单核苷酸多态性

单核苷酸多态性指基因组内特定核苷酸位置上存在两种不同的碱基,且最少一种在群体的频率不小于1％。由于其丰富、稳定、易实现分析的自动化,大规模的SNP鉴定和公共SNP数据库的建立已经开始。它作为一种全新的研究工具,希望利用它对复杂疾病基因进行大规模的连锁不平衡与相关分析,从而促进多基因疾病发病机理的研究和药物基因组学的发展。     

人类基因组单核苷酸多态性的研究进展

随着分子遗传学的进展 ,疾病遗传学研究从简单的单基因疾病转向复杂的多基因疾病 (如骨质疏松症、糖尿病、心血管疾病、精神性紊乱、各种肿瘤等 )与药物基因组学的研究。与前者相比 ,多基因性状或遗传病的形成 ,受许多对微效加性基因作用。这些不同基因构成的遗传背景中 ,可能有易感性主基因 (ｍａｊｏｒｇｅｎｅ)起着重要作用。它们同时还受环境因素的制约 ,彼此间相互作用错综复杂 ,所以任一基因的多态性对疾病发生仅起微弱的作用。鉴于此 ,需要在人类基因组中找到一种数目多、分布广泛且相对稳定的遗传标记。单核苷酸多态性 (ｓｉｎｇｌ…     

单核苷酸多态性在作物遗传及改良中的应用

单核苷酸多态性（single nucleotide polymorphism,SNP）是等位基因间序列差异最为普遍的类型,可作为一种高通量的遗传标记。已建立了PCR扩增目标序列及其产物测序和电子SNP（eSNP）等多种发现和检测SNP的方法。玉米和大豆等作物也已开展了SNP分析。一些栽培作物种质的多样性不断减少,其结果使连锁不平衡（linkage disequilibrium,LD）增加,这有利于目的基因座上SNP单元型（haplotype）与表型的相关性分析。SNP已在作物基因作图及其整合、分子标记辅助育种和功能基因组学等领域展示了广泛的应用价值。 Abstract:Single nucleotide polymorphism(SNP) is the most common type of sequence difference between alleles,which can be used as a kind of high-throughput genetic marker.Several different routes have been developed to discover and identify SNP.These include the direct sequencing of PCR amplicons,electronic SNP(eSNP) and so on.SNP assays have been made in many crop species such as maize and soybean.The elite germplasm of some crops have been narrowed in genetic diversity,increasing the amount of linkage disequilibrium(LD) present and facilitating the association of SNP haplotypes at candidate gene loci with phenotypes.SNP analysis has been broadly used in the field of plant gene mapping,integration of genetic and physical maps,DNA marker-assisted breeding and functional genomics.     

单核苷酸多态性研究进展及其在医学中的应用

单核苷酸多态性（single nucleotide polymorphism,SNP）是人类基因组中单个碱基的变异,其最低基因频率不低于1％,是被受关注的第三代多态性遗传标记,为医学、药学等研究提供了新的方向,其在复杂疾病、遗传病研究及法医中个体识别、亲权鉴定和药学研究方面都有重要作用,本文就其研究最新进展、应用及检测手段作一综述。     

海洋生物单核苷酸多态性基因分型技术的研究进展

单核苷酸多态性(single nucleotide polymorphism,SNP)是一类广泛分布于基因组中由单个碱基差异引起的DNA序列变异,SNP标记是第三代分子标记的代表。随着大规模测序技术的快速发展,大量的候选SNP位点被发现,候选SNP位点的发掘需要合适的分型技术。从等位基因分型机制、反应方式和检测等位基因方法等方面介绍当前海洋生物SNP分型技术的研究进展,以期为不同试验目的的研究选择合适的SNP分型技术提供参考。     

单核苷酸多态性检测技术的研究进展

单核苷酸多态性是指在基因组水平上单个核苷酸变异引起的一种DNA序列多态性。因其具有密度高,遗传稳定,易于进行自动化、规模化分析等优势它已成为第三代分子标记,因此其检测技术也在近几年得到了快速的发展。将对未知单核苷酸突变位点的检测方法和已知单核苷酸突变位点的检测方法这两部分的研究进展作一综述。     

