基于COI序列快速鉴定花蓟马的DNA条形码芯片初探

利用DNA条形码信息研制DNA芯片,建立快速高效的花蓟马鉴定方法.以3种花蓟马属,共9个样本的COⅠ基因片段序列为研究材料,应用软件Primer Premier5搜索出9个样本的12种motif基因序列,应用这12种motif序列制作虚拟DNA条形码芯片.虚拟电子杂交20个样本的COⅠ基因片段序列.结果显示,设计的虚拟DNA芯片能够鉴定本研究中的3种花蓟马,利用DNACOⅠ基因片段,设计DNA芯片在理论上可行.     

DNA芯片制作原理及其杂交信号检测方法

文章讨论了DNA芯片的制作原理和杂交信号的检测方法。依其结构,DNA芯片可分为两种形式,DNA阵列和寡核苷酸微芯片。DNA芯片的制作方法主要有光导原位合成法和自动化点样法。DNA芯片与标记的探针或DNA样品杂交,并通过探测杂交信号谱型来实现DNA序列或基因表达的分析。适应于DNA芯片的发展,同时出现了许多新型的杂交信号检测方法。主要有激光荧光扫描显微镜、激光扫描共焦显微镜、结合使用CCD相机的荧光显微镜、光纤生物传感器、化学发生法、光激发磷光物质存储屏法、光散射法等。     

指甲游离缘的核DNA分型研究

为探讨指甲游离缘核DNA分型的可行性, 采集无关个体指甲游离缘样本10份, 分别以不同消化体系, 采用有机法、Chelex-100法,有机法结合Chelex-100法等3种方法提取指甲游离缘核DNA, AmpFlSTR IdentifierTM试剂盒复合扩增, ABI PRISM 3130自动遗传分析仪检测分析。结果显示：与对照血样比较,有机法结合Chelex-100法提取的样本核DNA均获得满意的STR分型, 有机法提取的样本核DNA可以进行STR分型, 但部分样本图谱峰值不均衡, Chelex-100法提取的样本核DNA不能分型或出现较多等位基因缺失。提示指甲游离缘可以进行成功地核DNA的分型, 有机法和有机法结合Chelex-100法提取的DNA质量都可成功检测, 其中以有机法结合Chelex-100法提取DNA的检测成功率最高。     

R环的形成及对基因组稳定性的影响

R-环是由一个RNA:DNA杂交体和一条单链状态的DNA分子共同组成的三链核酸结构。其中, RNA:DNA杂交体的形成起因于基因转录所合成的RNA分子不能与模板分开, 或RNA分子重新与一段双链DNA分子中的一条链杂交。在基因转录过程中, 当转录泡遇到富含G碱基的非模板链区或位于某些与人类疾病有关的三核苷酸卫星DNA时, 转录泡后方累积的负超螺旋可促进R环形成。同时, 新生RNA分子未被及时加工、成熟或未被快速转运到细胞质等因素也会催生R环。研究表明, 细胞拥有多种管理R环的方法, 可以有效地管理R环的形成和处理已经形成的R环, 以尽量避免R环对DNA复制、基因突变和同源重组产生不利影响。文章重点分析了R-环的形成机制及R环对DNA复制、基因突变和同源重组的影响, 并针对R-环诱导的DNA复制在某些三核苷酸重复扩增有关的神经肌肉退行性疾病发生过程中的作用进行了分析和讨论。     

液相杂交快速检测特异DNA

检测特异DNA片段的方法中,传统Southern blot技术由于其高度可重复性及能够显示条带大小的特性,一直是DNA检测的“黄金标准”.但是杂交时间长,步骤复杂,放射性污染等问题亟待解决.为了简化Southern blot,研究使用了一种液相杂交快速检测DNA的方法,即使用异硫氰酸荧光素(FITC)标记的dUTP掺入探针后,在溶液中与待检测DNA样本42℃下杂交,然后琼脂糖凝胶电泳检测荧光杂交信号.利用质粒为模板,优化了探针制作、杂交液组成、杂交时间和温度等参数.在FITC-dUTP∶ dTTP比例为1∶3、模板质粒浓度为50μg、1×杂交缓冲液(25 mmol/LTris,10mmol/L EDTA,8mmol/L Nacl,PH =8.0)中95℃变性5～9 min和42℃杂交3h的实验条件下,可检出1.2μg的质粒,探针灵敏度为7.3 ng/μl.这种方法不需要转膜,曝光,大大节约了时间,简化了操作,荧光检测也为该方法同时检测多色样本提供了可能,可广泛应用于核酸检测.     

