DNA损伤应答与DNA双链断裂修复

在多种多样的生物体中，基因组保持完整具有极为重要的意义，它是细胞发挥功能和维持生存的必要条件。但是许多内源或外源因素如电离辐射（IR）、基因毒性剂、复制叉停止．核酸酶、减数分裂、免疫细胞V（D）J基因重排等，均可引起DNA损伤，破坏基因组的稳定性。DNA损伤发生频率很高．其中DNA双链断裂（DNA double strand breaks，DSBs）是最严重的DNA损伤，是细胞内多种类型的DNA损伤中最危险的一种，如何及时地感直DNA的损伤并进行修复．是至美重要的一个问题．     

DNA净化新技术

本文介绍了一种用玻璃粉从琼脂糖凝胶中回收DNA的方法.此技术基于在高浓度Nal存在时,琼脂糖的熔点大大降低,在45～55℃下琼脂糖就能溶解.当含有DNA的琼脂糖凝胶溶解后,释放出的DNA吸附于玻璃粉上,与蛋白质、RNA等成分分离.在低盐溶液或水溶液中,DNA从玻璃粉上解脱下来,从而达到净化的目的.此方法简便、经济、快速,DNA回收率可达70～80%.     

DNA损伤修复

为什么DNA损伤修复受到那么多的重视,分析起来可能有三方面原因:(1)从能源问题上看,人类面临寻找新的能源,无疑核能是最经济最干净的一种。将来工业用能源必然是核能占主要地位。     

电离辐射致DNA簇损伤中的DNA片段

细胞受照后DNA分子发生损伤的空间分布是其生物学效应的重要决定因素。本实验研究这种损伤的类型、程度、产率及修复。     

DNA组织在电离辐射诱发DNA损伤中的作用研究进展

DNA组织在电离辐射诱DNA损伤和修复中具有重要作用。细胞DNA的损伤程度和修复能力的大小与染色体包装、细胞核基质、细胞内可溶性蛋白、细胞周期、细胞形状及细胞间基质等因素有关。     

乙肝DNA疫苗研究进展

ＤＮＡ疫苗区别于血源怀和重组乙肝疫苗,前者利用ＨＢＶ核蛋白(ＮＰ)诱导特异的细胞毒性Ｔ淋巴细胞(ＣＴＬ)产生,从而发挥免疫作用。诱生的ＣＴＬ细胞不令可识别,还可杀伤相应病毒感染的靶细胞,所以还具有治疗作用。目前ＤＮＡ疫苗的研究取得一定进展,如核苷酸序列包含单链免疫刺激ＤＮＡ序列(ＩＳＳ),调控元件ＣＭＶ启动子,可提高接种效果的基因枪等。但由于ＤＮＡ可整合到窠宿主基因组,有诱发原癌基因活化和抑癌基因灭活的危险性,且有可能诱那里产生抗ＤＮＡ抗体或抗自身组织细胞抗体,产生特异免疫耐受,故未能在人群中使用。乙肝DNA疫苗…     

2型、5型腺病毒DNA与12型腺病毒DNA、大肠杆菌DNA序列的对比研究

目的通过对2型、5型人腺病毒DNA（Adv2、5 DNA）与Adv12 DNA及大肠杆菌DNA（EC DNA）序列进行对比研究，确定Adv2、5 DNA中能够拈抗细菌DNA的可能的活性片段——抑制性CpG寡核苷酸（CpG-N ODN）。方法从NCBI核酸数据库中获取Adv2、5、12 DNA和EC DNA序列，采用DNATools、BioEdit等软件对Adv2、5、12 DNA和EC DNA进行序列分析和比较，确定Adv2、5 DNA特征性的CpG基序，查找出Adv2、5 DNA中以上述CpG基序为核心的12碱基寡核苷酸（12-ODN）。结果确定了19种Adv2、5 DNA特征性的CpG基序，Adv2、5 DNA中以这19种CpG基序为核心的12-ODN共504条。结论504条12-ODN可能是Adv2、5 DNA的CpG-N ODN。     

DNA聚合酶β对DNA损伤的修复作用及其生物学进展

ＤＮＡ聚合酶β是由单条肽链组成的小分子蛋白，它的主要功能与ＤＮＡ损伤修复有关。本文就该酶的结构与催化反应、对ＤＮＡ辐射损伤的修复作用、生物学功能、基因结构以及调控成分等作较详细的介绍。     

Competition for DNA binding sites using Promega DNA IQ™ paramagnetic beads

The Promega DNA IQ? system is easily amenable to automation and has been an integral part of standard operating procedures for many forensic laboratories including those of the Royal Canadian Mounted Police (RCMP) since 2004. Due to some failure to extract DNA from samples that should have produced DNA using our validated automated DNA IQ?-based protocol, the competition for binding sites on the DNA IQ? magnetic beads was more closely examined. Heme from heavily blooded samples interfered slightly with DNA binding. Increasing the concentration of Proteinase K during lysis of these samples did not enhance DNA recovery. However, diluting the sample lysate following lysis prior to DNA extraction overcame the reduction in DNA yield and preserved portions of the lysates for subsequent manual or automated extraction. Dye/chemicals from black denim lysates competed for binding sites on the DNA IQ? beads and significantly reduced DNA recovery. Increasing the size or number of black denim cuttings during lysis had a direct adverse effect on DNA yield from various blood volumes. The dilution approach was successful on these samples and permitted the extraction of high DNA yields. Alternatively, shortening the incubation time for cell lysis to 30 min instead of the usual overnight at 56 °C prevented competition from black denim dye/chemicals and increased DNA yields.     

