微卫星DNA标记技术及其在昆虫学上的应用

微卫星DNA标记作为一种多态性和稳定性高、重复性好、呈共显性的分子遗传标记技术,目前已被广泛应用于昆虫学的研究中。本文介绍了微卫星DNA标记的基本原理和特点,并综述了近年来该技术在昆虫种群遗传结构及分化、生物学特性与习性、遗传图谱的构建、基因定位以及系统发生等领域中的应用。     

微卫星DNA标记技术及其在遗传多样性研究中的应用

微卫星DNA的高突变率、中性、共湿性及其在真核基因组中的普遍性,使其成为居群遗传学研究、种质资源鉴定、亲缘关系分析和图谱构建的优越的分子标记。本研究系统介绍了微卫星DNA在结构和功能上的特点,并对微卫星DNA标记技术应用的遗传学机理和一般方法进行了扼要的阐述。另外,本研究还探讨了微卫星DNA标记技术在遗传多样性研究中的应用现状,并进一步提出其发展前景。     

微卫星DNA标记技术及其在昆虫学上的应用

综述微卫星DNA标记技术在昆虫特定基因定位、种群遗传结构及分化、近缘物种的区分、昆虫生态特性的系统进化以及微卫星基因图谱的绘制等领域中的应用。     

微卫星DNA标记开发技术进展及其在经济植物研究中的应用

微卫星分子标记技术被广泛应用于分子生物学研究中,具有多态性高、重复性好、共显性表达、杂合度高等特点,在种群遗传多样性、遗传图谱构建等领域发挥不可替代的作用。近年来,随着新一代高通量测序技术的进一步成熟,简单重复序列(simple sequence repeat,SSR)标记的开发技术与应用得到了进一步的发展。现主要对基于高通量测序的微卫星分子标记最新开发技术进行介绍,并从遗传多样性分析、遗传图谱构建、品种鉴定及分子辅助育种等方面,总结近年来SSR标记技术在经济植物研究中的最新应用,最后对SSR技术的应用前景进行展望,以期为利用微卫星技术进行经济植物研究提供参考。     

DNA分子标记技术及其在植物遗传多样性研究中的应用

本文阐述了ＤＮＡ限制性片段长度多态性、ＤＮＡ指纹图谱、单位点小卫星、单位点微卫星及随机扩增多态ＤＮＡ等主要的ＤＮＡ遗传标记技术的基本原理和方法．综述了不同ＤＮＡ标记的优缺点及其在植物遗传多样性研究中的应用前景．     

大麦基因组中的微卫星标记及其应用

微卫星是以少数几个核苷酸为单位多次串联重复的DNA序列,是一种简单序列重复(simple sequence repeats,SSR),两侧一般是保守序列。由于它具有多态性高、共显性、容易用PCR检测和结果稳定可靠等特点,因此是一种十分理想的分子标记。大麦的微卫星DNA随机分布于基因组中,平均每一个微卫星基因座有3～18个等位基因,最高可达37个。SSR标记已广泛用于分子遗传图谱的构建、遗传多样性研究、种质鉴定、主要性状基因的定位及分子标记辅助选择育种等。大多数SSR标记集中在着丝粒附近区域,1HL、5HL和6HS明显缺乏SSR标记。大麦的SSR标记还有待进一步的开发。 Microsatellite Markers and Applications in the Barley Genome FENG Zong-yun1,2,3,ZHANG Yi-zheng1,LING Hong-qing3 1.College of Life Sciences,Sichuan University,Chengdu 610065,China; 2.College of Agronomy,Sichuan Agricultural University,Ya'an 625014,China; 3.The State Key Laboratory of Plant Cell & Chromosome Engineering,Institute of Genetics & Developmental Biology,Chinese Academy of Sciences,Beijing 100101,China Abstract:Microsatellites,also called simple sequence repeats (SSR),are simple,tandemly repeated DNA sequences with a repeat length of a few base pairs,and are very ideally used as molecular markers because of their abundance,high level of polymorphism,co-dominance and ease of assay with the polymerase chain reaction (PCR) by selecting primers as the conserved DNA sequences flanking the SSRs,as well as better stability.The experiments showed that SSRs are randomly distributed throughout the barley genome,and there are 3~18 alleles at a single SSR locus,up to 37 alleles/locus.SSR markers have being widely applied in the construction of molecular genetic map,the study of genetic diversity,the identification of germplasm,gene mapping for important traits and molecular marker-assisted selection.Meanwhile,most of markers are strongly clustered around the centromeric regions of all seven linkage groups.As a result of the clustering,genome coverage with SSRs remains incomplete with an obvious lack of markers on the long arms of chromosomes 1H and 5H and short arm of chromosome 6H.Therefore,it is very potential and necessary to further develop SSR markers in barley. Key words：barley;microsatellite marker;simple sequence repeats;genetic diversity;molecular mapping     

