鸡瘦蛋白受体(OBR)基因内含子8单核苷酸多态性与体脂性状的相关研究

以东北农业大学高低脂双向选择系的第 6世代肉鸡为材料 ,鸡 7周龄时测定体重和腹脂重等屠体性状。根据鸡瘦蛋白受体基因内含子 8的序列 (GenBank登陆号 :AF2 2 2 783 )设计引物 ,用直接测序的方法检测多态性位点 ,用PCR SSCP的方法进行基因型分析 ,建立适合的统计模型对多态性位点产生的基因型与生长和体组成性状进行相关分析。结果表明 ,在第 50 0和 659位碱基同时发生了T—C、G—A突变。经最小二乘分析 ,3种基因型在腹脂重和腹脂率上差异显著 (P <0 0 5) ,BB型个体腹脂重和腹脂率显著高于AB型 (P <0 0 5) ,极显著地高于AA型个体 (P <0 0 1) ;3种基因型在肝重上差异显著 (P <0 0 5) ,且AA基因型个体的肝重显著低于AB和BB基因型个体。初步推断OBR基因可能是影响鸡脂肪性状的主效基因或与主效基因连锁 ,推测可以利用这个多态位点对鸡的体脂性状进行标记辅助选择

Correlation Analysis Between Single Nucleotide Polymorphism of the Leptin Receptor Intron 8 and Fatness Traits in Chickens

Leptin receptor plays an important role in leptin functioning signal transduction and it may have direct effects on the deposition of adipose tissues and the body weight,the leptin receptor (OBR) gene,therefore,can be considered as a candidate gene in the study of fat deposition of the chicken.The function of OBR gene has been intensively studied in mammals,but study of OBR gene in the chicken is still rare.In this paper,the NEAU divergent selection broiler lines for abdominal fat were used.Body weight and fatness traits were measured in the sixth generation broiler population of the two lines at 7 week of age.Two pairs of primers for intron 8 of OBR gene were designed according to the database of chicken genomic sequence (Accession No.AF222783).The SNP was detected by DNA sequencing,and PCR-SSCP method was then developed to screen the population.The correlation analysis between the polymorphisms of the intron 8 of OBR gene and growth and fatness traits in the population was carried out using the appropriate statistical model.Two SNPs were found in the population.Those were T500C and G659A.The least square analysis showed that BB genotype birds had significant higher (P<0.05) abdominal fat weight and percentage of abdominal fat than AA and AB genotype birds,and AA genotype birds had significant lower (P<0.05) weights of livers than AB and BB genotype birds at the same time.From these results we can putatively drew the conclusion that OBR gene may be a major gene to affect the fatness traits or linked to the major gene,and the two polymorphisms found in OBR gene intron 8 region could be used to select the chicken for low abdominal fat in molecular marker-assisted selection programs.