Study of polymorphism of satellite DNA of improved and local horse breeds

Interbreed differentiation of 12 improved and local horse breeds is studied based on 17 DNA microsatellites. Genetic differences between breeds are established; private alleles are noted in the majority of breeds. Genetic distances between breeds are calculated, an analysis of which shows considerable genetic differences between local and improved breeds.     

我国地方鸡种遗传多样性研究进展

中国地方鸡种类繁多,研究地方鸡种的遗传多样性,不仅能加强生物多样性的保护,同时对起源、进化、分类鉴定及遗传育种等都有重要意义.分子生物学技术的快速发展为遗传多样性检测提供了更直接、更精确的方法,即直接通过分析DNA水平的序列变化检测动物遗传多样性,DNA分析方法已成为目前最有效的遗传分析方法,避免了根据表型性推断基因型时可能产生的误差.对近3年来中国鸡种在形态学水平、细胞学水平、蛋白质水平、DNA水平上的遗传多样性研究进行综述,为中国优质地方鸡种的培育和选育工作提供参考.     

中国蒙系6个绵羊品种的遗传分化和基因流

利用7对微卫星引物对中国蒙系6个绵羊品种(同羊、小尾寒羊、湖羊、滩羊、乌珠穆沁羊和巴音布鲁克羊)的遗传分化、基因流、遗传分化程度与地理距离间的关系进行分析,并利用遗传距离构建系统树。结果表明:6个绵羊群体中,总群体近交系数Fit最高的位点为OarAE101(0.1670),最低的为MAF33(0.0440);群体间分化系数Fst最高的位点为OarAE101(0.1000),最低的为OarFCB48(0.0220);群体内近交系数Fis最高的位点为OarFCB304(0.0890),最低的为MAF33(0.0050)。Fst平均为3.9%,即由各群体内个体间的差异引起的遗传变异是96.1%,说明遗传变异绝大部分存在于品种内,品种间的遗传分化水平很低。6个绵羊群体每世代两群体间有效迁移个体数为2.7369(滩羊和巴音布鲁克羊)~44.3928(同羊和湖羊),平均为11.2521,均反映出品种间的基因流通畅。品种间的遗传差异与地理距离呈显著相关。初步推断我国蒙系绵羊品种间的遗传分化主要是自然选择(生境异质性)作用的结果。     

Microsatellite characterization of closely related fine-wool sheep breeds

Nine fine-wool sheep breeds from Russia, Kazakhstan, and Azerbaijan are analyzed with respect to 20 microsatellite genes. A high level of heterozygosity for each locus is shown. A low level of interbreed differentiation (θ = 1.9%) is established. A complex origin of the investigated Merino sheep breeds is shown genetically.     

Molecular genetic analysis of heterogeneity of rainbow trout breeds

The genetic diversity of three rainbow trout breeds—Amber Wild Color, Kamloops, and Donaldson—are studied by the RAPD-PCR method. Fragments characteristic for individual trout species are found among polymorphic DNA fragments with a different frequency. A high level of similarity between Amber Wild Color and Kamloops breed and low level between Amber Wild Color and Donaldson trout breeds is shown.     

Genome-wide detection for runs of homozygosity analysis in three pig breeds from Chinese Taihu Basin and Landrace pigs by SLAF-seq data

Erhualian (E), Meishan (MS) and Mi (MI) pigs are excellent indigenous pig breeds in Chinese Taihu Basin, which have made great contributions to the genetic improvement of commercial pigs. Investigation of the genetic structure and inbreeding level of the 3 pig breeds is of great significance for the sustainable breeding of commercial pigs. The length and number of runs of homozygosity (ROH) as well as the frequency of genomes covered by ROH can be used as indicators to evaluate the level of inbreeding and the origin of the population. In this study, the ROH characteristics of E, MS, MI and Landrace (L) pigs were analyzed by SLAF-seq data, and the inbreeding coefficient based on ROH (F_ROH) was calculated. In addition, we have identified candidate genes in the genomic regions associated with ROH. A total of 10568 ROH were detected in 116 individuals of 4 pig breeds. The analysis showed that there were significant differences in genetic structure between 3 Taihu Basin pig breeds and L, and the genetic structure of E and MI was similar. The results of F_ROH showed that the inbreeding level of MS was the highest (0.25±0.07), while E and MI were lower than L. Compared with the other 3 pig populations, MS showed a higher frequency of long ROH (>5 Mb), indicating higher inbreeding in MS in recent generations. A large number of candidate genes related to reproductive traits are located in the genomic regions with a high frequency of ROH, and these genes are expected to be used as candidate genes in marker-assisted selection (MAS) breeding programs. Our findings can provide theoretical support for genetic conservation and genetic improvement of 3 pig breeds in Chinese Taihu Basin.     

