长江中上游两个鲢群体遗传变异的微卫星分析

对长江中上游2个鲢群体使用39个微卫星标记进行了遗传多样性分析, 计算并统计了平均观测等位基因数、平均有效等位基因数、多态信息含量、遗传杂合度、Hardy-Weinberg平衡偏离指数、遗传相似系数、遗传距离等遗传参数。结果表明: 万州鲢和监利鲢群体所检测微卫星位点的平均观测等位基因数分别为6.128和4.974; 平均有效等位基因数分别为4.107和3.395; 多态位点百分率分别为100和94.87; 39个微卫星标记共有等位基因259个, 173个等位基因为两群体所共有; 多态微卫星位点的PIC在0.077~0.865之间变动,平均为0.617; 两群体所检测位点平均观测杂合度为0.834和0.775, 平均期望杂合度为0.713和0.623; 两个群体间的遗传相似系数为0.618, 群体间的遗传距离为0.482。结果显示长江中上游两个鲢群体间存在显著遗传分化, 应隶属于不同的种群。     

微卫星标记对中国引进加州鲈养殖群体遗传多样性的分析

为了解我国引进加州鲈养殖群体的种群遗传结构和种质资源现状,本文发展了加州鲈的微卫星标记。用磁珠富集法获得加州鲈微卫星标记267个,设计并合成了85对微卫星引物对加州鲈的基因组进行遗传多样性分析,从中筛选出18对并从网上查询获得3对共21对引物对加州鲈的基因组DNA进行扩增。PCR扩增产物在8%的聚丙烯酰胺凝胶中分离,硝酸银染色,经紫外成像后对电泳条带进行统计分析。计算得到三个群体的平均等位基因数分别为2.3、2.3和2.1;多态信息含量（PIC）为0.0906—0.7480;平均杂合度观测值分别为0.384、0.396和0.356;杂合度期望值为0.375、0.403和0.368。统计结果初步表明3个不同群体平均杂合度处于中等偏低水平,遗传多样性不高。     

利用17个微卫星标记分析鳙鱼的遗传多样性

选用本实验室克隆的17个鳙鱼微卫星分子标记分析四川泸州和江西鄱阳湖的两个种群鳙鱼的遗传多样性及种质特性,计算和统计了杂合度、多态信息含量（PIC）、有效等位基因数、等位基因频率、遗传距离、遗传相似系数、Hardy-Weinberg平衡偏离指数等方面内容。结果表明：选择使用17个微卫星标记,其中有4个为单态标记,13个为多态标记。江西和四川鳙鱼群体每个微卫星位点的平均等位基因数分别为3.325及3.882,平均有效等位基因数分别为3.531及2.676,多态位点百分率分别为82.4及70.5, 17个微卫星标记共有等位基因71个,多态微卫星位点的PIC在0.114~0.960之间变动,平均为0.417 ,两群体位点平均观测杂合度为0.385和0.452,平均期望杂合度为0.360和0.422,两个群体间的遗传相似系数为0.897,群体间的遗传距离为0.109。     

滩羊微卫星标记多态性及与体尺性状关联分析

滩羊是我国特有的蒙古羊品种,肉质鲜美但生长缓慢。通过筛选的29个高多态性微卫星标记,对宁夏盐池滩羊种羊场基础母羊群体用随机抽样法检测了96个成年个体,测量了体重和体尺数据,分析了其微卫星标记遗传多样性、群体遗传结构及分子标记与表型的相关关系。结果显示,微卫星标记平均等位基因数9.5,平均有效等位基因数4.5,平均期望杂合度0.72,平均观测杂合度0.64,平均多态信息含量0.69;滩羊基础母羊群体保持了丰富的遗传多样性;关联分析结果显示MAF33与滩羊的体高、胸深显著相关,BMS1788与荐高、胸围显著相关,而BL41、BMS835、BOVILS56、MAF33和BMS500与管围极显著关联。这些标记对未来滩羊的分子辅助育种有所帮助。     