单核苷酸多态性检测方法研究进展

：单核苷酸多态性（singlenucleotidepolymorphism,SNP）是指在基因组水平上由单个核苷酸的变异引起的一种DNA序列多态性。SNP作为第三代分子标记,具有数量多、分布广等特点,已成为人类后基因组时代的主要研究内容之一。单核苷酸多态性在医学研究、临床诊断、药物开发与合理用药、法医学、遗传学的发展方面具有重要意义。因此,建立高度自动化和高通量的SNP检测分析技术十分重要。各种SNP分型检测方法都由等位基因特异性的识别反应和等住基因识别产物的分析检测两个部分组成。本文系统的介绍了引物延伸反应、序列杂交反应、酶连接反应、酶切割反应、核酸链构象差异反应等SNP检测的等位基因特异性的识别原理,以及质谱、荧光共振和偏振信号、化学发光、毛细管电泳测序、生物传感器等分析检测手段,并简要介绍了相关识别原理和分析检测手段的优缺点及应用范围,并对SNP检测技术的发展进行了展望。     

单核苷酸多态性检测方法的研究进展

单核苷酸多态性（single nucleotide polymorphism, SNP）的研究已成为人类后基因组时代的主要内容之一。因此建立高度自动化和高通量的SNP检测分析技术十分重要。文章系统地介绍了最新发展的几种SNP检测技术的原理和检测平台,详细阐述了等位基因特异性杂交、内切酶酶切技术、引物延伸法、寡核苷酸连接反应等SNP检测原理,以及平板读数仪、基因芯片、微球阵列技术和质谱仪等检测平台,并对SNP高通量检测技术的发展进行了展望。     

中国汉族人群MASP2基因单核苷酸多态性的连锁不平衡和单体型分析

目的：探讨中国汉族人群甘露糖结合凝集素相关的丝氨酸蛋白酶（MASP2）基因单核苷酸多态性（SNP）的连锁不平衡和单体型,为相关研究提供更为详实的数据。方法：选取30例广州汉族无关个体,用重新测序的方法进行MASP2基因SNP的发掘,构建连锁不平衡（LD）模式,与HapMap公布的其他4个人群数据相比,并选择4个标签SNP（tagSNP）在232例北京汉族个体和291例广州汉族个体中分析MASP2的多态性和单体型。结果和结论：对MASP2的重测序共检测出16个SNP,LD分析显示来自中国不同地区人群的LD模式基本相同,与来自美国和日本的人群存在差异;北京和广州地区汉族人群tagSNP的等位基因和基因型频率分布不存在显著差异。     

单核苷酸多态性技术在鸡遗传变异中的研究及应用

单核苷酸多态性(SNP)是继限制性片段长度多态性、微卫星标记之后的第三代分子标记,通常呈双等位基因多态。本文从SNP的特点、SNP的发现与检测、SNP数据库、SNP的频率及其与表型的关系等方面简述了SNP在鸡遗传变异中的研究及应用进展。     

人类基因组SNPs的研究现状及应用前景

基因组DNA是生物体各种生理、病理性状的物质基础,人类DNA序列变异约90%表现为单核苷酸多态性(singlenucleotidepolymorphisms,SNPs),这是一种常见的遗传变异类型,在人类基因组中广泛存在,被认为是人类疾病易感性和药物反应的决定性因素。本文主要介绍了SNPs的分类及特点、人类基因组SNPs的研究现状、SNPs在实践中的应用,以及SNPs在遗传作图、医药、遗传易感性、个体化医疗等方面的研究前景,并探讨了当前SNPs研究中存在的问题。     