Genetic structure of the purebred domestic dog

We used molecular markers to study genetic relationships in a diverse collection of 85 domestic dog breeds. Differences among breeds accounted for approximately 30% of genetic variation. Microsatellite genotypes were used to correctly assign 99% of individual dogs to breeds. Phylogenetic analysis separated several breeds with ancient origins from the remaining breeds with modern European origins. We identified four genetic clusters, which predominantly contained breeds with similar geographic origin, morphology, or role in human activities. These results provide a genetic classification of dog breeds and will aid studies of the genetics of phenotypic breed differences.     

Study on Dynamic Information of Animal Genetic Resources in China

The dynamic information of 331 animal genetic resources in 17 important animal genetic re-source provinces (regions) was analyzed. According to the population inbreeding coefficient, combiningwith the information of population dynamic change trend and cross degree, these genetic resources forthreatened degrees were classified. The results indicated that the population size of 138 breeds had in-creased, 147 breeds had decreased, 3 breeds were constant, 7 breeds (or varieties) were extinct, 9 breeds(or varieties) were critically endangered and needed urgently conserve, 50 breeds (or varieties) were endan-gered and should be conserved. We put forward a conservation and utilization plan for animal genetic re-sources.     

应用微卫星DNA标记进行边鸡群体遗传多样性分析

目前,微卫星DNA标记已被广泛应用于动物遗传育种研究中,可有效地进行群体遗传多样性分析,并可估算群体间的遗传距离。为了从分子水平上揭示边鸡群体的遗传结构及系统地位,利用鸡基因组中均位于常染色体上的5个微卫星DNA标记,检测了边鸡群体的遗传多样性,并以大骨鸡做了比较分析;同时,初步探讨了边鸡在国内几个地方鸡种中的系统地位。结果表明,5个微卫星位点共检测到38个等位基因,其中ADL0146位点的等位基因数最少(5个),而ADL0136和ADL0185两个位点的等位基因数最多(9个),平均等位基因数为7.6个.边鸡群体在5个微卫星位点的平均多态信息含量、平均基因杂合度(h)和平均有效等位基因数(Ne)分别为0.667 1、0.745 7和4.044 3,边鸡群体内比大骨鸡群体有更丰富的遗传多样性;聚类分析结果显示,边鸡与大骨鸡亲缘关系最近,而与鲁西斗鸡亲缘关系相对较远。该系统聚类结果与这些地方鸡种的系统分化与选育历史是基本一致的。     

9个山羊品种微卫星DNA遗传多样性分析

为了研究湘东黑山羊、川东白山羊、云岭山羊、板角山羊、黄淮山羊、圭山山羊、贵州白山羊、安徽白山羊和波尔山羊9个山羊品种的遗传多样性,利用微卫星标记技术检测了4个微卫星座位（OarAE101、OarHH55、BM1329、BM143）的多态性。结果表明,9个山羊品种的4个微卫星座位中共检测到53个等位基因,9个山羊品种的期望杂合度（He）和观察杂合度（Ho）均在0.850以上,属于高杂合群体;9个山羊品种4个微卫星座位的PIC均值在0.820以上,属于高度多态微卫星DNA座位,可提供大量的遗传信息,具有遗传多样性评价优势,其中 PIC值最高的是圭山山羊（PIC=0.857）;主成分分析与UPGMA 聚类分析结果显示贵州白山羊、云岭山羊与圭山山羊亲缘关系较近,川东白山羊与板角山羊亲缘关系较近,湘东黑山羊、黄淮山羊与安徽白山羊亲缘关系较近,引入的波尔山羊自成一类,它与其他山羊亲缘关系较远。综上,9个山羊品种均具有较高的遗传多样性,其中圭山山羊的遗传多样性最丰富,贵州白山羊遗传多样性最低;各品种之间的亲缘关系符合不同品种的地理位置与育成史。     

中国黄牛六个毛色座位的遗传分化

根据国内２５个地方黄牛品种毛色资料，统计出６个具有显隐性毛色基因座位的等位基因频率，计算了不同座位的基因固定指数，品种内，品种间及群体的基因多样度，以及品种内和群体的ｓｈａｎｎｏｎ值，结果表明，中国不同黄牛品种具有不同程度的基因多样度，牛的毛色变异中有３４．１％是由品种间的差异造成的，毛色座位在品种间的分化程度较大。     

