版纳小耳猪近交系5家系35个微卫星座位的遗传分析

利用35个微卫星座位对版纳小耳猪近交系5个家系进行了遗传检测。统计各家系的等位基因组成,计算各家系的平均基因纯合率,利用基因频率计算出各家系的平均杂合度及品系间的遗传距离,并进行系统聚类。结果表明各家系的平均基因纯合度均较高,其151家系达到88.79％;PIC（多态信息含量）和平均杂合度均较普通商品猪低;各家系等位基因组成差别较大;各家系间亲缘关系与其近交过程一致,据此认为版纳小耳猪近交系5家系均具有较高的近交程度;其基因多态性和遗传多样性较普通商品猪低;各家系均已构成独立遗传群体。     

海南五指山猪遗传多样性的微卫星分析

海南五指山猪(Wuzhishan pig)是我国珍稀的小型猪品种。它的解剖学、生理学、疾病发生机理等都与人类极其相似,具有重要的应用价值,可用于心血管病、皮肤烧伤和新药评价等许多方面的研究。作者利用多重PCR和基因扫描技术对五指山猪32个微卫星基因座进行了遗传检测。统计了全群、核心群和近交群的等位基因组成,并计算了它们的平均纯合率、多态信息含量(PIC)和平均杂合度。结果显示,全群、核心群和近交群32个基因座的平均等位基因数分别为14.590个、9.410个、13.660个,平均基因纯合率分别为44%、44.3%、44%,平均PIC分别为0.742、0.708、0.731,平均杂合度分别为0.560、0.558、0.559。这表明海南五指山猪虽然遗传基础比较稳定,但仍具有较大的遗传变异。上述结果对于海南五指山猪的保种、定向选育、开发利用都具有重要的指导意义。     

贵州小型香猪和广西巴马小型猪微卫星位点的遗传学分析

利用35个微卫星位点对贵州小型香猪,广西巴马小型猪的封闭群进行了遗传检测,计算出两个小型猪品系个体样本微卫星位点的平均杂合度,多态信息含量（PIC）、有效等效基因数及品系间的遗传距离。结果表明两个品系的小型猪平均杂合度和PIC均较低,有效等效基因数与实测等位基因数较接近,也表明两品系均有稳定的遗传;两者的遗传距离表明贵州小型香猪和广西巴马小型猪亲缘关系较近,同时表明两者已分别成为两个猛增的封闭群动物。     

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。     

五个家系吉富罗非鱼的遗传多样性分析

吉富罗非鱼是用家系选育方法获得的优良品系.该方法可避免近亲交配引起的衰退.从罗非鱼的第二代遗传图谱上选取10个微卫星标记,对吉富罗非鱼5个家系共121尾鱼进行遗传多样性分析.结果表明:各位点的等位基因数为2～6个,平均等位基因数为4;有效等位基因数1.3920～3.6689,平均有效等位基因数为2.4733;平均杂合度观测值0.5984,平均杂合度期望值0.5642.5个家系的多态信息含量从小到大以依次为22家系、25家系、59家系、49家系、31家系,均为中度多态性.家系间基因分化系数(GST)为0.1676,各家系之间存在一定遗传分化.根据遗传距离采用UPGMA法对5个家系进行聚类,49家系和59家系遗传距离最小聚为一类, 它们与31家系遗传距离最远.对10个微卫星位点的基因型进行分析,结果发现在GM578位点,22家系呈其他几个家系没有的BB基因型,有望成为22家系的标记.     

