恒河猴与食蟹猴微卫星DNA多态性的比较分析

目的分析恒河猴和食蟹猴群体间的遗传多样性,确立一种对恒河猴和食蟹猴种群个体的遗传鉴别方法。方法利用聚合酶链反应（PCR）扩增技术采用15个多态性微卫星DNA位点对50只恒河猴和50只食蟹猴个体进行了DNA多态性的分析,对比两群体间等位基因数目差异。结果筛选的15个具有显著多态性的微卫星DNA位点对恒河猴和食蟹猴种群可以进行DNA多态性分析,其等位基因数目均在7个以上,且两群体间有11个位点的等位基因数存在一定的差异。结论利用这些多态性微卫星DNA位点建立一种有效鉴别恒河猴和食蟹猴种群遗传背景的方法具有一定的可行性。     

树鼩微卫星DNA的多态性研究

目的探索并建立一种检测树鼩群体遗传多样性的方法。方法利用聚合酶链反应（PCR）扩增技术对30只树鼩个体的11个微卫星位点进行了遗传检测。结果所选的11个微卫星DNA位点中,有9个具有高度多态性,2个微卫星DNA位点多态性较差。结论所研究的树鼩微卫星位点中,有9个符合遗传标记特点,可用于检测树鼩群体的遗传多样性。     

食蟹猴微卫星DNA标记遗传监测及多态性分析

目的研究国内食蟹猴种群的遗传背景特性,建立食蟹猴种群遗传质量监测方法。方法采用微卫星DNA遗传标记技术对50只食蟹猴种群个体进行遗传质量监测及DNA多态性分析。结果从100个微卫星DNA位点中筛选出20个多态性高的位点,其食蟹猴种群个体的等位基因数目为5-10条,个体间均呈现高度的多态性;其观察等位基因数（Na）为5.0～10.0,有效等位基因数（Ne）为4.6118～8.3404,基因多样性（H）为0.7832～0.8801和香隆信息指数（I）为1.5651～2.1592。结论本实验有效地分析了食蟹猴种群的遗传多态性,为今后筛选特异性微卫星位点来建立食蟹猴种群遗传质量监测方法提供了理论依据。     

微卫星DNA与生化标记分析对长爪沙鼠群体遗传分析的比较

目的比较生化标记和微卫星DNA标记方法对长爪沙鼠群体遗传分析的可靠性。方法应用27个生化位点和13个微卫星DNA位点,采用已建立的生化标记和微卫星DNA标记分析方法对国内2个长爪沙鼠群体进行遗传分析,计算并比较两种方法测得的各群体遗传参数。结果生化基因位点中有13个位点在整体中呈现遗传多态性,多态率为48.1%;微卫星位点中有11个位点在整体中表现出多态性,多态率均为84.6%。两种方法测得的平均有效等位基因数趋于一致,微卫星DNA的多态位点百分率和平均杂合度均明显高于生化标记方法。但生化标记和微卫星DNA检测对两个长爪沙鼠群体的遗传多样性差异反映一致,所反映的群体平衡状况也基本一致。结论生化标记分析和微卫星DNA方法均可较好地反映长爪沙鼠群体遗传结构。     

西藏小型猪线粒体D-loop区及微卫星多态性的遗传学分析

目的通过分析西藏小型猪线粒体控制区(D-loop区)及微卫星位点的遗传多态性,检测西藏小型猪的遗传背景,从而为其作为实验动物提供分子生物学方面的可靠依据。方法利用特异性引物对西藏小型猪的线粒体D-loop区及10个具有多态性的微卫星位点进行扩增,割胶纯化并对线粒体D-loop区进行测序,另外采用聚丙烯酰胺凝胶电泳的方法分离微卫星位点的等位基因。结果西藏小型猪线粒体D-loop区全序列没有多态性,微卫星位点则具有高度的遗传多态性和杂合度,分别为0.584和0.573。结论西藏小型猪线粒体基因组无多态性,证明其在母系进化和遗传上与其他猪种较为一致,本实验所用的西藏小型猪生长于一个封闭的环境,导致其微卫星位点遗传多态性的中低度水平。     

