3个鸡种A-FABP基因单核苷酸多态性的研究

Research on Single Nucleotide Polymorphism of Adipocyte Fatty Acid Binding Protein Gene in Three Chicken Breeds

利用PCR-RFLP技术(限制性内切酶为Taq )检测尤溪麻鸡、鹿苑鸡、隐性白羽鸡3个鸡种的脂肪细胞型脂肪酸结合蛋白(A-FABP)基因第1和第3外显子的单核苷酸多态性(SNP)。结果表明:在该位点上,3个鸡种的A-FABP基因均存在SNP,外来品种隐性白羽鸡以杂合子Cc居多,地方鸡种以cc居多,3个鸡种均含有较高频率的等位基因c,其中以尤溪麻鸡最高,而以隐性白羽鸡最低;对第3外显子扩增片段(375bp)进行回收测序,发现在第3外显子1805位存在SNP,尤溪麻鸡与鹿苑鸡C突变为T的频率(分别为0.7344、0.7188)明显高于隐性白羽鸡C突变为T的频率(0.5156)。A-FABP第1外显子(85位点)的SNP不影响A-FABP的氨基酸序列变化,而第3外显子(1805位点)的SNP影响A-FABP的氨基酸序列变化,由脯氨酸转变为丝氨酸,说明该多态性可能通过A-FABP基因表达水平而影响鸡的肉质。

The single nucleotide polymorphism of adipocyte fatty acid binding protein (A-FABP) gene on the sequence sites of the first exron in 96 chicken including Youxima chicken, Luyuan chicken and Recessive White-feather chicken were detected by PCR-RFLP. The results showed as follows: All these chicken breeds had SNP in A-FABP gene on site 85. Recessive White-feather chicken presented mostly Cc genotype while other two breeds presented mostly cc genotype. The allele c had high frequency in three chicken breeds with Youxima chicken having the highest and Recessive White-feather chicken having the lowest. After the product of PCR (375 bp) were cloned and sequenced, all these chicken breeds had SNP in A-FABP gene on site 1()805. The frequency of substitution of C→T in Youxima (chicken,) Luyuan chicken (0.734()4, 0.718()8 respectively) is significantly higher than that of Recessive White-feather chicken ((0.515()6).) The genetic variation on 85 site had no effect on amino acid sequence of A-FABP and 1()805 site had effect on amino acid sequence of A-FABP: Pro→Ser which suggested that the chicken quality may have relation to A-FABP′s expression possibly controlled by genetic variation.