Genetic differentiation and gene flow among six sheep breeds of Mongolian group in China

The level of genetic differentiation, gene flow and the relationship between geographical distance and genetic differentiation among six sheep populations of Mongolian group in China (Tong sheep, small-tailed Han sheep, Hu sheep, Tan sheep, Ujumuqin sheep and Bayinbuluk sheep) were analyzed using seven microsatellites. The trees were constructed from diversity coefficient (DC) distances among the six sheep populations. The overall heterozygote deficit across all the populations (F _it) was between 0.167 (OarAE101) and 0.044 (MAF33). The over-all significant deficit of heterozygote, because of inbreeding within breeds, (F _is) was between 0.089 (OarFCB304) and 0.005 (MAF33). The coefficient of genetic differentiation (F _st) was between 0.100 (OarAE101) and 0.022 (OarFCB48). It indicated that 3.9% of the total genetic variation could be explained by breed differences and the remaining 96.1% by differences among individuals for each population. This illustrated that most variations existed within breeds and genetic differentiation level were very low among sheep breeds of the Mongolian Group in China. The average number of effective migrants exchanged per generation (Nem) ranged from 2.7369 (Tan sheep and Bayinbuluk sheep) to 44.3928 (Tong sheep and Hu sheep), and the mean value was 11.25213. Significantly positive relationships between the level of genetic differentiation and geographical distance and genetic distances were detected. It is concluded that genetic differentiation of sheep breeds of Mongolian group in China is mainly the result of natural selection (different living conditions). __________ Translated from Journal of Yangzhou University (Agricultural and Life Science Edition), 2007, 28(3): 22–26 [译自: 扬州大学学报(农业与生命科学版)]     

家鹅ND4基因多态性与遗传结构研究

四川白鹅、狮头鹅、豁眼鹅、伊犁鹅、朗德鹅和莱茵鹅是具有独特种质特性的家鹅品种.该试验利用直接测序法测定了具有独特种质特性,在鹅杂交育种中被广泛应用的四川白鹅等6个家鹅品种线粒体ND4基因的部分核苷酸序列(621 bp),共检测到了4种单倍型,4种单倍型的频率分别为0.467、0.033 3、0.467、0.033 3,单倍型多样性为0.582;各品种间的核苷酸分化系数(Nst)在0至1之间;6个家鹅各品种内核苷酸多样性(Pi)很低,各品种间的遗传距离(D)很小,遗传相似度高,而且同属于灰雁或鸿雁的家鹅品种之间的遗传相似度比分属于灰雁、鸿雁的家鹅品种之间的遗传相似度更高.另外,对这6个家鹅品种的遗传结构形成原因和杂交利用进行了初步分析.     

山东省猪种mtDNA CytB基因遗传多样性及系统进化研究

 【目的】利用mtDNA CytB基因为标记,从分子水平探讨12个猪种166个样本（8个山东省猪种,3个引进猪种和梅山猪种）的遗传多样性和各猪种间的亲缘关系,为山东省猪种合理利用以及生物多样性保护提供基础资料。【方法】对各猪种样本mtDNA CytB基因进行PCR扩增和测序,采用现代生物信息学方法进行数据处理分析。【结果】山东8个猪种种内遗传变异和种间遗传距离均较小,有共享单倍型。山东各猪种和梅山猪与大约克的遗传距离也较小,但与引进猪种杜洛克和长白的遗传距离较大。利用分子系统进化树和CytB基因4个SNP位点的分类方法将上述样本分为2个独立的支系,第一支以中国猪种为主,将除鲁烟白猪的一种单倍型在内的所有山东猪种、梅山猪和大约克的两种单倍型聚为一类,第二支以引进猪种为主,将长白、杜洛克、大约克的一种单倍型和鲁烟白猪的一种单倍型聚为一类。【结论】山东猪种有共同的母系祖先,品种内母系遗传多样性较贫乏;外来猪种引入山东后主要是用作父本以提高生产速度和瘦肉率等,对本地猪种未有母系贡献;利用CytB基因4个SNP位点对欧洲单倍型和亚洲单倍型的分类方法,可以方便地估测利用中外猪种结合培育的猪新品种（配套系）的母系血统情况。     

微卫星DNA标记对5个中外黄牛品种／群体遗传结构的研究

利用4种微卫星DNA标记对南阳牛、延边牛、韩牛、西门塔尔牛、皮埃蒙特牛×南阳牛杂种5个品种／群体的等位基因频率、杂合度、有效等位基因数、遗传距离等进行了遗传检测,在此基础上又进行了聚类分析。从分子水平上揭示了中国牛与外国牛、瘤牛与普通牛品种间的遗传结构关系。     