微卫星DNA在分子遗传标记研究中的应用

随着种群遗传学的发展 ,分子遗传标记特别是微卫星标记已经成为研究种群遗传的有力工具。本文就微卫星遗传标记的研究背景、技术应用以及优势与不足等方面进行了综述。     

DNA分子标记技术在生态学研究中的应用

分子生物学几种常见的分子标记技术如RFLP,RAPD,微卫星法,DNA序列分析使生态学研究从宏观步入了微观领域,极大的推动了生态学的发展,对这几种分子标记技术在生态学中的应用及其进展进行了综述,并比较了这些分子生物学技术各自的优缺点.     

DNA分子标记技术在植物种质资源鉴定中的应用

DNA分子标记技术从基因水平进行标记,不受环境因素、个体发育阶段及组织部位影响,多态性强,已成为生物学主要遗传标记手段之一。综述了几种主要DNA分子标记技术的原理和优缺点,着重阐述了其在植物种质资源鉴定方面的应用。     

分子标记技术在苹果育种中的应用

DNA分子标记是现代分子生物学发展出来的一类重要的遗传标记,已广泛应用于遗传图谱的构建、种质资源的管理和鉴定、基因的定位与克隆等。综述了分子标记在苹果育种中的应用。     

分子标记在家畜遗传多样性研究中的应用

家畜遗传多样性是生物多样性的重要组成部分,与人类未来的生存与发展密切相关。中国拥有丰富的地方家畜品种资源,但由于保种不当和盲目引进外来品种进行杂交、资金缺乏等原因,许多品种已濒临灭绝。如何保存利用好我国优良的家畜遗传资源已成为越来越严峻的问题。随着生物学技术的不断发展与完善,许多分子标记技术已经应用于畜禽遗传资源的研究。简要介绍了在家畜遗传多样性研究中应用最广的几种分子标记及其特性,讨论了在家畜遗传多样性的研究中如何选用适当的分子标记。     

DNA分子标记在木耳属真菌中的应用研究进展

介绍了目前已在木耳属真菌中广泛应用的几种DNA分子标记技术(RFLP、RAPD、AFLP、ISSR、SRAP、SCAR、ITS、IGS),以及这些标记在木耳属真菌系统发育、分类研究、种间和种内鉴定、遗传多样性分析等方面的应用,并展望了这些标记技术在木耳属真菌中的应用前景。     

Conservation of (GA)n microsatellite loci between Quercus species

Microsatellite (simple sequence repeat, SSR) amplification was performed in eight different members of the Fagaceae family by using sets of primers developed from sessile oak, Quercus petraea . In total, 136 cases of heterologous amplification were carried out, and 66% resulted in interpretable amplification products. From these, 12 PCR amplification products were sequenced and all 12 contained a sequence homologous to the original locus from Q. petraea . Although SSR primers worked even across different genera, with increasing evolutionary distance there was a clear tendency for decreasing ability to successfully amplify loci and a decreasing proportion of polymorphism amongst those markers which could be amplified. Two of the loci, ssrQpZAG46 and ssrQpZAG110, were polymorphic in all Quercus species tested. Only at one locus, ssrQpZAG58, a specific PCR product could be amplified in all species analysed. For four loci found in two species, we observed significant interspecies differences in the size range of the amplified alleles. Sequence analysis of two alleles showed that the size differences are not only due to variations in the number of (GA) repeats but also to an insertion of approximately 80 nucleotides in the flanking region. Our findings prove the usefulness of SSR markers within and amongst closely related genera of plants.     

Identification and characterization of expressed sequence tags‐derived simple sequence repeats markers from robusta coffee variety ‘CxR’ (an interspecific hybrid of Coffea canephora × Coffea congensis)

SSR (simple sequence repeats) markers derived from ESTs (expressed sequence tags), commonly called EST‐SSRs or genic SSRs provide useful genetic markers for crop improvement. These are easy and economical to develop as by‐products of large‐scale EST resources that have become available as part of the functional genomic studies in many plant species. Here, we describe for the first time, nine genic‐SSRs of coffee that are developed from the microsatellite containing ESTs from a cDNA library of moisture‐stressed leaves of coffee variety, ‘CxR’ (a commercial interspecific hybrid between Coffea congensis and Coffea canephora). The markers show considerable allelic diversity with PIC values up to 0.70 and 0.75 for Coffea arabica and Coffea canephora, respectively, and robust cross‐species amplification in 16 other related taxa of coffee. The validation studies thus demonstrate the potential utility of the EST‐SSRs for genetic analysis of coffee germplasm.     

