【作者】 任斌；

【导师】 黄生强；

【作者基本信息】 湖南农业大学 ， 动物遗传育种与繁殖， 2008， 硕士

【摘要】 本试验以10个猪种/群,包括:外来品种杜洛克猪、大白猪、长白猪、湖南地方品种宁乡猪、湖南黑猪、大围子猪、沙子岭猪、海南五指山猪、杂种猪长大(LY)和杜长大(DLY)共923头猪为研究对象,采用PCR-RFLP方法分析了AMPD1基因、MYF6基因的遗传多态性及基因频率和基因型频率,并对品种间基因型频率进行了卡方检验。同时,结合屠宰性能记录,国内首次在猪上研究了AMPD1基因不同基因型对胴体性状和肉质性状的遗传效应,同时对MYF6基因不同基因型对胴体性状和肉质性状的遗传效应也做了相关研究。主要结果如下:1 AMPD1基因1.1在湖南地方猪种宁乡猪、大围子猪、沙子岭猪、五指山猪、湖南黑猪、三个外来猪品种、杜长大和长大十个猪种群体中,AMPD1基因的RsaI酶切位点均存在较丰富的多态性:宁乡猪、大围子猪、沙子岭猪、湖南黑猪和海南地方猪五指山猪中都检测到有从、AC、CC三种基因型个体的分布:在三个外来品种猪中,没有检测到CC基因型个体:在杂交猪群体中,AA基因型有较高分布,等位基因A为优势基因:1.2杜洛克、长白猪、大白猪、杜长大和长大猪在后腿比例性状上差异显著(P＜0.05),AC基因型个体比AA基因型个体分别高:22.76%、16.80%、17.09%、21.95%、20.69%,选择AC型能提高后腿比例:在大白猪和长白猪中,在实测平均膘厚性状上,AC基因型个体比从基因型个体分别低:30%和26.36%,选择AC基因型能明显降低实测平均膘厚、提高瘦肉率;在杜洛克和长白猪中,选择AC基因型能显著的降低平均皮厚和脂率;1.3在失水率性状上,杜洛克、长白猪、大白猪、杜长大和长大杂交猪中,AC基因型个体比AA基因型个体分别低1.50%、6.68%、35.91%、1.25%和30.92%,选择AC基因型能降低失水率:在五个被检测的猪种/群体中,AC基因型的贮存损失高于从基因型的贮存损失。2 MYFd基因2.1在三个外国猪种群体以及长大、杜长大猪群体中,MYF6基因的MspI酶切位点均存在较丰富的多态性,而在地方品种中无多态性或多态性不明显;在湖南地方猪种及海南五指山猪中,没有检测到CC基因型个体,等位基因T为优势基因:在三个外来品种中,等位基因C为其优势基因,而且长白猪C等位基因频率最高,杜洛克最低;在长大和杜长大中优势基因为等位基因C;2.2杜洛克、长白猪、大白猪、杜长大和长大猪种/群体中,在脂率性状上,CC基因型个体比TT基因型个体分别低:97.06%、15.20%、10.67%、22.91%和19.61%,选择CC型能明显降低脂率;在大白猪和长大杂交猪中,在实测平均背膘厚性状上,CC基因型个体比TT基因型个体分别低:38.91%和:36.85%,CC基因型个体具有较薄的背膘厚和较高的瘦肉率,等位基因C具有一定的正效应;2.3在失水率性状上,C等位基因对大白猪具有增加失水率的负效应,而对长白猪有降低失水率的正效应,在其它猪种上,作用不明显;在贮存损失性状上,C等位基因具有增加贮存损失的负效应。本研究结果表明,AMPD1基因、MYF6因有望成为与背膘厚、瘦肉率、部分胴体性状和失水率及贮存损失性状相关的一个主要侯选基因或分子标记。更多还原

【Abstract】 By adopting Polymerase Chain Reaction-Restrain Fragment Length Polymorphism(PCR-RFCP),the genetic variations of AMPD1 and MYF6 gene were detected in 923 pigs including 10 groups:Duroc,Yorkshire,Landrace,Hybrid breeds: DL Y(Duroc×Landrace×Yorkshire),LY(Landrace×Yorkshire),Ningxiang,Daweizi, Taoyuan、Shaziling、Wuzhishan.Then the genotype frequencies and gene frequencies were calculated according to the PCR-RFLP.The differences of genotype frequencies between groups were analyzed by Chi Square Test.At the same time,the effects on meat-quality traits and carcass traits of AMPD1 gene which was the first studied on pigs in China and MYF6 gene were estimated according to their slaughter datu.The main results are showed as follows:1.The genetic polymorphism and effect of AMPD1gene.1.1 There were great polymorphisms in RsaⅠrestriction loci of AMPD1 gene in Ningxiang,Daweizi,Shaziling,Taoyuan,Wuzhishan,three types of exotic-breeds. DLY and LY breeds;genotype AA,AC,CC were found in the native breeds Ningxiang,Daweizi.Shaziling,Taoyuan and Wuzhishan;genotype CC could be found in none of the exotic breeds:Duroc,Landrace and Yorkshire;Allele A was the superiority allele in the hybrid breeds;1.2 The traits of hind leg proportion were different in these five breeds:Duroc, Yorkshire,Landrace,DLY and LY.The individuals with AC genotype were taller by 22.76%,16.80%,17.90%,21.95%,and20.69%respectively than individuals with AA genotype’s.If the AC genotype selected,the hind leg proportion would be enhanced. As to the traits of average fat thickness,the Yorkshire and Landrace individuals with AC genotype were lower than individuals with AA genotype by30%and26.36%,and If the AC genotype selected,the average fat thickness would be reduced and the lean percentage would be increased distinctly.On the two breeds of Duroc and Landrace,Selecting the AC genotype could reduce average skin thickness and fat percentage efficiently.1.3 Concerning the water loss traits of these five breeds:Duroc.Yorkshire, Landrace,DLYand LY,the individuals with AC genotype were lower than the ones with AA genotype by 1.50%,6.68%,35.91%,1.25%and 30.92%respectively,and Selecting the AC genotype could reduce the water loss.The AC genotype had significant higher in the drip loss than the AA ’s.2.The genetic polymorphism and effects of MYF6 gene2.1 In the three types of exotic breeds and DLY,LY,there were great polymorphisms in MspⅠrestriction loci of MYF6 gene,whereas there were little or no polymorphisms in native breeds;in local breeds,there were no CC genotype and Allele T was the superiority allele;in the exotic breeds,Allele C was the superiority allele,and the highest frequency was Yorkshire,the lowest was Duroc;Allele C was the superiority allele in DLY and LY;2.2 With regard to trait of fat percentage,the individuals with CC genotype were lower than the ones with TT genotype by 97.06%,15.2%,10.67%,22.91%and 19.16% respectively.Selecting the CC genotype could reduce the fat percentage obviously.On the two breeds,Yorkshire and LY,individuals with CC genotype had lower average measured back fat thickness by 38.92%and 36.85%respectively than that of the ones with TT genotype.Individuals with CC genotype had thinner back fat thickness and higher lean percentage,and allele C took on certain positive effect.2.3 On the water loss trait of Yorkshire breed,Allele C operated negatively in increasing the Water loss percentage;while on the water loss trait of Landrace, Allele C operated positively in decreasing the water loss percentage.But the results were not so distinct on other breeds.On the trait of Drip loss,Allele C operated negatively in increasing Drip loss.The studies indicates that AMPD1 and MYF6 genes could be used as candidate genes or molecular marker related to the back fat thickness,lean percentage,partial carcass traits,water loss and drip loss traits.更多还原