应用微卫星标记对海南和广西恒河猴遗传多样性的研究

本研究利用11个微卫星位点,对海南和广西恒河猴进行了遗传检测,并通过POPGEN32软件计算各个微卫星座位的等位基因频率、有效等位基因数目(Ne)、多态信息含量(PIC)和遗传杂合度(H)。结果表明,所选择的11个微卫星位点均存在高度的遗传多态性,H为0.6848~0.河河猴的Ne、PIC和H的平均值均高于海南猴,分别为4.2583、0.7090、0.7706和4.2054、0.7025、0.7656,这种差别可能与地域来源有关。这些研究为微卫星标记分析恒河猴遗传多样性提供理论基础。     

PCR扩增近交系大鼠微卫星位点DNA多态性的研究

本实验选取大鼠7条染色体上的微卫星位点合成了10对引物,利用聚合酶链反应（PCR）扩增技术对国内北京和哈尔滨等4家单位提供伯6个品系（SHR、SHRSP、LEW、RCS、WKY和F344）的8个近交系大鼠群体进行了DNA多态性分析的研究。结果表明：9个微卫星位点具有显多态性;不同品系个体之间具有多态性;同一群体不同个体之间除SHR（哈）的SMST位点和WKY（哈）的AGT位点出现一定的差异,其他均没有差异;不同地区同一品系的不同个体之间也存在一定的差异。该方法能有效地对近交系与杂交系、品系与品系、品系与亚系加以区分。因此,本实验为开展近交系大鼠遗传作图、基因定位和为实验动物的遗传背景监测提供可靠的信息,为大鼠遗传基因的研究提供了一个快速简例、特异准确的方法。     

豚鼠基因组26个多态性微卫星标记的筛选

目的筛选豚鼠基因组的多态性微卫星标记,为豚鼠遗传质量控制及基因定位等工作奠定基础。方法采用磁珠富集法和豚鼠基因组数据库筛选法获取微卫星位点序列,通过分析和初步筛选,挑选部分候选位点,根据其序列设计引物,对5种不同来源的豚鼠基因组DNA标本进行PCR扩增,以期获得多态性分子标记。结果本实验采用磁珠富集法共获得微卫星序列304个,设计引物125对,最终获得多态性位点1个,暂未发现多态性的特异性位点17个;用数据库筛选法共获得微卫星序列292个,设计并合成相应引物178对,最终发现多态性位点25个,暂未发现多态性的特异性位点28个。结论本实验获得26个多态性微卫星标记,45个潜在的候选标记,为微卫星标记在豚鼠遗传质量监测及突变基因定位等工作的应用奠定了基础。     

草鱼连续两代的雌核发育群体及湘江流域群体基因组DNA的微卫星比较分析

对湘江流域草鱼群体,一代及连续两代极体型人工诱导雌核发育草鱼群体基因组DNA的微卫星引物统计分析结果表明:湘江流域草鱼群体存在一定程度的遗传多态性;大多数被检测的微卫星位点上存在两个以上的等位基因,但遗传多样性程度较低。一代人工诱导雌核发育草鱼群体中个体的基因位点已基本纯合,但就整个群体而言,个体之间的基因型还不完全一致,表现出一定的多态性。连续两代人工诱导雌核发育草鱼群体中不仅所检测个体的基因位点已完全纯合,并且各个体的基因型也完全相同。这些观察结果说明所检测的两代人工诱导雌核发育草鱼群体是纯合的,经连续两代人工诱导雌核发育可能建立起草鱼纯系。该实验结果还发现不仅草鱼的微卫星位点上存在等位基因的多态性,而且微卫星位点本身也存在多态性;在人工诱导草鱼雌核发育的过程中不仅存在微卫星等位基因快速丢失的现象,而且也存在微卫星位点丢失的现象。因此,加强对自然水体中草鱼种质资源多样性的保护和利用各种现代生物学技术纯化、筛选和组合优良性状基因,是草鱼遗传育种中同样重要和不可或缺的两个方面。     

大鸨东方亚种遗传多样性的微卫星分析

为了探索东方亚种数量正在减少的原因和制定科学、有效的保护措施,利用微卫星DNA对大鸨东方亚种(Otistardadybowskii)的遗传多样性进行了研究。应用3个大鸨指名亚种的微卫星位点和13个波斑鸨的微卫星位点扩增了47个个体的基因组DNA,筛选出8个具有多态性的微卫星。其中有3个微卫星的多态性较低,其余5个微卫星的多态性较高。各位点的观察杂合度为0.0435-1.0000,平均杂合度(h)为0.6595;各位点多态信息含量(PIC)为0.0416-0.8520,平均为0.5497;有效等位基因数(E)为1.04-7.46,平均为3.61。4个位点符合HardyWeinberg平衡,4个位点偏离了HardyWeinberg平衡。多方面比较发现,大鸨东方亚种遗传多样性很低,且低于指名亚种,这可能由于其种群较小、历史遗传瓶颈作用、生境破碎化、分布地域紧缩等原因造成的。     

