【作者】 杜小勇；

【导师】 余梅；

【作者基本信息】 华中农业大学 ， 动物遗传育种与繁殖， 2008， 硕士

【摘要】 家山羊是中国重要的畜种。近年来由于商业品种的引入导致地方品种山羊数量的锐减,甚至有些品种处于濒危状态。我国地方山羊品种的遗传多样性研究势在必行。本研究利用微卫星标记对中国10个地方山羊品种(河西绒山羊、中卫山羊、陕南白山羊、黄槐山羊、伏牛白山羊、沂蒙黑山羊、鲁北白山羊、太行山羊、吕梁黑山羊、济宁青山羊)及1个引进品种波尔山羊共计530个个体的遗传多样性进行了分析研究。结果如下:1.采用SRCRSP5、MAF209、TGLA53、ETH10、OarAE54、CSRD247、SRCRSP15、SRCRSP3、MAF065、SRCRSP8、SPS113、INRABERN172、OarFCB20、McM527、ILSTS087和DRBP1共计16个微卫星座位对11个山羊品种进行了遗传多样性分析,共检测到181个等位基因,平均每个位点检测到11.31个等位基因;品种特有等位基因总计28个。表明这16个FAO—ISAG推荐的微卫星座位能用于我国地方山羊遗传多样性的检测,也表明了我国山羊品种遗传多样性丰富。2.计算了16个微卫星座位在11个山羊品种的等位基因频率,并以其为基础获得了各群体的平均杂合度、平均多态信息含量和平均有效等位基因数和群体内近交系数,分别为0.605、0.630、3.348和0.126,表明群体内的遗传变异丰富,也表明我国地方山羊品种的遗传多样性比引进品种波尔山羊高。3群体间基因流分析结果表明太行山羊和河西绒山羊之间有较大的基因流(17.866),太行山羊和黄淮山羊间的基因流次之(16.76),而其它的群体之间的基因流基本在一个较高水平(均值和标准偏差为8.46±4.81):分子方差分析也显示95.79%的遗传变异来源于群体内个体间,只有4.11%的遗传变异来源于不同群体间的分化。上述结果表明这10个地方山羊群体间变异小。4.本研究的16个微卫星座位在11个山羊群体中总体上极显著偏离哈代-温伯格平衡,总体上处于杂合子缺失状态(P＜0.01);从群体看,16个座位总体上在每个山羊群体都偏离哈代-温伯格平衡。从座位看,11个山羊总体上在CSRD247、ETH10、OARAE54、SRCRSP5、INRABERN172和MCM527座位处于HW平衡(P＞0.05),MAF209、SRCRSP15、ILSTS087和MAF65座位显著的偏离HW平衡(0.05＜P＜0.01),SRCRSP3 TGLA53 DRBP1、OARFCB20、SPS113和SRCRSP8座位极显著的偏离哈代-温伯格平衡(P＜0.01)。连锁平衡检验结果表明在1320对座位配对/群体中,有638对显著或者极显著(P＜0.05或P＜0.01)偏离连锁平衡,但没有任何座位配对出现持续的连锁平衡偏离。5.采用了基于遗传距离的聚类分析、主成分分析和基于贝叶斯模型的聚类分析三种方法研究了10个地方山羊群体间的遗传关系。计算了每两群体间的Nei氏标准遗传距离(D_S)和,用非加权组对算术平均法(UPGMA)和邻近结合法(NJ)构建了4个11个中外山羊群体的系统进化树图(D_A/NJ、D_s/NJ、D_A/UPGMA和D_s/UPGM图)并得到较高的Bootstrap检验聚类值,4种聚类图大同小异。主成分分析结果得到10个成分,第一主成分和第二主成分分别占45.35%和17.35%,散点图表明引进品种与10个中国地方品种明显分开,10个地方山羊品种遗传分化较低,按主成分分两类,并可细分为4类。基于贝叶斯模型的群体结构分别分析11个山羊群体中的群体和个体的的遗传结构,K=2时,聚类图中波尔山羊很明显的与10个中国地方山羊群体区分开。k=3时,可根据聚类图中的不同颜色填充区域范围将10个中国地方山羊群体划分为两类。K=4,k=5时,群体或者个体Q值普遍变小,难以聚类。基于遗传距离的聚类分析中的Ds/NJ系统进化树图、主成分分析的前两个主成份分析和基于贝叶斯模型聚类分析中的按K=3时个体Q值所得的遗传结构分析这三个结果一致表明,陕南白山羊、济宁青山羊、鲁北白山羊、黄淮山羊聚为一类,沂蒙黑山羊、太行山羊、伏牛白山羊、河西绒山羊、吕梁黑山羊、中卫山羊聚为一类,波尔山羊单独聚为一类。更多还原