5个重庆地方猪种遗传多样性的微卫星分析

目的通过微卫星标记评估8个安徽地方猪品种的遗传多样性。方法采用PCR和聚丙烯酰胺凝胶电泳对FAO-ISAG联合推荐的15个微卫星标记进行分型,并计算有效等位基因数 (N_e)、期望杂合度 (H_e)、多态信息含量 (PIC)、F统计量和遗传距离等参数,探讨品种间的遗传多样性和遗传关系。结果15个微卫星标记共检测到272个等位基因,平均有效等位基因数9.561 2个。8个品种的有效等位基因数在2.445 1~3.786 6之间,期望杂合度在0.532 0~0.714 8之间,多态信息含量在0.369 8~0.890 6之间。F统计量和基因流 (N_m) 分析表明：安徽地方猪品种间存在一定程度的近交和基因流动。基于Nei氏遗传距离 (D_s) 构建系统发生树显示：8个地方猪种可分为两类：一类为皖南花猪;另一类又聚为两小支,一小支为安庆六白猪、圩猪和霍寿黑猪,另一小支为皖北猪、皖南黑猪、枞阳黑猪和定远猪。结论8个安徽地方猪种遗传多样性丰富,群体内存在一定程度的近交和基因流动。结果为安徽地方猪种的保护和利用提供了理论依据。     

鸡品种随机引物扩增多态DNA的研究

用12个随机引物对6个鸡品种60个个体核DNA进行了RAPD扩增,共检出223条扩增片断,多态性片断188条,占843%。反映了品种内和品种间的遗传变异。12个引物对60个个体分别扩增出16,21,22,17,17,20,22,12,18,23,18,16条带。品种内和品种间遗传相似度变异范围为07981～08685和05993～07813。肉鸡AA品种内变异程度最大,且与伊莎褐遗传距离最大为04007。海兰白和海赛克斯褐首先聚类。肉鸡AA在UPGMA法中与海兰褐聚类后再与其它4种蛋鸡聚类。在NJ法中与海兰褐和其它4种蛋鸡的聚合同时聚类。说明了肉鸡AA与5种蛋鸡品种的距离较远。12个引物在6个鸡品种共检测到7条品种特异带和3条与性别相关带。     

定量免疫电泳技术对黄牛品种间遗传差异的研究

本文用定量免疫电泳技术对4个黄牛品种间的遗传差异作了免疫遗传学研究。结果表明,所研究的4个品种间的遗传相似度分别为:文山牛—昭通牛为0.922,文山牛—黑白花牛为0.917,文山牛—莫瑞灰牛为0.742,昭通牛—黑白花牛为0.795,昭通牛—莫瑞灰牛为0.603,黑白花牛—莫瑞灰牛为0.818基于上述遗传相似度,本文还作了4个品种亲缘关系的聚类分析。     

定量免疫电泳技术对黄牛品种间遗传差异的研究

 本文用定量免疫电泳技术对4个黄牛品种间的遗传差异作了免疫遗传学研究。结果表明,所研究的4个品种间的遗传相似度分别为:文山牛—昭通牛为0.922,文山牛—黑白花牛为0.917,文山牛—莫瑞灰牛为0.742,昭通牛—黑白花牛为0.795,昭通牛—莫瑞灰牛为0.603,黑白花牛—莫瑞灰牛为0.818基于上述遗传相似度,本文还作了4个品种亲缘关系的聚类分析。     

运用荧光标记微卫星分析6个肉山羊品种遗传多样性

为了研究安徽白山羊、贵州白山羊、陕南白山羊、宜昌白山羊、马头山羊和波尔山羊6个肉山羊品种DNA分子水平上的遗传多样性,利用10个微卫星引物,分析6个肉山羊品种分子水平上的遗传变异和群体关系。10个微卫星位点均呈现高度多态,其多态信息含量(PIC)在0.531～0.812之间。F统计结果显示群体间存在极显著的遗传分化,遗传分化系数(Fst)为0.082。系统进化树NJ图把中国5个肉山羊和波尔山羊分为2支;中国肉山羊又被分成2个分支。系统进化树UPGMA图和主成分的二维坐标图进一步证实上述聚类结果的可靠性。此研究结果显示6个肉山羊品种遗传多样性丰富,具有很大的选育潜力,特别是中国地方品种,是将来开发利用的宝贵原始材料。