miRNA相关单核苷酸多态性

miRNA相关单核苷酸多态性(miRNA-related single nucleotide polymorphisms或mirSNP)是可以导致miRNA基因调控功能缺失或紊乱的一类功能型SNP的总称。不论是miRNA靶基因结合位点,还是miRNA基因或miRNA加工基因上的mirSNP,都有可能影响miRNA对靶基因的调控。miRNA基因及miRNA加工基因上的mirSNP主要通过阻碍miRNA的生物合成而发挥功能,而靶基因结合位点上的mirSNP主要通过导致自由能的改变或功能构象的消失,影响miRNA与靶序列结合而丧失其原有的调控功能。mirSNP大多位于人类基因组基因间区和内含子区,与包括肿瘤在内的众多复杂性疾病密切关联。mirSNP不论对于复杂性疾病发病机制研究还是诊疗预后分子标志的确定都具有极其重要的研究价值。     

Detection of single nucleotide polymorphisms

Single nucleotide polymorphism (SNP) detection technologies are used to scan for new polymorphisms and to determine the allele(s) of a known polymorphism in target sequences. SNP detection technologies have evolved from labor intensive, time consuming, and expensive processes to some of the most highly automated, efficient, and relatively inexpensive methods. Driven by the Human Genome Project, these technologies are now maturing and robust strategies are found in both SNP discovery and genotyping areas. The nearly completed human genome sequence provides the reference against which all other sequencing data can be compared. Global SNP discovery is therefore only limited by the amount of funding available for the activity. Local, target, SNP discovery relies mostly on direct DNA sequencing or on denaturing high performance liquid chromatography (dHPLC). The number of SNP genotyping methods has exploded in recent years and many robust methods are currently available. The demand for SNP genotyping is great, however, and no one method is able to meet the needs of all studies using SNPs. Despite the considerable gains over the last decade, new approaches must be developed to lower the cost and increase the speed of SNP detection.     

单核苷酸多态概述

单核苷酸多态ＳＮＰ是遍布于基因组中的一种ＤＮＡ序列变化类型,人类基因组中平均约每一千碱基中有一个。单核苷酸多态是一种双等位型多态,群体中出现的频率大于１％或２％者视为多态,低于１％或２％的则视为突变。由于其具有高信息量、高密度又便于自动化操作的特点,单核苷酸多态在遗传性疾病基因的克隆和药物的设计与开发方面具有广阔的应用前景。本文对单核苷酸的概念、特点、应用前景,及其研究应用的一些问题作一综述。     

Cytokine single nucleotide polymorphisms in Iranian populations

Cytokines are important immunomodulatory molecules involved in immune responses against microorganisms; they also have an important role in the setting of immune system disorders. Cytokine single nucleotide polymorphisms have been extensively studied in different, normal populations as well as in association with disease. Cytokine gene polymorphisms are potentially important as genetic predictors of disease susceptibility, clinical outcome, and as a tool for anthropological studies. In this study, samples have been collected from 455 healthy individuals located in different regions of Iran (Tehran, Yazd, Sistan and Balochistan). Allele and genotype frequencies of cytokine SNP, including: IL-1alpha, IL-1beta, IL-1R, IL-1RA, IL-2, IL-4, IL-4RA, IL-6, IL-10, IL-12, TNF-alpha, TGF-beta and IFN-gamma were investigated, using the PCR-SSP method. Allele frequencies in Tehran and Yazd populations were similar, except for TGF-beta. Allele frequencies in Sistani & Baloch populations were similar at all positions, except for IL-1beta at position of -511 and IFN-gamma genes at position UTR5644; there were some differences in allele frequencies comparing these populations with the Yazd population, including: IL-4, IL-6, IL-10, TGF-beta and TNF-alpha. Although some significant differences were observed for some cytokines, it seems that the cytokine gene polymorphism profile of the Iranian population is similar to that of Caucasians, particularly the Italian population.     