【Abstract】 The domestic goat is one of the important livestock species in China.The size of each breed dramatilly and many of them were endangred in recent years because of introduced commercial breeds.Studying on the genetie diversity of Chinese indigenous goat breeds have been carryed out in nowadays.The microsatellite loci were used in this experiment to analysis the genetic diversity of 530 goats from ten indigenous breeds (Shannan White,Hexi cashmere,Zhongwei,Funiu White,Huanghuai,Jining Grey, Yimeng Black,Lubei White,Lvliang Black,Taihang goat) and one introduced breed (Boer Goat).The research results of this study are as the followings;1.Based on the 16 microsatellites loci,we analyze the genetic variation of 11 goat populations.Among loci,the mean number of alleles was 11.31,which proved that the microsatellites recommended by FAO-ISAG are useful for the biodiversity studies in Chinese indigenous goat breeds.2.The observed heterozygosities(Ho),polymorphism information content(PIC), Effective number of alleles(Ne) and inbreeding coefficients(Fis) calculated besed on allele frequency in this 11 breeds is 0.605、0.630、3.348 and 0.126,respectively.The results showed that the genetic variations are abundan in Chinese indigenous goat populations.3.The level of gene flow from Taihang goat into Hexi cashmere goat is very high, followed that between Taihang goat and Huanghuai goat.the gene flow among others is almost in a same higher level(Mean±SD is 8.46±4.81).The mean Fst(0.64) for only Chinese native goat populations suggests that 93.6%of the total genetic variation was from genetic differentiation within each breed and 6.4%of the genetic variation existed among populations,which was also supported by Analysis of Molecular Variance.4.The HWE test showed that all loci gave a deviation when analyzed across population.Deviations from HWE across the loci were present in all of the 11 populations. Deviations from HWE across the population were present in MAF209,SRCRSP15, ILSTS087,MAF65,SRCRSP3,TGLA53,DRBP1,OARFCB20,SPS113 and SRCRSP8 (P＜0.05).Out of 1320 locus pair/population combinations,Exact tests for LE between all marker pairs were carried out within each of the populations and resulted in 638 significant(P＜0.05) outcomes,which were sporadically distributed among the populations,but no specific locus pairshowed a consistent deviation from LE that would have been in each,or even in most,of the populations.5.Three approaches were employed to investigate the genetic relationships among the populations.Firstly,DA and Ds distance matrices were used to build phylogenetic trees with UPGMA and NJ methods.The four Phylogenetic trees are nearly the same. Secondly,in a Principal Component Analysis,the first and second principal component accounted for 45.35%and 17.35%of the variance.The scatterplot revealed that the introduced population is distant from the indigenous population,genetic differentiation among the indigenous breeds is in low level,and the 10 indigenous breeds were clustered into two distinct groups.Thirdly,Population structure analysis based on a Bayesian clustering method showed that a splitting solution was found for K=2 runs in which Boer Goat were identified as distinctive.At K=3,additional structure was detected and the new splitting appeared in Chinese indigeous goat populations.At K=4 or K=5, Inferred membership coefficients of population or individual is very small and could not be applied to clustering well.In a word,the results from Ds/NJ genetic distance cluster, Principal Component Analysis and population genetic structure analysis indicated that the 10 indigenous populations can be clustered into two distinct groups:one group includes Shannan White,Jining Grey,Lubei White,Huanghuai Goat;the other group includes Yimeng Black,Taihang Goat,Funiu White,Hexi cashmere,Lvliang Black,Zhongwei Goat.更多还原