DNA甲基化与电离辐射效应

随着人类基因组计划的完成,表观遗传学开始成为关注的热点.DNA甲基化是研究最早且较深入的表观遗传学标志之一.越来越多的研究表明,DNA甲基化在肿瘤的发生及演进过程中起着重要的作用.笔者着重综述了DNA甲基化及电离辐射诱导的DNA甲基化改变,探讨在辐射致癌表观遗传学机制研究中的作用.     

DNA甲基化与电离辐射效应

随着人类基因组计划的完成,表观遗传学开始成为关注的热点.DNA甲基化是研究最早且较深入的表观遗传学标志之一.越来越多的研究表明,DNA甲基化在肿瘤的发生及演进过程中起着重要的作用.笔者着重综述了DNA甲基化及电离辐射诱导的DNA甲基化改变,探讨在辐射致癌表观遗传学机制研究中的作用.     

DNA甲基化与电离辐射效应

随着人类基因组计划的完成,表观遗传学开始成为关注的热点.DNA甲基化是研究最早且较深入的表观遗传学标志之一.越来越多的研究表明,DNA甲基化在肿瘤的发生及演进过程中起着重要的作用.笔者着重综述了DNA甲基化及电离辐射诱导的DNA甲基化改变,探讨在辐射致癌表观遗传学机制研究中的作用.     

登革病毒DNA疫苗的研究进展

目前登革病毒（ dengue virus ）感染已成为全球严重的公共卫生问题,亟待有效的疫苗进行特异性预防。与减毒活疫苗、灭活疫苗等传统疫苗相比,DNA疫苗具有制备简便、价格低廉、无感染风险、便于储运以及长效性好等特点,成为近年来登革病毒疫苗研究的热点。该文综述了登革病毒DNA疫苗构建策略、接种方式、免疫策略、免疫佐剂、免疫效果等方面的研究进展。     

鹿科动物线粒体DNA研究进展

线粒体DNA由于自身比较独特的遗传特性,已被广泛地用于鹿科动物(Cervidae)群体遗传学和系统学的研究.文中介绍了鹿科动物线粒体DNA的分子结构,综述了线粒体DNA在鹿科动物种群识别、起源与分化、保护生物学、系统地理学以及鹿茸鉴定的应用情况.     

The DNA‐Buster: The evaluation of an alternative DNA recovery approach

Touch DNA recovery techniques can have limitations, as their effectiveness depends on the substrate on which the DNA of a person of interest can be found. In this study, an in-house dry-vacuuming device, the DNA-Buster, was compared to traditional methods for its DNA recovery performance from items typically examined in forensic casework. The aim was to evaluate whether this dry-vacuuming approach can recover DNA efficiently, potentially complementing the well-established recovery strategies. For this, the performances of swabbing, taping, wet- (M-Vac®) and dry-vacuuming (DNA-Buster) were investigated quantitatively and qualitatively for touch DNA deposited on carpet, cotton sweater, stone, tile and wood. For the sweater, both vacuuming methods outperformed the other collection tools quantitatively. While the highest DNA amounts for the carpet were yielded by swabbing and taping, dry-vacuuming was equally good in reaching full DNA profiles, whereas less complete profiles were observed for the M-Vac®. For stone and tile, swabbing was optimal, whereas dry-vacuuming clearly underperformed for these substrates. Taping was the best recovery method for wood. Despite applying single donor DNA after thoroughly cleaning the items, undesired DNA mixtures were detected for all recovery techniques and all substrates. The overall research findings show first that the novel dry-vacuuming method is suited for DNA recovery from textiles. Secondly, they indicate that more attention should be paid to the substrate-collection dependency to ensure best practices in recovering genetic material in a precise, confident and targeted manner from the variety of forensic casework material.     

DNA甲基化与电离辐射效应

随着人类基因组计划的完成,表观遗传学开始成为关注的热点.DNA甲基化是研究最早且较深入的表观遗传学标志之一.越来越多的研究表明,DNA甲基化在肿瘤的发生及演进过程中起着重要的作用.笔者着重综述了DNA甲基化及电离辐射诱导的DNA甲基化改变,探讨在辐射致癌表观遗传学机制研究中的作用.     

Ku蛋白与DNA修复

电离辐射易引起DNA双链断裂(DSB),Ku蛋白作为异二聚体,主要参与非同源末端联接修复DSB。Ku蛋白在维持端粒结构发挥至关重要的作用。在人的不同肿瘤中,Ku蛋白有着异常表达,且Ku蛋白的表达和功能与肿瘤放化疗抵抗有关。通过抑制Ku蛋白可增强放化疗敏感性。因此,Ku蛋白可作为放化疗增敏的靶点。