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。     

鳜原种群体和养殖群体遗传多样性的微卫星分析

本研究利用20对微卫星引物对鳜(Siniperca chuatsi)原种群体和养殖群体进行遗传多样性分析。结果表明,在鳜原种群体中检测到多态性位点14个,养殖群体11个。在两个群体中共检测到等位基因数96个,其中原种群体检测到等位基因数53个,每个位点的等位基因数在1～7之间,平均有效等位基因数为2.7390;养殖群体检测到等位基因数43个,每个位点的等位基因数在1～6之间,平均有效等位基因数为2.1284。原种群体的平均观察杂合度0.5708,Nei氏期望杂合度0.5295,平均多态信息含量PIC0.5353;养殖群体的平均观察杂合度0.3839,Nei氏期望杂合度0.4011,平均多态信息含量PIC0.5043。因此,与养殖群体相比,鳜原种群体仍有丰富的遗传多样性。本研究可为鳜种质资源的保护、监测和遗传育种提供分子水平上的数据。     

不同猪种IGFBP3基因内含子2、3多态性分析

本研究采用PCR-SSCP技术结合DNA直接测序对滇南小耳猪、大白猪、梅山猪、香猪、海南五指山猪封闭群、近交系、海南黑猪系(临高猪,屯昌猪)等8个猪种的IGFBP3基因内含子1、2、3的SNP多态性进行检测,并分析其与五指山猪3个生长阶段体质量的关联性。结果表明:内含子2、3的PCR片断表现有多态性,且出现3种基因型。随后的测序结果表明,它们都在相应的区域存在着SNP变异;内含子3在地方猪种大多表现BB基因型和以B等位基因为主,尤其是小型猪;内含子2在中外不同猪种的基因型频率和等位基因的频率分布则不存在品种的特异性,在地方猪种和外来猪种的分布规律不明显。群体遗传多态性检测显示8个猪种在这2个位点均处于中度多态(0.25PIC0.5);关联分析显示五指山猪IGFBP-3内含子3 AA基因型和内含子2 DD基因型猪在8月龄、12月龄的生长体重分别与AB、BB基因型和CC、CD基因型个体存在显著性差异(p0.05),但在2月龄时没有此规律。     

虹鳟6个养殖群体遗传多样性的微卫星分析

利用14对微卫星分子标记对虹鳟的6个养殖群体进行遗传多样性分析。结果表明：6个群体的平均等位基因数A为 2.89～4.22,平均有效等位基因数Ne 为2.15～2.78,平均观察杂合度Ho 为0.4801～0.6786,平均期望杂合度He 为0.5052～0.6211,平均多态信息含量PIC 为0.4298～0.5762;其中渤海站群体的等位基因数最多、多态信息含量最高,有效种群最大,通过基因型的P值发现6个群体只在位点AF375034符合Hardy-Weinberg平衡,在其他位点都不同程度的偏离平衡,同时对6个群体的遗传距离进行了估算,聚类分析发现挪威群体与其他群体遗传距离最远。     

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。     

The phylogeny of Chinese indigenous pig breeds inferred from microsatellite markers

A genetic study of 32 local Chinese, three foreign pig breeds [Duroc (DU), Landrace and Yorkshire], and two types of wild boar (Hainan and Dongbei wild boar) based on 34 microsatellite loci was carried out to clarify the phylogeny of Chinese indigenous pig breeds. The allele frequencies, effective numbers of alleles, and the average heterozygosity within populations were calculated. The results showed that the genetic variability of the Lingao pig was the largest, while the Jiaxing pig was the lowest. The greatest distance between domestic pigs was found between Shanggao and DU pig and the shortest was found between Wuzhishan and Lingao pig, respectively. A neighbour-joining tree constructed from Modified Cavalli-Sforza genetic distances divided Chinese pigs into two clusters; four subclusters were also identified. Our results only partly agree with the traditional types of classification and also provide a new relationship among Chinese local pig breeds. Our data also confirmed that Chinese pig breeds have a different origin from European/American breeds and can be utilized in programmes that aim to maintain Chinese indigenous pig breeds.     

