【作者】 李锋；

【导师】 徐照学；

【作者基本信息】 河南农业大学 ， 动物遗传育种与繁殖， 2012， 硕士

【摘要】 随着近几年对肉制品需求层次的多样化，国内肉牛品种改良在科技的带动与支撑下速度飞速发展，各地出现了逐步稳定的杂交品系，本实验共采集了四个地方的肉牛样本来进行分析，通过不同的方式来加以验证分析目前的地方品种的育种效果，并且针对中国西门塔尔牛血样，通过发现分析候选基因多态与屠宰性状关联性，来综合分析该品种的基因稳定性，为进一步进行的品种改良提供参考依据。本实验共采集了夏南牛138头，秦川牛136头，西杂牛176头以及中国西门塔尔牛60头的生长生产性状数据，主要包括了身高，体重，胴体重，眼肌面积，B超测定眼肌面积，背膘厚度，B超测定背膘厚度，B超测定肌间脂肪，眼肌重，西冷重，上脑重，高档肉重，大理石花纹级别等数据。本实验共分为两部分，第一部分，对四个品种牛进行数据整理对比，关联分析，找出其屠宰性状规律，并且结合当时当地实际情况来分析实验数据结果；第二部分对采集的60份中国西门塔尔牛样本为研究材料，采用DNA测序、DNA序列分析、PCR-SSCP等技术，检测了MC3R，MC4R，Leptin基因的遗传变异，分析了其遗传结构和遗传多样性，并将上述3个基因的多态性与中国西门塔尔牛屠宰性状进行了关联性分析，以期获得相应的分子遗传学信息，探索这些基因对中国西门塔尔牛的遗传效应，找到对重要经济性状具有显著效应的遗传标记，以期对中国西门塔尔的育种改良提供参考。值得注意的是，本实验在收集生长生产性状的过程中，引入兽用B超对品种牛进行了部分生产性状活体检测，并收集了屠宰后的该指标进行关联分析，发现不同品种时间关联系数不同，在遗传稳定的品种内，可以构建关联系数，从而更准确高效的的服务育种工作。实验结果如下：实验第一部分：采用SPASS17.0对采集数据进行归纳比较得出以下结论：1、在体重、胴体重、高档肉重的比对中，西杂牛高于夏南牛，夏南牛高于秦川牛，差异均极显著。在眼肌面积比对中，夏南牛与西杂牛极显著高于秦川牛。在背膘厚度的比对中，秦川牛极显著高于夏南牛和西杂牛。2、秦川牛内不同性别屠宰性状比对在秦川牛中进行的不同性别的比对中可以看出，阉牛的各类数据都表现非常突出，在体高、体重、背膘厚度、西冷肉重以及上脑肉重方面与公母牛相比差异极显著。3、不同品种内，眼肌面积与屠宰性状关联性眼肌面积在与屠宰性状关联分析中可以看出，在夏南牛中，眼肌面积与胴体重，眼肌重，高档肉重呈现强相关，秦川牛中眼肌面积与西冷重呈现强相关，西杂牛中，眼肌面积与胴体重，眼肌重，西冷重呈现强相关。4、兽用B超活体测定数据与实测数据关联性在活体测定的眼肌面积、背膘厚度与屠宰后的该性状进行关联分析过程中可以看出，整体呈现中度相关。实验第二部分:1.本实验共检测了三个基因的多态性，对MC3R与MC4R基因进行PCR-SSCP检测并进行双向测序，没有发现多态位点，在对Leptin基因检测中，共发现了四个多态位点，分别为S978，S3521，S3822以及S4091位点，S978位于5’非翻译区内，而S3521,S3822,S4029均处在3’UTR区域内。由于携带S4091位点突变的个体数仅有一个，我们在此不做深入分析，其余三个突变位点均表现为低度多态（PIC<0.25），独立性检验结果差异不显著，处于Hardy Weinberg平衡状态，AA基因型为在该群体中优势基因型,这些数据说明了这三个基因在该群体内高度保守。由于整群牛是乌拉盖牧场自繁自养的中国西门塔尔牛，在相对封闭的环境内，群体自身遗传信息逐步稳定，也是低度多态位点的原因之一。2.在多态位点与屠宰性状的关联分析中发现，5’非翻译区内S978，3’UTR区域内S3521与屠宰性状关联性较强，3’UTR区域内S3822为沉默突变。S978突变能够显著影响肌间脂肪含量，突变杂合子AB基因型肌间脂肪显著高于纯合子S978AA基因型，S3521突变不仅能够显著影响到肌间脂肪，而且对胴体重和眼肌面积也有非常显著的影响，携带S3521突变AB基因型的个体肌间脂肪、胴体重、眼肌面积均极显著高于AA基因型个体。位于3‘UTR区域的沉默突变S3822位点的不同基因型之间有差异但是没有达到显著水平，没有对屠宰性状指标呈现出显著相关联性，尽管沉默突变没有改变氨基酸的组成，但也可能改变了蛋白的合成速度，因此对生物体产生不显著影响，促进动物生长，该结论有待进一步的试验证明。更多还原

