猪Mu阿片受体基因外显子Ⅲ单核苷酸多态性

Single Nucleotide Polymorphism Analysis in Sow Mu Opioid Receptor Gene Exon Ⅲ

行为规癖 (古板行为 )是母猪一种常见的异常行为 ,表现为重复、不变化的行为模式 ,并且不带有明显的目的性。Mu阿片受体 (Muopioidreceptor,简称MOR)属于G蛋白偶联受体 ,分布在痛觉传导区以及与情绪和行为有关的区域 ,影响动物的神经反应和行为表现。本研究以Mu阿片受体基因作为候选基因 ,探讨影响母猪规癖性状的可能性。根据Mu阿片受体基因外显子Ⅲ的序列设计引物 ,用PCR -SSCP的方法对大白猪、长白猪和杜洛克猪进行单核苷酸多态性分析 ,发现该位点存在多态性。对两种纯合子片段克隆并测序表明 ,mRNA第 1169处存在C→T的单碱基突变 ,在第 12 2 6处存在C→A的单碱基突变 ,均为沉默突变。统计结果发现 3种基因型 (AA ,AB ,BB)在各品种中的分布不一致 ,χ2 独立性检验差异极显著 (P <0 0 1)。将大白猪 3种基因型同行为规癖性状进行最小二乘分析 ,结果表明 ,BB基因型与其他 2种基因型相比有较高的无食咀嚼表现频率 ,同AA型比较差异极显著 (P <0 0 1) ,咬栏和站立基因型间差异不显著。因此 。

Stereotypies are the most common abnormal behaviours in sows.Stereotypies are repeated,relatively invariable sequences of movements which have no obvious purpose.Mu opioid receptor is a member of G protein-coupled receptor family,distributed in the pain transduction region in the brain and related emotion and behavior regions where influence the animal neural reaction and behavior.The possibility of the MOR gene as the candidate gene to affect the stereotyped behavior traits in sows was discussed in this study.The primer of sow MOR gene exon Ⅲ partial sequence was designed to analyze single nucleotide polymorphisms by PCR-SSCP in Landrace,Yorkshire and Duroc breeds.Two polymorphisms were found,which was caused by a single nucleotide mutation of C to T and C to A at the positions of 1169 and 1226,respectively compared with the sequence in GenBank,but it was the silence mutation.The results of χ 2 test showed that the frequencies of genotypes resulted in different breeds were significantly different ( P <0 01).The least square analysis between the nucleotide acid mutant induced three genotypes and the stereotyped behavioral traits in Yorkshire showed that individuals with BB genotype have significant higher ( P <0 01) sham-chewing behavior than those with AA genotype,but not for bar-biting and standing.According to the above results,we can putatively draw the conclusion that MOR gene is probably the major gene affecting the sham-chewing behavioral traits or linked to the major gene.