草鱼种群SSR分析中样本量及标记数量对遗传多度的影响

利用45对微卫星分子标记（SSR）,以草鱼(Ctenopharyngodon idellus)自然群体为实验材料,探讨野生群体遗传多样性研究中所需的最适样本量与标记量。实验设置6个样本量梯度,9个标记量梯度。对等位基因数（Na）、有效等位基因数（Ne）、观察杂合度（Ho）、期望杂合度（He）等遗传多样性指标的变化趋势进行统计分析。结果表明,样本量、微卫星标记的数量和多态性水平对群体遗传多样性均有较大的影响,其中等位基因数与样本量大小呈显著正相关,而杂合度随标记量的增多而剧烈波动。当取样量大于40,标记量大于25时,各遗传参数值趋于稳定。因此,在应用微卫星标记对水产动物自然群体的遗传学研究中,要根据所研究种类的特点,尽可能采样40尾以上,采用25个以上标记,避免由人为选择的偏差对群体遗传多样性水平的正确评估所造成的影响。同时根据上述研究结果,对陕西草鱼自然群体进行了遗传多样性的评估,结果显示该群体平均等位基因数（MNA）、平均有效等位基因数、平均观测杂合度、平均期望杂合度分别为7.26、4.21、0.73、0.68,认为该群体具有较高的遗传多样性。     

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。     

三个野生群体日本囊对虾遗传多样性的SSR分析

为了解野生种群日本囊对虾遗传分化和改良遗传育种,用SSR技术对福建厦门(XM)、广东湛江(ZJ)、广西北海(BH)3个地区野生日本囊对虾进行遗传多样性的研究。采用了10对微卫星引物对3个野生种群进行分析,10个微卫星位点在3个种群中均表现为高度的多态性,每个位点平均检测到3.87个等位基因;平均多态信息含量为0.5893;3个群体的观测杂合度分别为0.6243、0.5704、0.4661,全部群体观测杂合度平均为0.5536;期望杂合度分别为0.7193、0.6189、0.6226,全部群体平均期望杂合度为0.6536。这说明3个野生种群在10个微卫星位点上均具有丰富的遗传多样性。基于Nei's遗传距离的聚类分析显示厦门群体和湛江群体的遗传距离较近。     

利用微卫星技术分析不同类群鸡的遗传多样性

利用8个微卫星标记分析了6个生产类群鸡的遗传多样性。计算了各群体在各位点上的等位基因频率,并据此计算出各群体的平均遗传杂合度(h)、多态信息含量(PIC)和有效等位基因数(Ne)。结果表明:6个鸡群在8个微卫星座位上的基因频率存在明显的差异,其平均基因杂合度为0.7317,平均多态信息含量为0.6815。其中,群体平均杂合度最高的是安卡红鸡,为0.7716;平均杂合度最低的是新罗曼鸡,为0.7073。所选的8个微卫星座位均为高度多态,可作为有效的遗传标记用于鸡群体遗传多样性的分析。     

中国圈养林麝微卫星DNA多样性研究

本文利用13对微卫星标记,对我国3个核心种源地（巴山、秦岭、川西高原）圈养林麝种群进行遗传多样性和遗传结构分析。在167份样品中共检测到142个等位基因（Na）,每个位点等位基因数介于7~16,均值为10.92,平均有效等位基因数（Ne）为6.3730,期望杂合度（He）和观测杂合度（Ho）均值分别为0.8302和0.3897。这些圈养林麝种群遗传多样性水平较高,但较低的观测杂合度表明圈养群体存在近交现象。两两群体间的Fst 值和AMOVA分析结果均表明种群之间分化程度不明显。群体遗传结构分析显示,全部样本聚为3个遗传簇（最佳K值=3）,其主体与3个地理来源相符,但种群间存在基因渗透现象。本研究中的秦岭种群遗传变异最为丰富,可以作为种质改良的基因池。     