Linkage analysis using single nucleotide polymorphisms

We performed multipoint linkage analysis using 83 markers from the SNP Consortium (TSC) SNP linkage map in 3 regions covering 190 cM previously scanned with microsatellite markers and found to be linked to type 2 diabetes. Since the average linkage disequilibrium present in the TSC SNP marker clusters is relatively low, we assumed the intracluster genetic distances were a reasonable small nonzero distance (0.03 cM) and performed linkage analysis using GENEHUNTER PLUS and ASM linkage analysis software. We found that for the pedigree structures and missing data patterns in our samples the average information content in all three regions and the LOD score curves in two regions obtained from the TSC SNP markers were similar to results obtained from microsatellite marker maps with 10 cM average spacing. We also give an algorithm which extends the Lander-Green algorithm to permit multipoint linkage analysis of clusters of tightly linked markers with arbitrarily high levels of intracluster linkage disequilibrium.     

Applications of single nucleotide polymorphisms in crop genetics

The discovery of single nucleotide polymorphisms (SNPs) and insertions/deletions, which are the basis of most differences between alleles, has been simplified by recent developments in sequencing technology. SNP discovery in many crop species, such as corn and soybean, is relatively straightforward because of their high level of intraspecific nucleotide diversity, and the availability of many gene and expressed sequence tag (EST) sequences. For these species, direct readout of SNP haplotypes is possible. Haplotype-based analysis is more informative than analysis based on individual SNPs, and has more power in analyzing association with phenotypes. The elite germplasm of some crops may have been subjected to bottlenecks relatively recently, increasing the amount of linkage disequilibrium (LD) present and facilitating the association of SNP haplotypes at candidate gene loci with phenotypes. Whole-genome scans may help identify genome regions that are associated with interesting phenotypes if sufficient LD is present. Technological improvements make the use of SNP and indel markers attractive for high-throughput use in marker-assisted breeding, EST mapping and the integration of genetic and physical maps.     

Characterisation of single nucleotide polymorphisms in sugarcane ESTs

Commercial sugarcane cultivars (Saccharum spp. hybrids) are both polyploid and aneuploid with chromosome numbers in excess of 100; these chromosomes can be assigned to 8 homology groups. To determine the utility of single nucleotide polymorphisms (SNPs) as a means of improving our understanding of the complex sugarcane genome, we developed markers to a suite of SNPs identified in a list of sugarcane ESTs. Analysis of 69 EST contigs showed a median of 9 SNPs per EST and an average of 1 SNP per 50 bp of coding sequence. The quantitative presence of each base at 58 SNP loci within 19 contiguous sequence sets was accurately and reliably determined for 9 sugarcane genotypes, including both commercial cultivars and ancestral species, through the use of quantitative light emission technology in pyrophosphate sequencing. Across the 9 genotypes tested, 47 SNP loci were polymorphic and 11 monomorphic. Base frequency at individual SNP loci was found to vary approximately twofold between Australian sugarcane cultivars and more widely between cultivars and wild species. Base quantity was shown to segregate as expected in the IJ76-514 × Q165 sugarcane mapping population, indicating that SNPs that occur on one or two sugarcane chromosomes have the potential to be mapped. The use of SNP base frequencies from five of the developed markers was able to clearly distinguish all genotypes in the population. The use of SNP base frequencies from a further six markers within an EST contig was able to help establish the likely copy number of the locus in two genotypes tested. This is the first instance of a technology that has been able to provide an insight into the copy number of a specific gene locus in hybrid sugarcane. The identification of specific and numerous haplotypes/alleles present in a genotype by pyrophosphate sequencing or alternative techniques ultimately will provide the basis for identifying associations between specific alleles and phenotype and between allele dosage and phenotype in sugarcane.Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.     

Empirical Bayes analysis of single nucleotide polymorphisms

Background  

An important goal of whole-genome studies concerned with single nucleotide polymorphisms (SNPs) is the identification of SNPs associated with a covariate of interest such as the case-control status or the type of cancer. Since these studies often comprise the genotypes of hundreds of thousands of SNPs, methods are required that can cope with the corresponding multiple testing problem. For the analysis of gene expression data, approaches such as the empirical Bayes analysis of microarrays have been developed particularly for the detection of genes associated with the response. However, the empirical Bayes analysis of microarrays has only been suggested for binary responses when considering expression values, i.e. continuous predictors.