DNA芯片及其在生命科学中的应用

对DNA芯片的发生、发展、技术特点及在生命科学中的应用作了回顾,结果表明DNA芯片通过DNA或RNA样品与阵列的的杂交,可用于基因测序、基因表达、新基因的发现、突变的检测等等领域,虽然DNA芯片目前存在着不足和缺陷,但它正成为基因组和后基因组研究的重要工具.     

DNA分析与基因组序列和植物系统学研究

从DNA杂交、RFLP分析、DNA的限制酶图谱分析等方面描述DNA分析技术在植物学研究中的应用,讨论了DNA分析技术与植物系统学的关系及分子数据的分析方法。并以高等植物为对象,从核DNA、叶绿体DNA和线粒体DNA三方面对植物分子系统学进行了论述。     

HPV检测早期筛查宫颈癌的临床意义——附妇科门诊2761例宫颈拭子HPV分析

目的探讨女性HPV DNA检测在宫颈癌防治方面的意义。方法应用DNA杂交技术对2 761例妇科门诊就诊者基因分型检测。结果 2 761例样本中,HPV感染有768例,阳性率27.82%,HPV感染人次972人次。检测高危型HPV（16,18,31,33,35,39,45,51,52,56,58,59,68）813人次,占感染总人次的83.64%;检出低危型HPV（6,11,42,43,44）73人次,占感染总人次7.51%;中国人群常见型HPV（53,66,CP8304）86人次,占感染总人次的8.85%。165例样本中包含了25种亚型的感染。结论 DNA杂交技术检测HPV基因分型,可一次检测多种亚型,有利于对HPV多重感染的诊断和宫颈癌的防治,可作为宫颈癌筛查的手段。     

DNA在鸟类分子系统发育研究中的应用

鸟类分子系统发育研究中常用的DNA技术有DNA杂交、RFLP和DNA序列分析等。DNA杂交技术曾在鸟类中有过大规模的应用,并由此诞生了一套新的鸟类分类系统。在鸟类的RFLP分析中,用的最多的靶序列是线粒体DNA。DNA序列分析技术被认为是进行分子系统发育研究最有效、最可靠的方法。在DNA序列分析中,线粒体基因应用最广泛,但由于其自身的一些不足,近年来,不少学者把目光投向了核基因,将线粒体基因和核基因结合起来进行系统发育研究。目前在鸟类分子系统发育中,应用较多的核基因是scnDNA,其内含子可以用于中等阶元水平的系统研究,而外显子主要用于高等阶元的系统研究。除了分子标记自身的问题之外,鸟类分子系统发育研究中还存在着方法上的问题,包括分子标记的选择,样本数量以及数据处理等。今后鸟类分子系统发育研究应该更加注重方法的标准化。     

DNA微阵列(或芯片)技术原理及应用

DNA微阵列或芯片(DNA microarray or chip)技术是近年发展起来的又一新的分子生物学研究工具.它是利用光导化学合成、照相平板印刷以及固相表面化学合成等技术,在固相表面合成成千上万个寡核苷酸探针,或将液相合成的探针由微阵列器或机器人点样于尼龙膜或硅片上,再与放射性同位素或荧光物标记的DNA或cDNA杂交,用于分析DNA突变及多态性、DNA测序、监测同一组织细胞在不同状态下或同一状态下多种组织细胞基因表达水平的差异、发现新的致病基因或疾病相关基因等多个研究领域.     

DNA chips: promising toys have become powerful tools.

DNA chips are glass surfaces that represent thousands of DNA fragments arrayed at discrete sites. Hybridization of RNA or DNA-derived samples to DNA chips allows us to monitor expression of mRNAs or the occurrence of polymorphisms in genomic DNA. The technology holds great promise for identifying gene polymorphisms that predispose man to disease, gene regulation events involved in disease progression, and more-effective disease treatments.     

基因芯片技术及其应用

基因芯片是近年来产生的一项生物高技术。它是利用原位合成或合成后交联法,将大量的核酸片段有规则地固定在固相支持物如载玻片、金属片、尼龙膜上,制成芯片,然后将要检测的样品用荧光素或同位素标记,再与做成的芯片充分杂交,通过对杂交信号的检测来分析样品中的信息。基因芯片技术已在基因表达水平的检测、基因点突变及多态性检测、DNA序列测定、寻找可能的致病基因和疾病相关基因、蛋白质作图、基因组文库作图等方面显示出了广阔的应用前景。     

DNA芯片技术研究进展

DNA芯片技术是近年来发展迅速的生物高技术 .其基本过程是采用寡核苷酸原位合成或显微打印手段 ,将大量探针片段有序地固化于支持物如硅芯片的表面 ,然后与扩增、标记的生物样品杂交 ,通过对杂交信号的检测分析 ,即可得出样品的遗传信息 .该技术不仅可以对遗传信息进行定性、定量分析 ,而且扩展到基因组研究和基因诊断等方面的应用 .尽管目前在硬件和软件上还面临一些困难 ,但其发展和应用的前景广阔 .     

