【作者】 李长龙；

【导师】 潘玉春；

【作者基本信息】 东北农业大学 ， 动物遗传育种与繁殖， 2004， 硕士

【摘要】 随着生活水平不断改善，人们对于猪肉品质要求越来越高。可以肯定，改良肉质性状将是我国未来动物育种工作中的重点。在人类的研究中，已经发现脂肪细胞分化和决定因子-1(ADD1)基因与脂肪外组织的脂肪沉积有着确定的连锁关系。ADD1基因同PPAR基因、C/EBP基因共同调控脂肪细胞的分化，同时参与低密度脂蛋白(LDL)受体、乙酰辐酶A羧化酶(ACC)、脂肪酸合成酶(FAS)、葡萄糖激酶(GK)、磷酸烯醇式丙酮酸羧激酶(PEPCK)等有关脂肪合成和葡萄糖代谢的基因的表达。最近的研究表明，ADD1基因能够调节非脂肪组织的脂肪沉积。有鉴于此，本研究以猪ADD1基因为猪肉质性状的候选基因来研究猪ADD1基因多态与肉质性状的相关性。具体工作极其结论如下： (1)ADD1的克隆和表达：利用同源克隆的方法首次克隆猪ADD1基因的全长编码序列和部分DNA序列。经过同源性分析和蛋白质三维保守性结构分析以及southern杂交分析，结果表明：所克隆序列是猪ADD1基因。 (2)ADD1的表达规律：用RT-PCR的方法检测了猪10种组织的RNA表达量。结果显示在心、脾、肺、肾、胃、大肠、小肠、肌肉、脂肪等组织都有ADD1基因的表达。在脂肪组织中表达量最高，在肌肉组织中表达量最低。为ADD1基因与肉质性状的连锁的研究奠定了理论基础。 (3)ADD1基因的SNP与肉质性状的相关性分析：利用PCR-SSCP方法扫描了部分DNA序列，发现了一个SNP。在两个试验组(不同的品种和营养因子效应)中检测ADD1基因的不同基因型，并且根据不同的试验组构建不同统计分析模型对ADD1基因的SNP与肉质性状进行相关分析。结果显示：在试验组A(存在对肉质有显著影响的营养因子效应)中，ADD1基因AB型和BB型在肉色和肌内脂肪上存在显著差异(P＜0.05=，并且AB型与BB型相比有较高的肌内脂肪含量、浅的肉色。各个营养组间肉色、肌内脂肪含量、蛋白质含量、pH值等指标差异极显著(P＜0.01)。在试验组B(存在对肉质有显著影响的品种效应)中，ADD1基因AA型和BB型间在肉色、肌内脂肪和嫩度上存在显著差异(P＜0.05)，并且AA型有较高的肌内脂肪含量、浅的肉色和较高的嫩度。据此认为，猪ADD1基因的SNP与肌内脂肪、肉色等肉质性状有确定的相关关系，ADD1基因是这些性状的主基因或与主基因连锁。利用生物学软件分析突变对RNA二级结构和蛋白质等电点、结构跨膜、蛋白酶酶切位点。发现突变只导致产生了一给蛋白酶酶切位点，其他未有变化。蛋白酶酶切位点的变化可能是ADD1基因与肉质性状相连锁的主要因素。更多还原

【Abstract】 People will require high quality pork with ceaseless improve of live level. It is doubtless that improve meat quality is emphases in animal breeds in the future. In human research, there is doubtless association between adipocyte determination and differentiation factor (ADD1) gene and aggradation of fat out of the non-fat tissue. ADD 1 gene, PPAR gene and CEBP gene regulate corporately process of adipocyte differentiation. AT the same time, ADD1 gene regulate expression of LDLR gene.ACC gene.FAS gene, GK gene, PEPCK gene etc, which have important role in adipocyte synthesis and metabolism of glucose. Recently research show, ADD1 gene can regulate fat aggradation in non-fat tissue. Therefore, we research the association between ADD1 gene SNP of ADD 1 gene and meat quality as a candidate gene. The works and conclusions show:(1) Cloning of ADD1 geneIt is first time that cloning porcine complete ADD1 cDNA sequence and partial sequence DNA. We can identify the sequence with analysis of homogeneous, conservative structure of protein three structure, Southern bloting. The cDNA sequence has submitted to GenBank (Accession No. AY496867), The DNA sequence has submitted to GenBank (Accession No. AY272051).(2) Expression of ADD1 geneWe have analysis of ADD 1 gene expression in ten tissues of heart, liver, spleen, lung, kidney, stomach, large intestine, small intestine, and muscle, fat, with half ration RT-PCR. The result show all tissue have expression of ADD1 gene except for liver and the highest expression in fat tissue, the lowest expression in muscle tissue. All of this is theory of basic of association between meat qualities with ADD1 gene.(3) Analysis between the SNP of ADD1 gene with meat qualitySNP have been found after scan partial DNA sequence. We have detected different genotypes in two groups, different feed factor and different breed factor, with PCE-SSCP. We have designed different modules in different groups to analysis association between SNP with meat quality. The result in A group show, AB genotype and BB genotype have significant difference (P<0.05)in color and intramuscule, AB genotype has higher intramuscule and lighter meat color, different feed factor have very significant difference(P<0.01) in meat color, intramuscule, protein, pH value. The result of B group show, There is between significant difference (P<0.05)in meat color, intramuscule, tendness, and BB genotype has higher intramuscule and tendness, lighter meat color. Different breed factor have very significant difference(P<0.01) in all index. In conclusion, there is association between the SNP of ADD 1 and porcine meat quality, and ADD1 gene is major gene or association with major gene. We have only found a locus of proteolysis enzyme with biologic softwareanalysis RNA second structure and third structure, isoelectric point, transmembrane segments, locus of proteolysis enzyme. It is conceivable reason of association between the SNP of ADD1 and porcine meat quality.更多还原