太平洋牡蛎养殖与野生群体遗传变异的微卫星研究

应用微卫星标记技术研究5个中国太平洋牡蛎养殖群体和2个日本太平洋牡蛎野生群体的遗传变异。研究中所使用的7个微卫星位点在养殖和野生群体中都显示出了高多态性,平均等位基因数为19.1～29.9,平均期待杂合度为0.916～0.958。养殖群体和野生群体的平均等位基因丰度及观察杂合度没有显著性差异。遗传分化系数及等位基因杂合度分析显示所有的群体间都有显著性差异。构建的NJ树中,7个群体聚为3支,养殖群体和野生群体可以清楚地分开,在养殖群体中又分为南北两支。分配检验中,97%～100%的正确率证明了微卫星标记在群体识别分析中的可行性。本研究结果对太平洋牡蛎管理模式的设计和选择育种具有重要意义。     

广西本地鲢和长丰鲢群体遗传多样性分析

本研究采用32个微卫星标记分析广西本地鲢和长丰鲢两个群体的遗传差异,计算并统计其微卫星遗传参数。结果显示:32个微卫星标记广西本地鲢鱼和长丰鲢群体共检测到等位基因119个,其中两群体所共有为88个;平均观测等位基因数为2.937 5和3.406 2;平均有效等位基因数为1.787 3和2.074 7;多态信息含量(PIC)在0～0.727 1和0～0.748 4之间,平均值为0.293 6和0.360 0,表明两个群体的遗传多样性均不高。两群体平均观测杂合度为0.373 9和0.559 7,平均期望杂合度为0.327 1和0.413 3,均表现为本地鲢群体低于长丰鲢群体,说明两个群体的均不高,并且广西本地鲢群体的遗传多样性低于长丰鲢群体;两个鲢鱼群体间的遗传距离和遗传相似系数分别为0.297 7和0.742 5,表明两个鲢鱼群体间的遗传差异不大。两个群体的遗传分化系数(Fst)在不同微卫星位点间差异明显,平均0.171 7。本研究为广西地方鱼类种质资源保护和利用提供了理论依据。     

New microsatellite markers in chicken optimized for automated fluorescent genotyping

We have isolated and developed 180 new polymorphic chicken microsatellite markers. In addition, primers have been developed for 91 microsatellites derived from the GenBank sequence database (isolated by the laboratory of Terry Burke, Leicester University), of which 89 were polymorphic, and six existing polymorphic markers (HUJ) have been modified. The primer sequences were designed to allow optimal performance of the markers, in sets containing multiple microsatellites, on ABI sequencers. The average number of alleles for the 275 polymorphic markers described was 4·0. Of these markers, 93% were polymorphic in the Wageningen resource population whereas 57% of the markers were polymorphic in the East Lansing reference population and only 44% could be mapped in the Compton reference population. The microsatellite markers described in this paper, in combination with the microsatellite markers published previously, are particularly well suited for performing a total genome scan for the detection of quantitative trait loci (QTL).     

Isolation and characterization of nine polymorphic microsatellite loci in the rock carp, Procypris rabaudi (Tchang)

Nine highly polymorphic microsatellite loci were isolated from AC- and GATA-repeat microsatellite enrichment DNA libraries in the rock carp, Procypris rabaudi (Tchang). The number of alleles for these loci ranged from eight to 18 in tested individuals. Polymorphism information content ranged from 0.712 to 0.908 with an average of 0.837. Average observed and expected heterozygosities were 0.719 and 0.870, respectively. These molecular markers will be useful for the assessment of genetic diversity and analysis of population structure in wild rock carp.     

Microsatellite markers for population studies of the rice blast fungus,Magnaporthe grisea

We developed nine new microsatellite markers for rice blast (Magnaporthe grisea) population studies. These markers were used in addition to nine microsatellite markers previously developed by our group for mapping purpose. Altogether, the 18 markers were used in multiplex PCR (polymerase chain reaction) to characterize six populations from different geographical origins. The average number of alleles per locus across populations ranged from 1.2 to 7 and the total number of alleles detected from 2 to 19. Based on this large range of polymorphism, this set of markers is expected to be useful for different kind of population studies at different geographical scales.     