A panel of 20 highly variable microsatellite polymorphisms in rhesus macaques (Macaca mulatta) selected for pedigree or population genetic analysis

This paper reports 20 new microsatellite loci that are highly polymorphic in rhesus macaques (Macaca mulatta). We screened known human microsatellite loci to identify markers that are polymorphic in rhesus macaques, and then selected specific loci that show substantial levels of heterozygosity and robust, reliable amplification. The 20 loci reported here were chosen to include one highly informative microsatellite from each rhesus monkey autosomal chromosome. Fourteen of the 20 polymorphisms are tetranucleotide repeats, and all can be analyzed using standard PCR and electrophoresis procedures. These new rhesus markers have an average of 15.5 alleles per locus and average heterozygosity of 0.83. This panel of DNA polymorphisms will be useful for a variety of different genetic analyses, including pedigree testing, paternity analysis, and population genetic studies. Many of these loci are also likely to be informative in other closely related Old World monkey species.     

Designing new microsatellite markers for linkage and population genetic analyses in rhesus macaques and other nonhuman primates

Identification of polymorphic microsatellite loci in nonhuman primates is useful for various biomedical and evolutionary studies of these species. Prior methods for identifying microsatellites in nonhuman primates are inefficient. We describe a new strategy for marker development that uses the available whole genome sequence for rhesus macaques. Fifty-four novel rhesus-derived microsatellites were genotyped in large pedigrees of rhesus monkeys. Linkage analysis was used to place 51 of these loci into the existing rhesus linkage map. In addition, we find that microsatellites identified this way are polymorphic in other Old World monkeys such as baboons. This approach to marker development is more efficient than previous methods and produces polymorphisms with known locations in the rhesus genome assembly. Finally, we propose a nomenclature system that can be used for rhesus-derived microsatellites genotyped in any species or for novel loci derived from the genome sequence of any nonhuman primate.     

A microsatellite marker for studying the ecology and diversity of fungal endophytes (Epichloë spp.) in grasses.

Randomly amplified polymorphic DNA fingerprinting, which is based on PCR with arbitrary 10-nucleotide primers, were used to analyze genetic diversity among isolates of the endophytic ascomycete Epichloë typhina, which were collected at a single field site from a population of one of its hosts, the grass Bromus erectus. One of the polymorphic randomly amplified polymorphic DNA PCR products occurred in all isolates as single bands with different but closely related sizes. Two of the size variants of this product were cloned and sequenced, and they were found to represent the same DNA sequence, except for a stretch of tandem repeats of the trinucleotide AAG.TTC, which differed in size, consisting of 8 and 18 repeats, respectively. Tandem repeats of this type are called microsatellites. Oligonucleotides were synthesized corresponding to portions of the sequence flanking the microsatellite and were used for PCR amplification of the loci from the genomic DNAs of different Epichloë isolates. A single PCR product was found for most isolates, indicating that the sequence represented a single genetic locus. Five alleles that could clearly be distinguished in size were found in a population of 91 field isolates. PCR with (AAC)8 and (AAG)8 as primers yielded a number of amplified bands from genomic DNA of Epichloë isolates, indicating that these types of microsatellites occur frequently in the genome of this fungus. A survey of all fungal DNA sequences currently deposited in the DNA sequence databases of EMBL and GenBank revealed that microsatellites of different repeating units are widespread in fungi.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characteristics of single- and multi-copy microsatellites from Pinus radiata