三品系小型猪35个微卫星基因座的遗传学研究

利用35个微卫星基因座对中国三个品系的小型猪（贵州小型香猪、广西巴马小型猪、版纳小耳猪近交系）进行了遗传检测。计算出三个小型猪品系个体样本在35个微卫星基因座的纯合率,并对其进行t检验。计算出各品系的平均杂合度,多态信息含量（PIC）及品系间的遗传距离,并进行了系统聚类。结果表明三个品系的小型猪其基因纯合率均较高,其中版纳小耳猪近交系的基因纯合率最高;PIC和平均杂合度均较低;贵州小型香猪和广西巴马小型猪亲缘关系较近,并均与版纳小耳猪近交系的亲缘关系略远。 Abstract：The polymorphism of 35 microsatellites in the three miniature pig breeds in China(Guizhou miniature pig, Guangxi Bama miniature pig, Banna miniature pig inbred) was analysed. Rates of homozygote for 35 microsatellite loci in three miniature pig breeds were calculated,and t-test for them were performed. Mean heterozygosity and polymorphism information content(PIC) were calculated for all breeds, and genetic distances between these breeds were estimated. The dendrograms were obtained based on genetic distances. The results suggest that rates of homozygote in the three breeds are all high, and that is the highest in Banna miniature pig inbred. The results also suggest that polymorphism information content and mean heterozygosity in all the three breeds are low, and the genetic relationship between Guizhou miniature pig and Guangxi Bama miniature pig is closer than their relationship with Banna miniature pig inbred.     

中外11个猪种A-FABP基因微卫星遗传变异的研究

利用微卫星技术对五指山猪、沂蒙黑猪、汉江黑猪、莱芜猪、北京黑猪、民猪、成华猪、内江猪、二花脸猪、巴马香猪和大白猪11个猪种共420头猪的脂肪细胞脂肪酸结合蛋白基因内含子的微卫星序列的遗传变异进行了研究。研究表明：（1）中国猪种在A-FABP基因微卫星基因座上有极高的的多态性,五指山猪的PIC最高（PIC=0.7904）并检测到11个等位基因,但北京黑猪仅检测到两个等位基因。（2）本实验中,只有北京黑猪、民猪、巴马香猪和大白猪A-FABP基因微卫星在群体中的分布达到平衡状态。（3）群体间的基因分化系数分析表明,中国猪种在该微卫星基因座上分化程度平均约为40.83%。Abstract：The genetic variations of microsatellites in intron 2 of the porcine adipocyte fatty acid-binding protein (A-FABP) genes were investigated in 420 pigs including Wuzhishan pig,Yimeng black pig,Hanjiang black pig,Laiwu pig,Beijing black pig,Min pig,Chenghua pig,Neijiang pig,Erhualian pig,Bama xiang pig and Large White pig.The results suggested as follows：（i）PIC of the Wuzhishan pig breed is the highest（0.7904） and 11 alleles were detected. Compared with Large White pig,Chinese pig breeds showed a great polymorphism of A-FABP microsatellites except Beijing black pig in which only 2 alleles were detected.（ii）Only Min pig, Bama xiang pig, Beijing black pig and Large White pig were in Hardy-Weinberg equilibrium. （iii）The analysis of genetic differentiation showed that the average value of the A-FABP gene differentiation of 10 Chinese pigs is about 40.83%.     

Temporal changes in genetic variation of north European cattle breeds

Temporal changes in genetic variation within and between 13 North European cattle breeds were evaluated using erythrocyte antigen systems and transferrin protein as genetic markers. Current data on allele frequency distributions of markers in large commercial and smaller endangered native cattle breeds were compared to data published during 1956 to 1975. Intrabreed genetic variation was quantified by conventional parameters (e.g. heterozygosity, average number of alleles per locus) and migration by the effective migration rate. The neighbour-joining dendrogram of relationships between old and present cattle populations was constructed using Nei's standard genetic distance. Variance effective population size was estimated from changes in allele frequencies over time. Comparison of old and new data indicated some significant changes in allele frequencies. In six of the breeds, a few low-frequency alleles in the old data were absent in the present samples. Heterozygosity remained stable in most breeds. The harmonic means for variance effective population size ranged between 30 and 257. Current results indicate that despite marked declines in total population sizes, North European native cattle breeds have retained a reasonably high genetic diversity. However, their genes contribute less than previously to genetic variation of Nordic production breeds. Commercial breeds do not appear to have a larger effective population size than native breeds. The present effective population sizes imply that Nordic breeds could have lost from 1 to 11% of their heterozygosity over a 20-40-year period.     

