文昌鸡GHR基因，ESR基因和IGF-Ⅰ基因与产蛋性能的相关性研究

【作者】 葛洪伟；

【导师】 李碧春；

【作者基本信息】 扬州大学 ， 动物遗传育种与繁殖， 2007， 硕士

【摘要】 文昌鸡产自海南省文昌市,是海南省地方优良肉鸡品种,传统名牌产品,以其优良的肉质风味荣居海南“四大名菜”之首,在我国及东南亚国家均享有美誉,是海南饮食文化不可缺少的部分。本实验以文昌鸡作为试验样本,采用候选基因法,以GHR （intron 2、intron 5）、ESR462、ESR465、IGF-I五个基因座位作为候选基因,采用PCR-RFLP和PCR-SSCP方法对其进行了多态性分析。1.首次在文昌鸡中检测了与产蛋性能相关的五个候选基因座位的多态性。在这五个基因位点中,处于Hardy-Wenberg平衡状态的有两个,分别是ESR462 （5’ flanking region）、IGF （5′UTR）、非Hardy-Wenberg平衡状态的有三个:GHR442 （intron 2）、GHR436 （intron 5）、ESR465 （5’ flanking region）。其中ESR465 （5’ flanking region）位点未发现多态。2.初步确定了1个新的与鸡产蛋性能相关的分子标记,该标记位于ESR基因5’调控区域,对两种纯合基因型的片段进行回收、克隆、测序比较发现,ESR基因5’侧翼序列片段中第580位核苷酸AATA缺失,因而造成该基因5’侧翼序列的多态性。3.确定了2个与鸡产蛋性能相关的分子标记: ESR基因5’调控区域的SSCP位点、IGF-I基因5’非编码区域PstI酶切位点。4.对基因型与所检测个体相应的产蛋性能采用GLM分析进行遗传效应研究,结果表明:IGF-I基因对300日龄产蛋数有显著影响（加性作用）,IGF-I ^H2H2个体300日龄产蛋数与400日龄产蛋数分别比IGF-I^H1H1型个体高7.77% （P<0.05）和7.84% （P<0.05）;IGF-I ^H2H2个体300日龄产蛋数比IGF-I H1H2型个体高7.34% （P<0.05）;IGF-I ^H2H2个体平均连产天数分别比IGF-I^H1H1型个体和IGF-I H1H2型个体长0.42天（P<0.05）和0.60天（P<0.05）。结果显示,IGF-I基因以加性作用,其中300日龄产蛋数加性效应值为0.199 （P<0.05）。5.筛选出较优的分子标记:进行多个分子标记效应比较研究,确定了有利于产蛋性能提高和不利于产蛋性能提高的分子标记: ESR酶切基因位点基因型F₁F₃（88.59,134.95）、IGF-I酶切位点基因型H₂H₂（89.03,137.84）的300日龄、400日龄产蛋数都比较高,另外需要指出的是,ESR酶切基因位点基因型F₁F₃和IGF-I酶切位点基因型H₂H₂的平均连产天数分别达到3.56d、3.38d,显著高于其它基因型个体。更多还原

【Abstract】 Egg production 120 hens from a pureline of Wenchang layers （Chinese indigenous chicken breed） were collected in testing center of poultry quality, Ministry Agriculture of China. Data on egg production including total egg production, continual egg-laying, and number of double-yolked eggs were collected daily using trap nests to identify individual Wenchang chicken. The data for individual hen were collated over a 5-month period and recording commenced at 25 weeks of age and all birds were treated the same.A candidate gene approach was used to determine whether specific loci explain responses in the egg production traits of Wenchang chicken in its pure-line population. PCR-RFLP and PCR-SSCP techniques were conducted on candidate genes that were Growth hormone recepto（rGHR）、Estrogen Receptor （ESR）、insulin-like growth factor-1（IGF-I）respectively. This study was designed to identify the polymorphisms of each gene locus and found genetic effects on the traits. The results is as following.Polymorphic sites were found in each genes andχ² analysis among these gene locus indicated that only the frequencies of ESR、IGF-I fit Hardy-Weinberg equilibrium. It suggested that allele and genotypes frequencies of these sites were stable. In addition,association analysis of the these gene polymorphism with egg production was conducted in Wenchang chicken, Two genetic molecular markers of egg production in Wenchang chicken were primarily confirmed which were 5’ flanking region of ESR and 5′UTR of IGF-I.The results with GLM analysis showed that such significant effects of genes’marker as followsESR polymorphism has significant effect on egg production trait and average days of continual egg-laying （ADCE）. The ESR F₁F₃ genotype had more eggs （300d） at 88.59 compared to 80.43 for F₂F₂ （P<0.05）. The ESR F₁F₃ genotype had longer ADCE at 3.56 compared to 2.38 for F₂F₂ （P<0.01）. IGF-I polymorphism has additive effect on egg production trait, also has dominant effect on eggshell weight and eggshell stress, The IGF-I PstI H₂H₂ genotype had greater number eggs （300d） at 89.03 compared to 82.61 for PstI H₁H₁ （P<0.05） and PstI H₂H₂ genotype also had greater number eggs （400d） at 137.84 compared to 127.82 for PstI H₁H₁ （P<0.05）. The IGF-I PstI H₂H₂ genotype had longer ADCE at 3.38 compared to 2.96、2.78 for PstI H₁H₁ and H1H2 （P<0.05） .GHR polymorphism has additive effect on number of double-yolked eggs （DYE）, The GHR HindIII C₁C₁ genotype had greater DYE at 1.00 compared to 0.30 for HindIII C2C2 （P<0.05）.更多还原