科研突破 亟须创新与合作

今年是生命遗传物质脱氧核糖核酸(DNA)双螺旋结构发现50周年纪念日。这一被视为20世纪生物学领域最重大成果的发现开辟了生物学新领域,不仅为人们从分子水平认识人类的遗传、发育、衰老以及生物体内部细胞结构、功能和运行模     

浅析DNA双螺旋结构发现的社会条件

介绍了DNA双螺旋结构发现的背景与经过,分析了DNA双螺旋结构发现的社会条件,论述了从DNA双螺旋结构的发现过程中获得的有益启示。     

DNA复制从何而起——揭示人类遗传物质传递关键步骤

生命的奥秘让人困惑而着迷,人们对于生命起源和本质的探索更是坚定执着,生生不息.正因为此,科学家们破解了一个又一个生命科学的谜团. 1952年,科学家从噬菌体侵染细菌的实验中确定了DNA是遗传物质,自此之后,DNA便成了生命科学领域光彩夺目的主角.紧接着,科学家沃森和克里克发现了DNA的双螺旋结构,揭示了DNA分子是由两...     

试论发现DNA双螺旋结构的模型方法

DNA双螺旋结构模型的发现是20世纪生命科学最伟大的成就.本文从DNA双螺旋结构发现的角度,对模型方法的应用、意义和原则等进行论述和探讨.     

DNA双螺旋结构模型对人类社会的影响

195 3年 ,美国遗传学家沃森 (Wetson)和英国物理学家克里克 (Crick)在英国《自然》(Natare)杂志上于 4月 2 5日发表论文 ,提出DNA双螺旋结构模型。这个发现宣告了分子生物学的诞生 ,在生命科学史上翻开了划时代的一页。给人类社会带来了巨大的影响。1　历史的回顾DNA双螺旋结构模型诞生五十年来 ,分子生物学领域出现了一系列激动人心的发现和突破 :195 6年美国生物化学家科恩伯格分离并提纯出了DNA聚合酶。 195 7年科恩伯格与美国生物化学家奥乔亚用人工合成的方法合成了DNA和RNA ,于 195 9年他们获得了诺贝尔生理学和医学奖。他们…     

科学家发现人类“灵魂细胞”

佛郎西斯·克里克和另一名科学家詹姆斯·沃森于1953年揭示出DNA双螺旋结构,1962年,两人因此获得了诺贝尔生理学及医学奖。DNA双螺旋结构的发现,标志着分子生物学基本理论框架的初步确立,此后科学家们普遍认为,在现代生命科学中,剩下需要解决的基础理论问题只有三个:即生命的起源、意识的产生和生命发育过程。多年来,克里克就一直致力于研究意识的产生,尤其致力于反驳灵魂存在学说。他认为,人的灵魂或意识根本不是先天就有的,而是由人体大脑中的一小组神经元细胞产生和控制的。他说:“我的科学信仰使我相信,我们的思想、意识完全可以用大脑中一些神经细胞的交互作用来解释。”不久前,他和他的研究小组通过大量实验终于发现了人类的“灵魂细胞”。     

量子生物学简介

十九世纪末,在物理学、化学发展的基础上,尤其是电子的发现、电子显微镜的发明和电子计算机的出现,使生物学从宏观现象的描述阶段转到细胞水平和亚细胞水平.二十世纪又进入了分子水平,这就使生物学跨入了近代科学的行列.1945年发现DNA(脱氧核糖核酸)分子空间构型的规律和1953年确定DNA的双螺旋结构,为量子生物学诞生提供了理论基础.量子生物学是用量子力学的原理来阐明生物大分子的结构及其功能,并进一步阐明细胞     

不再陌生的DNA——纪念DNA双螺旋结构发现60周年

 2013年是DNA双螺旋结构发现60周年.1953年沃森和克里克在英国《自然》杂志发表了DNA双螺旋结构的文章, 由此开启了分子生物学时代.60年来, 生命科学已经进入了后基因组时代——揭开基因的功能秘密, 蛋白质组学、功能基因组学等成为生命科学的热点.     

访DNA双螺旋结构的诞生地

最近世界各国都在纪念DNA双螺旋结构发现50周年。与今天人们对这一发现的赞誉相比,50年前双螺旋理论的诞生却不那么引人注目,它的诞生地更是一个很难和科学沾上边的小酒吧。     

生物技术研究的新进展(上)

40多年前,沃森(Watson.J.)和克里克(Crick.F)发现了DNA双螺旋结构.从此诞生了一门新学科—分子生物学.分于生物学一诞生.就以惊人的速度发展起来.成了本世纪最重要的学科之一。生物技术的研究也因此得到高速的发展。 一、人类首创具有生命活力的     

DNA打开生命之门 —— 遗传、发育与进化

DNA分子双螺旋结构的揭示直接引导现代生命科学的基础理论——中心法则建立。在过去的短短的50年中,生命科学发生了“脱胎换骨”的变化,几乎所有的传统生命科学分支学科都获得了长足的进步,许多新兴的生物学分支学科和边缘学科相继建立,生物学技术引发了社会产业结构的深刻变革,许多生物学观念也已经渗透到社会生活的各个方面,它所打开的探索生命奥秘之门将继续引领人们去挑战更多的未解的生命之谜。     

Nature,nurture and human disease

What has been learnt about individual human biology and common diseases 50 years on from the discovery of the structure of DNA? Unfortunately the double helix has not, so far, revealed as much as one would have hoped. The primary reason is an inability to determine how nurture fits into the DNA paradigm. We argue here that the environment exerts its influence at the DNA level and so will need to be understood before the underlying causal factors of common human diseases can be fully recognized.     