红壳色文蛤F1代养殖群体多样性分析

运用形态学标记和分子标记对江苏省文蛤良种场红壳色文蛤F1代养殖群体(父母本为江苏野生红壳色群体)进行遗传多样性分析。用文蛤壳长、壳宽、壳高和体重4个可量性状进行形态学数据的聚类分析,显示可量性状变异系数在38.48%-82.95%。运用7个引物微卫星基因座的多态性进行了养殖群体F1代的分子标记评估,结果表明,7个微卫星基因位点的平均等位基因数3.857 1,平均有效等位基因数2.583 0,平均观察杂合度0.565 3,平均期望杂合度0.565 3,Shannon指数平均数1.050 1,多态信息含量平均数0.522 5。综合形态学数据和分子标记的研究结果表明,红壳色文蛤江苏养殖群体F1代的遗传多样性处于中度偏高水平,具有较高的遗传改良潜力。     

湖北省三品种猪27个微卫星座位的遗传变异

采用国际动物遗传学会（ISAG）和联合国粮农组织（FAO）共同推荐的27个微卫星标记,对湖北省3个主要地方猪种（通城猪、清平猪和阳新猪）的遗传变异进行了检测。计算出各个品种的基因杂合度、各个座位的多态信息含量及品种间的遗传距离。结果表明,3个地方猪种的平均基因杂合度分别为0.7489、0.6987和0.6273,遗传多样性比较丰富;通城猪和清平猪亲缘关系较近,而两者与阳新猪亲缘关系略远。     

Genetic Diversity of Yunnan Local Pig Breeds Inferred from Blood Protein Electrophoresis

Protein electrophoresis was used to examine theblood protein polymorphism in Yunnan local pig breeds,i.e., the Saba pig, Dahe pig, and Diannan small-ear pigbreeds. Of 38 genetic loci surveyed, 9 were found to be polymorphic. The percentage ofpolymorphic loci (P) varies from 0.1875 to 0.2121, andthe mean individual heterozygosity (H) varies from0.0712 to 0.1027 in three pig breeds. The resultsindicate that blood protein polymorphism in Yunnan pigbreeds is high. Yunnan local pig breeds have a wealth ofgenetic diversity at the level of blood proteins.     

Genomic Diversity in Pig (Sus scrofa) and its Comparison with Human and other Livestock

We have reviewed the current pig (Sus scrofa) genomic diversity within and between sites and compared them with human and other livestock. The current Porcine 60K single nucleotide polymorphism (SNP) panel has an average SNP distance in a range of 30 - 40 kb. Most of genetic variation was distributed within populations, and only a small proportion of them existed between populations. The average heterozygosity was lower in pig than in human and other livestock. Genetic inbreeding coefficient (F(IS)), population differentiation (F(ST)), and Nei's genetic distance between populations were much larger in pig than in human and other livestock. Higher average genetic distance existed between European and Asian populations than between European or between Asian populations. Asian breeds harboured much larger variability and higher average heterozygosity than European breeds. The samples of wild boar that have been analyzed displayed more extensive genetic variation than domestic breeds. The average linkage disequilibrium (LD) in improved pig breeds extended to 1 - 3 cM, much larger than that in human (~ 30 kb) and cattle (~ 100 kb), but smaller than that in sheep (~ 10 cM). European breeds showed greater LD that decayed more slowly than Asian breeds. We briefly discuss some processes for maintaining genomic diversity in pig, including migration, introgression, selection, and drift. We conclude that, due to the long time of domestication, the pig possesses lower heterozygosity, higher F(IS), and larger LD compared with human and cattle. This implies that a smaller effective population size and less informative markers are needed in pig for genome wide association studies.