末端堆积方式与G四链体DNA相互作用,结合常数(K)约为106 mol-1·L.当浓度为3 μmol·L-1时,化合物A,B和C分别使G四链体DNA熔点温度增加(△Tm)16.2,10.5和10.9℃.而且在10倍过量双螺旋DNA存在下均能选择性识别并稳定G-四链体结构. 相似文献
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孙毅 《科技情报开发与经济》2007,17(7):142-143
论述了端粒酶与癌症、转基因技术治癌、抗虫转基因作物培育、人工控制牛性别技术、转基因猪与人类器官移植以及超级杂交稻的研究现状,并对其产生的效益进行了分析。 相似文献
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Epigenetic reprogramming in mammalian nuclear transfer 总被引:3,自引:0,他引:3
LIShijie DUWeihua LINing 《科学通报(英文版)》2004,49(8):766-771
Somatic cloning has been succeeded in some species, but the cloning efficiency is very low, which limits the application of the technique in many areas of research and biotechnology. The cloning of mammals by somatic cell nuclear transfer (NT) requires epigenetic reprogramming of the differentiated state of donor cell to a totipotent, embryonic ground state. Accumulating evidence indicates that incomplete or inappropriate epigenetic reprogramming of donor nuclei is likely to be the primary cause of failures in nuclear transfer. This review summarizes the roles of various epigenetic mechanisms, including DNA methylation, histone acetylation, imprinting, X-chromosome inactivation, telomere maintenance and expressions of development-related genes on somatic nuclear transfer. 相似文献
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真核生物染色体末端复制,DNA聚合酶并不能完成,需要端粒酶来进行,在缺少端粒酶活性的情况下,细胞将发生衰老并直至死亡。在肿瘤细胞中,通过抑制端粒酶活性可达到治疗癌症的目的。构建具有端粒酶活性的反转录酶区表达载体,转化体细胞可获得永生细胞系,可以用于基因治疗和遗传学应用。 相似文献
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通过引入染色体端粒的概念, 建立了一维元胞自动机中染色体端粒的具有齐次性动力学演化方程, 进一步给出染色体长度以及染色体长度变化率的动力学方程. 相似文献