 Dinucleotide microsatellites were isolated from Pinus radiata using both a standard genomic library and libraries enriched for microsatellites. Locus-specific primers were designed to amplify 43 unique microsatellites. Thirty two of these loci had interpretable PCR patterns, 11 of which were polymorphic in a screen of 19 P. radiata individuals; all 11 polymorphic loci contained at least 17 repeats in the sequenced plasmid. Six of the eleven primer pairs amplified multiple fragments per individual (3–8), suggesting that these loci were present in multiple copies in the genome. Genotyping a 48-tree P. radiata production population with seven of the most polymorphic microsatellites revealed an average of 17 bands per locus (the multi-copy microsatellites were treated as one locus). When tested on known pedigrees, both single and multi-copy microsatellites exhibited co-dominant inheritance and Mendelian segregation. Two loci had null alleles and one locus had a high frequency of non-parental alleles, suggesting a high mutation rate. Eight of these microsatellites, including five multi-copy loci, were placed on a partially constructed P. radiata genetic map. Four of the five multi-copy microsatellites had two or more sets of alleles that mapped to the same locus, and the fifth mapped to two unlinked loci. All seven tested primer pairs amplified PCR products from other species of hard pine, three amplified products from soft-pine species, and one amplified bands in other conifers. Received: 10 November 1997 / Accepted: 5 January 1998     

Comparative Assessment of Genetic Variability in the Populations of Endemic and Endangered Yellow Catfish, Horabagrus brachysoma (Teleostei: Horabagridae), Based on Allozyme, RAPD, and Microsatellite Markers

The comparative assessment of genetic diversity using allozymes, random amplified polymorphic DNA (RAPD), and microsatellite markers was conducted in endemic and endangered yellow catfish (Horabagrus brachysoma) sampled from three locations in Western Ghats river systems of India. Among the three markers, microsatellites show more polymorphism, having 100% polymorphic loci, whereas allozymes show the least (56%). In RAPD, 60.5% of fragments were polymorphic. Observed heterozygosity and F(ST) values were very high in microsatellites, compared with the other markers. Microsatellite and RAPD markers reported a higher degree of genetic differentiation than allozymes among the populations depicted by pairwise F(ST)/G(ST), AMOVA, Nei's genetic distance, and UPGMA dendrogram. The three classes of markers demonstrated striking genetic differentiation between pairs of H. brachysoma populations. The data emphasize the need for fishery management, conservation, and rehabilitation of this species.     

Characterization of equine microsatellites and microsatellite-linked repetitive elements (eMLREs) by efficient cloning and genotyping methods.

We performed efficient cloning and genotyping methods for isolation of a large number of polymorphic microsatellites. The methods contain the time-efficient cloning method of constructing microsatellite-enriched libraries and the economic genotyping method of fluorescent labeling of PCR products. Eighty novel equine microsatellites cloned were efficiently isolated from the enrichment library and analyzed for genotype polymorphism. Of these, 72 microsatellites were analyzed with a good resolution. The average heterozygosity of all loci was 0.52, and the number of alleles ranged from one to 9 with an average of 4.5 alleles. The other eight loci showed multiple bands of PCR products, suggesting the occurrence of microsatellites in a repetitive element, in which the number of microsatellite repeats varies among different members of the repetitive element. We found five homologous groups at flanking regions in comparison with the flanking regions of microsatellites from DNA databases. One of them showed homology to equine repetitive element-2. In the other four homologous groups, the two groups were named equine microsatellite-linked repetitive element-1 (eMLRE-1) and equine microsatellite-linked repetitive element-2 (eMLRE-2) as novel equine repetitive elements identified from equine genome. These data should help the analysis of equine DNA sequences and the design of equine genome markers.     

Isolation and characterization of microsatellite loci in Ononis repens,Leguminosae

Ten polymorphic microsatellites were isolated from Ononis repens, using a microsatellite enrichment protocol and selective hybridization with a mixed synthetic dinucleotide repeat probe. Primers for DNA amplifications using polymerase chain reaction (PCR) were designed and synthesized. The loci amplified in both O. repens and O. spinosa. All 10 loci were polymorphic in each of four populations studied. These microsatellite markers will be useful for population genetic analysis and biodiversity studies of O. repens and O. spinosa.     

Isolation and characterization of microsatellite loci in the Caribbean gorgonian Pseudopterogorgia elisabethae

We report on the isolation and characterization of five polymorphic microsatellites in the gorgonian Pseudopterogorgia elisabethae from genomic DNA‐enriched libraries. Forty‐four microsatellites were screened from the libraries with the oligonucleotide probe (CA)₁₂. Five of the screened microsatellites were polymorphic. The levels of polymorphism found in 50 genotyped individuals from a single population suggest that microsatellites are useful tools for the study of genetic variation in gorgonians. These are the first microsatellite loci reported from any gorgonian species.