New polymorphic dinucleotide and trinucleotide microsatellite loci for hop Humulus lupulus L

One hundred and thirty-five microsatellite markers were developed for hop Humulus lupulus L. from di- and trinucleotide-enriched libraries. Seventy-eight primers showed amplification in two tested genotypes. Twenty-four loci were further characterized on a population of 34 hop samples and the number of alleles per locus, observed heterozygosity and expected heterozygosity ranged from two to 20 (9.7 on average), from 0.0294 to 0.9412 (0.6234 on average) and from 0.0294 to 0.9170 (0.6720 on average), respectively. These microsatellite markers will be further used for studying population structures and relationships and for identifying important qualitative and quantitative loci of hop.     

New microsatellite markers for the rare plant Cercidiphyllum japonicum and their utility for Cercidiphyllum magnificum

? Premise of the study: Microsatellite markers were developed for Cercidiphyllum japonicum to study population genetics of this endangered species native to both eastern China and Japan. ? Methods and Results: Using the Fast Isolation by AFLP of Sequences Containing Repeats (FIASCO) protocol, 12 microsatellite markers that were successfully amplified showed polymorphism when tested on 33 individuals from two populations in eastern China and Japan. Overall, the number of alleles per locus ranged between 5 and 18. Eleven markers could be easily amplified and were polymorphic in C. magnificum. ? Conclusions: These results indicate that these microsatellite markers are adequate for detecting and characterizing population genetic structure in Cercidiphyllum at fine and range-wide geographical scales.     

Microsatellite markers for the endangered root holoparasite Dactylanthus taylorii (Balanophoraceae) from 454 pyrosequencing

? Premise of the study: Microsatellite loci were isolated and developed as polymorphic markers for the New Zealand endemic root holoparasite Dactylanthus taylorii for use in population and conservation genetics studies. ? Methods and Results: Shotgun 454 pyrosequencing was performed on genomic DNA pooled from three individuals of D. taylorii. From 61709 individual sequence reads, primers for 753 microsatellite loci were developed in silico and 72 of these were tested for consistent amplification and variability. Ten microsatellite loci were found to be polymorphic and consistently scorable when screened in 44 individuals from five geographically distant populations. The number of alleles per locus ranged from four to 16 with an average of 9.7, and average observed heterozygosity per locus was between 0.182 and 0.634. ? Conclusions: These polymorphic microsatellite markers establish an important resource for ongoing conservation initiatives and planned population genetic studies of D. taylorii.     

Mapping quantitative trait loci for osteochondrosis in fetlock and hock joints and palmar/plantar osseus fragments in fetlock joints of South German Coldblood horses

The aim of this study was to identify quantitative trait loci (QTL) for osteochondrosis (OC) and palmar/plantar osseous fragments (POF) in fetlock joints in a whole-genome scan of 219 South German Coldblood horses. Symptoms of OC and POF were checked by radiography in 117 South German Coldblood horses at a mean age of 17 months. The radiographic examination comprised the fetlock and hock joints of all limbs. The genome scan included 157 polymorphic microsatellite markers. All microsatellite markers were equally spaced over the 31 autosomes and the X chromosome, with an average distance of 17.7 cM and a mean polymorphism information content (PIC) of 63%. Sixteen chromosomes harbouring putative QTL regions were further investigated by genotyping the animals with 93 additional markers. QTL that had chromosome-wide significance by non-parametric Z-means and LOD scores were found on 10 chromosomes. This included seven QTL for fetlock OC and one QTL on ECA18 associated with hock OC and fetlock OC. Significant QTL for POF in fetlock joints were located on equine chromosomes 1, 4, 8, 12 and 18. This genome scan is an important step towards the identification of genes responsible for OC in horses.