Characterization of Fusarium poae Microsatellite Markers on Strains from Switzerland and Other Countries

Fusarium poae is a pathogen of increasing importance within the disease complex Fusarium head blight (FHB). Eleven microsatellite markers were developed, and 72 F. poae strains from Switzerland and other countries were used to assess the level of marker polymorphism. The number of alleles for each of the markers ranged from 4 to 15, and the average gene diversity was 0.62, ranging from 0.25 to 0.84. Using these novel markers, 44 genotypes could be differentiated among all F. poae strains. Two genotypes were represented by nine and ten strains, respectively, deriving from distinct geographic areas within Switzerland and indicating a potential selection advantage. Four markers were F. poae‐specific, whereas seven markers also yielded amplification products in one to four strains of five other Fusarium species. Of the latter, five markers revealed F. poae‐specific allele size ranges. Hence, these microsatellite markers could be used both for FHB species differentiation and for intra‐specific distinction of F. poae strains.     

Microsatellites for ecologists: a practical guide to using and evaluating microsatellite markers

Recent improvements in genetic analysis and genotyping methods have resulted in a rapid expansion of the power of molecular markers to address ecological questions. Microsatellites have emerged as the most popular and versatile marker type for ecological applications. The rise of commercial services that can isolate microsatellites for new study species and genotype samples at reasonable prices presents ecologists with the unprecedented ability to employ genetic approaches without heavy investment in specialized equipment. Nevertheless, the lack of accessible, synthesized information on the practicalities and pitfalls of using genetic tools impedes ecologists' ability to make informed decisions on using molecular approaches and creates the risk that some will use microsatellites without understanding the steps needed to evaluate the quality of a genetic data set. The first goal of this synthesis is to provide an overview of the strengths and limitations of microsatellite markers and the risks, cost and time requirements of isolating and using microsatellites with the aid of commercial services. The second goal is to encourage the use and consistent reporting of thorough marker screening to ensure high quality data. To that end, we present a multistep screening process to evaluate candidate loci for inclusion in a genetic study that is broadly targeted to both novice and experienced geneticists alike.     

A High Through-put Procedure for Capturing Microsatellites from Complex Plant Genomes

A method is outlined for large-scale isolation and characterization of microsatellite sequences from complex plant genomes. The method presented here differs from the previously published procedures in the use of randomly sheared (nebulized) genomic DNA for adapter-ligation, rigorous removal of biotinylated oligos, and high-density colony blots for constructing enriched libraries. Using this method we have constructed cotton microsatellite enriched libraries with over 20% (high stringency screening) or 75% (by random sequencing). Thus far we have identified and sequenced over 500 cotton microsatellites using this procedure. The procedure can be used to generate enriched SSR libraries from genomic DNA in about one week. High throughput screening and automated DNA sequencing can be accomplished in less than one month.     

Microsatellites reveal genetic diversity in Rotylenchulus reniformis populations

Rotylenchulus reniformis is the predominant parasitic nematode of cotton in the Mid South area of the United States. Although variable levels of infection and morphological differences have been reported for this nematode, genetic variability has been more elusive. We developed microsatellite-enriched libraries for R. reniformis, produced 1152 clones, assembled 694 contigs, detected 783 simple sequence repeats (SSR) and designed 192 SSR-markers. The markers were tested on six R. reniformis cultures from four states, Texas, Louisiana, Mississippi and Georgia, in the USA. Based on performance we selected 156 SSR markers for R. reniformis from which 88 were polymorphic across the six reniform nematode populations, showing as the most frequent motif the dinucleotide AG. The polymorphic information content of the markers ranged from 0.00 to 0.82, and the percentage of multiallelic loci of the isolates was between 40.9 and 45.1%. An interesting finding in this study was the genetic variability detected among the three Mississippi isolates, for which 22 SSR markers were polymorphic. We also tested the level of infection of these isolates on six cotton genotypes, where significant differences were found between the Texas and Georgia isolates. Coincidentally, 62 polymorphic markers were able to distinguish these two populations. Further studies will be necessary to establish possible connections, if any, between markers and level of pathogenicity of the nematode. The SSR markers developed here will be useful in the assessment of the genetic diversity of this nematode, could assist in management practices for control of reniform nematode, be used in breeding programs for crop resistance, and help in detecting the origin and spread of this nematode in the United States.