鸡OBR基因第20外显子多态性与脂肪性状的相关研究

对鸡OBR基因的单链构象多态性进行检测,在第20 外显子发现了一个新的单核苷酸多态位点。克隆测序了2种纯合子片段,在第20外显子编码区的860位碱基确认了一个由T变为C的突变,编码的氨基酸由缬氨酸突变为丙氨酸。在一个地方鸡杂交群体中检验这一多态位点与脂肪性状的相关,建立固定效应模型进行最小二乘分析,对脂肪性状的不同基因型效应进行差异显著性检验。结果表明:试验群体中AA、AB、BB基因型频率分别为0.641、0.292和0.067。不同基因型对各组杂交肉鸡腹脂率、皮下脂肪厚、肌间脂宽和肌内脂肪含量的效应均不显著(P>0.05),说明这一外显子片段上的变异位点并不是导致脂肪性状产生差异的原因。此结果为进一步研究鸡OBR基因多态性及其功能提供参考,并为丰富基因图谱的标记提供理论依据。

Studies on Single Nucleotide Polymorphism of OBR-exon 20 and Its Associations with Fattiness Traits in Chicken

OBR (obese receptor) gene plays an important role in leptin functioning signal transduction. The polymorphism of the OBR-exon 20 was detected, and a novel SNP was found by the technique of single strand conformation polymorphism (SSCP) and finally confirmed by sequencing. The frequencies of different genotypes in cross combinations of local chickens were calculated and the relationship between three genotypes and fattiness traits of these chickens were analyzed based on liner model. The results showed that the novel SNP was at 860th locus (T/C) in OBR-exon 20, genotype frequencies of AA, AB, BB were 0.641, 0.292 and 0.067, respectively, in trial group. The effect of various genotypes on abdominal fat percentage, subcutaneous fat thickness, intramuscular fat width and intramuscular fat percentage were not significant (P>0.05). It could be a reference for future research on polymorphism of OBR and supply more information for gene mapping.