Microarrays: The Technology,Analysis and Application

DNA microarray analysis represents one of the major advances leading to the development of functional genomics and proteomics. It involves the fabrication of DNA either by in situ or on‐chip photolithographic synthesis or by inkjet or microjet deposition, as microspots immobilized on the surface of miniaturized substrates like glass or membranes. The immobilized DNA molecules are then allowed to hybridize with labeled complementary DNA. The hybrid DNA so formed is read through scanning devices, such as fluorescence and radioactivity. Further, computational approaches, for example, normalization and clustering allow thousands of genetic parameters in a single experiment to be simultaneously analyzed. This review discusses the fundamental principles and data analysis of the microarray technology, while focusing on its application in gene expression analysis, genotyping for point mutation and diseases diagnostics.     

DNA chips: the future of biomarkers

DNA chips are small, solid supports such as microscope slides onto which thousands of cDNAs or oligonucleotides are arrayed, representing known genes or simply EST clones, or covering the entire sequence of a gene with all its possible mutations. Fluorescently labeled DNA or RNA extracted from tissues is hybridized to the array. Laser scanning of the chip permits quantitative evaluation of each individual complementary sequence present in the sample. DNA chip technology is currently being proposed for qualitative and quantitative applications, firstly for the detection of point mutations, small deletions and insertions in genes involved in human diseases or affected during cancer progression; secondly, to determine on a genome-wide basis the pattern of gene expression in tumors, as well as in a number of experimental situations. The extraordinary power of DNA chips will have a strong impact on medicine in the near future, both in the molecular characterization of tumors and genetic diseases and in drug discovery and evaluation. Quantitative applications will soon spread through all fields of biology.     

Impact of DNA chips on haematological oncology

As the Human Genome Project hurtles towards completion, DNA microarray technology offers the potential to open wide new windows into the study of genome complexity. DNA chips can be used for many different purposes, most prominently to measure levels of gene expression (messenger RNA abundance) for tens of thousands of genes simultaneously. But how much of this data is useful and is some superfluous? Can array data be used to identify a handful of critical genes that will lead to a more detailed taxonomy of haematological malignancies and can this or similar array data be used to predict clinical outcome? It is still too early to predict what the ultimate impact of DNA chips will be on our understanding of cancer biology. There are many critically important questions about this new field that are yet unaddressed. By the publication of this article, it is hoped that the technology of DNA chips will be opened up and demystified, and that additional opportunities for creative exploration will be catalysed.     

Initiation sites for human DNA replication at a putative ribulose-5-phosphate 3-epimerase gene

Replication of the human genome requires the activation of thousands of replicons distributed along each one of the chromosomes. Each replicon contains an initiation, or origin, site, at which DNA synthesis begins. However, very little information is known about the nature and positioning of these initiation sites along human chromosomes. We have recently focused our attention to a 1.1 kb region of human chromosome 2 which functioned as an episomal origin in the yeast Saccharomyces cerevisiae. This region corresponded to the largest exon of a putative ribulose-5-phosphate-3-epimerase gene (RPE). In the present study we have used a real-time PCR-based nascent strand DNA abundance assay to map initiation sites for DNA replication in in vivo human chromosomes around a 13.4 kb region encompassing the putative RPE gene. By applying this analysis to a 1-1.4 kb nascent strand DNA fraction isolated from both normal skin fibroblasts, and the breast cell line MCF10; we have identified five initiation sites within the 13.4 kb region of chromosome 2. The initiation sites appear to map to similar positions in both cell lines and occur outside the coding regions of the putative RPE gene.     

Quantitative analysis of DNA array autoradiographs

DNA arrays and chips are powerful new tools for gene expression profiling. Current arrays contain hundreds or thousands of probes and large scale sequencing and screening projects will likely lead to the creation of global genomic arrays. DNA arrays and chips will be key in understanding how genes respond to specific changes of environment and will also greatly assist in drug discovery and molecular diagnostics. To facilitate widespread realization of the quantitative potential of this approach, we have designed procedures and software which facilitate analysis of autoradiography films with accuracy comparable to phosphorimaging devices. Algorithms designed for analysis of DNA array autoradiographs incorporate 3-D peak fitting of features on films and estimation of local backgrounds. This software has a flexible grid geometry and can be applied to different types of DNA arrays, including custom arrays.