The digital code of DNA

The discovery of the structure of DNA transformed biology profoundly, catalysing the sequencing of the human genome and engendering a new view of biology as an information science. Two features of DNA structure account for much of its remarkable impact on science: its digital nature and its complementarity, whereby one strand of the helix binds perfectly with its partner. DNA has two types of digital information--the genes that encode proteins, which are the molecular machines of life, and the gene regulatory networks that specify the behaviour of the genes.     

DNA计算机

脱氧核糖核酸（简称DNA）是生物体内的一种具有双螺旋结构的遗传物质,用DNA可以进行运算,即构成的DNA计算机能很快地求解复杂的问题;以DNA编码为信息的载体,DNA计算机中的输入和输出设备都是DNA的,链用一系列二进制的数代表所求问题中的变量,用DNA中特有的寡核苷酸序列表示这些二进制的数,再将DNA利用分子生物和化学组装技术组装到芯片上,利用DNA杂交化学方法,排除各种代表不正确解的寡核苷酸序列,最后通过聚合酶链式反应（PCR）和各种检测技术读出保留在芯片上的DNA序列,读出的DNA序列所代表的二进制数即为所求问题的解,本文将从DNA运算过程入手,介绍DNA计算机的原理和DNA计算机的若干最新研究进展。     

The conformation of the DNA double helix in the crystal is dependent on its environment

Studies of the crystal structures of more than 30 synthetic DNA fragments have provided structural information about three basic forms of the double helix: A-, B- and Z-form DNA. These studies have demonstrated that the DNA double helix adopts a highly variable structure which is related to its base sequence. The extent to which such observed structures are influenced by the crystalline environment can be found by studying the same molecule in different crystalline forms. We have recently crystallized one particular oligomer in various crystal forms. Here we report the results of structural analyses of the different crystal structures and demonstrate that the DNA double helix can adopt a range of conformations in the crystalline state depending on hydration, molecular packing and temperature. These results have implications on our understanding of the influence of the environment on DNA structure, and on the modes of DNA recognition by proteins.     

Structure of an adenine-cytosine base pair in DNA and its implications for mismatch repair

Mutational pathways rely on introducing changes in the DNA double helix. This may be achieved by the incorporation of a noncomplementary base on replication or during genetic recombination, leading to substitution mutation. In vivo studies have shown that most combinations of base-pair mismatches can be accommodated in the DNA double helix, albeit with varying efficiencies. Fidelity of replication requires the recognition and excision of mismatched bases by proofreading enzymes and post-replicative mismatch repair systems. Rates of excision vary with the type of mismatch and there is some evidence that these are influenced by the nature of the neighbouring sequences. However, there is little experimental information about the molecular structure of mismatches and their effect on the DNA double helix. We have recently determined the crystal structures of several DNA fragments with guanine X thymine and adenine X guanine mismatches in a full turn of a B-DNA helix and now report the nature of the base pairing between adenine and cytosine in an isomorphous fragment. The base pair found in the present study is novel and we believe has not previously been demonstrated. Our results suggest that the enzymatic recognition of mismatches is likely to occur at the level of the base pairs and that the efficiency of repair can be correlated with structural features.     

Human DNA ligase I completely encircles and partially unwinds nicked DNA

The end-joining reaction catalysed by DNA ligases is required by all organisms and serves as the ultimate step of DNA replication, repair and recombination processes. One of three well characterized mammalian DNA ligases, DNA ligase I, joins Okazaki fragments during DNA replication. Here we report the crystal structure of human DNA ligase I (residues 233 to 919) in complex with a nicked, 5' adenylated DNA intermediate. The structure shows that the enzyme redirects the path of the double helix to expose the nick termini for the strand-joining reaction. It also reveals a unique feature of mammalian ligases: a DNA-binding domain that allows ligase I to encircle its DNA substrate, stabilizes the DNA in a distorted structure, and positions the catalytic core on the nick. Similarities in the toroidal shape and dimensions of DNA ligase I and the proliferating cell nuclear antigen sliding clamp are suggestive of an extensive protein-protein interface that may coordinate the joining of Okazaki fragments.     

回顾DNA双螺旋发现的里程碑意义

从研究资源分配的调整、研究模式的转变和对科学、技术与社会的影响三个方面讨论了DNA双螺旋模型提出的里程碑意义。提出科学与技术的进步是无可阻挡的,人类的理性之光总会驱走黑暗,为世界带来更加美好的明天。