【Abstract】 This paper studied were collected from the four parts of the beef cattle samples analyze thedifferent ways to verify the effect of the analysis of local varieties of breeding and molecularexperiments, and for Chinese Simmental analysis, analysis of candidate gene polymorphismsassociated with carcass traits, and comprehensive analysis of the species through the discoverygenetic stability, to provide a reference for further improved varieties.This experiment were collected the growth and production traits, about138Xia nan cattle, Qinchuan136Simmental hybrid cattle176, and Chinese Simmental60,including height, weight,carcass weight, loin eye area. eye muscle weight, sirloin weight on brain weight, high-grade meatweight, marbling level and backfat thickness intramuscular fat,eye muscle area by B ultrasoundwhich by comparison of the data association analysis to discover the law of the growth ofproduction of four varieties., which provide a reference for the beef cattle breeding.In this study is divided into two parts, Firstly, compared the data processing to four species ofcattle, to identify the growth of production rules, and combined with t the actual situation toanalyze the experimental data and discuss the results; Secondly, part of the acquisition of60Chinese the Simmental sample for research material, the use of DNA sequencing, DNA sequenceanalysis by PCR-SSCP and other technologies, to detect the genetic variation of the MC3R,MC4R, Leptin analysis of its genetic structure and genetic diversity, and analysis the relationshipbetween the three genes polymorphisms and Chinese Simmental carcass traits, and moleculargenetics in order to explore the genetic effects of these genes in Chinese Simmental, find asignificant effect on the important economic traits genetic markers to provide a reference forChinese Simmental breeding improvement.It is noteworthy that, in the process of collecting the growth and production traits, theexperimental introduction of veterinary B ultrasound in vivo detection of production traits on thespecies of cattle, and collected after slaughtering the indicator correlation analysis found that thetime correlation coefficient of different species different varieties of genetically stable, one canconstruct the correlation coefficient, and thus more accurate and efficient service and breeding.Veterinary B ultrasound in vivo, the experimental measurement of eye muscle area, backfatthickness, measured after intramuscular fat and slaughter loin eye area, backfat thickness, intramuscular fat were analyzed by Chinese Simmental.The results were as follows:Part11. In the process of three varieties of the same trait found the weight of Simmental and Xia nancattle, Qin chuan the difference was significant (P <0.01), significantly higher than the other twovarieties; the Qin chuan backfat thickness compared to Xia nan cattle, Simmental difference wassignificant (P <0.01), significantly higher than those of Xia nan cattle and Simmental; the Qinchuan ocular weight was significantly higher than in summer Southern cattle and Simmental (P<0.05); the Qin chuan upscale meat production and Xia nan cattle and Simmental significantdifference (P <0.01), significantly lower than Xia nan cattle and Simmental.2. The comparation between the growth and production traits with gender in the Qin chuancattle,which found castrated bull of body height, weight, carcass weight, loin eye area, backfatthickness, sirloin meat weight, as well as on the brain meat weight,was very significant (P <0.01),bull’s body weight, loin eye area, brain weight, eye muscle weight as well as high-grade meatweight than cow of the data differences significant (P <0.05).3. Eye muscle area and backfat thickness of the four varieties of cattle were measured with Bultrasound, and found that the traits were slaughtered than the correlation coefficient differencesof the different species of conducting eye muscle area associated analysis found in the Simmental,the highest correlation coefficient (R=.656) the Qin chuan lowest correlation coefficient (R=0.148), found in the correlation analysis of the backfat thickness Xia nan cattle, the highestcorrelation coefficient (R=0.723).Chinese Simmental the lowest correlation coefficient (R=0.219).4. Between different species, eye muscle area and carcass weight, eye muscle weight, high-grademeat weight, as well as on the brain, and sirloin weight associated analysis found that, ChineseSimmental, loin eye area and carcass weight correlation coefficient of0.546; Xia nan cattlecarcass traits associated with eye muscle area coefficient for high-grade meat weight (R=0.756),the lowest correlation coefficient for brain weight (R=0.459); Qin chuan cattle in slaughter traitsassociated with eye muscle area coefficient highest Western cold weight (R=.658), the lowestcorrelation coefficient is on brain weight (R=0.374); Simmental slaughter traits and eye musclearea of the highest correlation coefficient for the Sirloin (R=0.820).the lowest brain weight (R=0.499).Part21. The varations of two loci in MC3R gene were studied. No polymorphism in MC3R genewas detected in the studied population. The varations of there loci in MC4R gene were studied. No polymorphism in MC4R gene was detected in the studied population.2. Relationship between genetic variation of Letpin gene and slaughter performance inChinese Simmental.The varations of four loci in Leptin gene were studied. Four SNPs (978T>C,3521G>C，3822C>T,4029T>C, ref. BTU50365) were detected in Leptin gene for thefirst time. The association between S978polymorphism and slaughter performance in ChineseSimmental was analyzed. The individuals carried978C allele had higher intermuscularfat.The association between S3521polymorphism and slaughter performance in ChineseSimmental was analyzed.The individuals carried3521C allele had higher intermuscular fat,carcass weight and marbling. The association between S3822and S4029polymorphismand slaughter performance in Chinese were analyzed.The results indicated that it didn，tinfluence the slaughter performance in Chinese Simmental.更多还原