【作者】 许盛海；

【导师】 陈国宏；

【作者基本信息】 扬州大学 ， 动物遗传育种与繁殖， 2007， 硕士

【摘要】 生长激素(Growth Hormone, GH)是动物出生后调节生长的最主要激素,对动物有显著加快肌肉、骨骼生长,降低脂肪含量,促进生长发育等作用。本研究以鸭生长激素基因为研究对象,根据其序列(GenBank登录号为:AB158760)利用PCR-SSCP方法对北京鸭、樱桃谷鸭、西湖野鸭、绍兴鸭、山麻鸭、荆江鸭、金定鸭、缙云麻鸭等8个鸭品种生长激素基因整个编码区、调控区及内含子2、3区段进行单核苷酸多态性(SNP)扫描,分析是否存在多态性,比较不同品种的基因型频率,并探讨不同基因型与鸭种质特性之间的关系,为今后育种过程中的标记辅助选择(MAS)提供理论依据。结果如下:1.鸭生长激素基因5′调控区和3′调控区共检测出多态位点2个:5′调控区发现了2处(230处C→G和244处C→A),在3′调控区没有发现多态性,说明3′调控区是高度保守的区域。统计结果发现:5′调控区在北京鸭、西湖野鸭、樱桃谷鸭、山麻鸭、缙云麻鸭中趋于纯合保守,在绍兴鸭、荆江鸭中变异也相对较小,而在金定鸭中表现出较大的变异性,这反映出了金定鸭较为独特的种质特征。2.鸭生长激素基因编码区共检测出多态位点1个,即第4外显子3701处发现C→T,但表现为沉默突变。该基因座的基因型频率和基因频率分布与品种有关,肉用型鸭CC基因型频率显著高于蛋用型,即等位基因C和D分别是肉用型和蛋用型的优势基因。另外,等位基因C频率最高的北京鸭和樱桃谷鸭属于高产肉用型,而等位基因D频率最高的金定鸭和绍兴鸭属于高产蛋用型鸭种。3.鸭生长激素基因内含子2、3的共检测出多态位点8个:在2593,2770,2813,2829,2894,2896,3100,3270处分别发生C→T,G→A,T→A,C→A,C→T,T→C,C→G,A→G。统计结果发现:北京鸭、樱桃谷鸭除在内含子2的2593处表现出变异性,在其他位点都趋向于纯合保守,表现了一定程度的品种保守性;绍兴鸭几乎在所有位点都相对趋向于纯合保守,也表现了较强的品种保守性;而其他品种各个位点总体上具有丰富的多态性,表现了品种的变异性。可见,在生长激素基因内含子2、3的变异水平上,北京鸭、樱桃谷鸭、绍兴鸭表现出了独特的种质特征。更多还原

【Abstract】 Growth hormone is one of the foremost hormone in regulating growth after animals are born, it could remarkable expedite the growth of muscles and bones, reduce the content of the fattiness, and accelerate the growth and development of animals, and so on. Growth hormone gene was used for the object of this research. The single nucleotide polymorphism (SNP) of growth hormone gene was investigated in various breeds of duck, including Beijing ducks, Xihu mallards, Cherry Valley Meat ducks, Jinding ducks, Shan Partridge ducks, Jingjiang ducks, Shaoxing ducks and Jinyun Partridge ducks. Twelve pairs of primers for coding and regulation regions, and intron 2,3 of GH gene were designed based on the database of duck genomic sequence(GenBank:AB158760)and the SNPs were detected by PCR-SSCP method. The objective of this research was to analyse the polymorphisms of GH, compared the frequency of genotypes, and probed into the relation of genotypes and breed traits of ducks, then provided the theory foundation for Marker-Assisted Selection in breeding for the future. The results are as the following:1. In 5′-UTR and 3′-UTR of growth hormone gene, two SNP were found among individuals: 230(C→G) and 244(C→A) in 5′-UTR. There was no SNP in 3′-UTR; it is that to say the 3′-UTR represented its own high conservativeness. The analytic results showed that: At loci of 5′-UTR, the sequence of 5′-UTR inclined to conservativeness of isozygoty in Beijing ducks, Xihu mallards, Cherry Valley Meat ducks, Shan Partridge ducks, and Jinyun Partridge ducks, and had a low variability in Shaoxing ducks and Jingjiang ducks, but had a high variability in Jinding ducks which reflected that Jinding ducks had own breed traits.2. In coding regions of growth hormone gene, only one SNP was found among individuals: 3701(C→T) in exon 4. However, the mutation at 3701 was a silence mutation. At loci of exon 4,the frequencies of genotypes in different breeds were significantly different, and the frequency of CC genotype in meat-type ducks were significantly higher than that in laying-type ducks,i.e., the C allele and D were the preponderant gene of meat-type ducks and laying-type ducks respectively. In addition, Beijing ducks and Cherry Valley Meat ducks with high C allele frequency were belong to meat-type ducks with high yield; Jinding ducks and Shaoxing ducks with high D allele frequency were belong to laying-type ducks with high yield.According to the results above, we can conclude that these SNPs may have relationship with some productive traits of ducks.3. In intron 2 and 3, eight SNP were found among individuals: 2593(C-T), 2770(G-A), 2813(T-A), 2829(C-A), 2894(C-T), 2896(T-C), 3100(C-G) in intron 2 and 3270(A-G) in intron 3. The analytic results showed that: All of the loci inclined to conservativeness of isozygoty in Shaoxing ducks, Beijing ducks and Cherry Valley Meat ducks (except the loci at 2593 in intron 2 for two of the latter), i.e., these breeds had their own conservativeness. But that of else breeds had abundant polymorphism, i. e., these breeds had their own variability. It is obvious that Beijing ducks, Cherry Valley Meat ducks and Shaoxing ducks had their own breed traits in variability of intron 2 and 3 of GH gene. Beijing ducks and Cherry Valley Meat ducks were belong to meat-type ducks with high yield; Shaoxing ducks was belong to laying-type ducks with high yield.According to the results above, we can conclude that these SNPs may have relationship with some productive traits of ducks.更多还原