松辽黑猪IGF-Ⅰ基因外显子4多态性及与部分生产性能的关系

以IGF-Ⅰ基因作为松辽黑猪生长和胴体性状的候选基因，采用PCR-SSCP方法检测30头松辽黑猪IGF-Ⅰ基因外显子4(179 bp)的多态性，对该基因的不同基因型与生长和胴体性状的关系进行分析。结果表明，IGF-Ⅰ基因的2个等位基因和3种基因型在松辽黑猪中均有不同频率的分布，遗传多态性较高; IGF-Ⅰ不同基因型对断奶后日增重有显著影响，AA型显著高于AB型和BB型(P<0.01)。AA型猪的瘦肉率显著低于AB型和BB型(P<0.01)，而AA型猪的平均背膘厚显著高于AB型和BB型(P<0.01)，对其它性状的影响差异不显著。因此，IGF-Ⅰ基因的遗传分析结果说明该基因对松辽黑猪的平均日增重、瘦肉率和平均背膘厚等3个性状有显著的遗传影响，可以初步推断IGF-Ⅰ基因可能是影响猪生长和胴体性状的一个主效基因或是一个与影响猪生长和胴体性状的QTL连锁的基因。

The Exon4 Polymorphism of IGF- I Gene and Its Relationship with Partial Performances in Songliao Black Swine

IGF-Ⅰ gene was chosen as a candidate gene for growth and carcass traits of songliao black swine.The exon4(179bp) polymorphism of IGF-Ⅰ gene was detected by PCR-SSCP in 30 pigs,and the relationship between the polymorphism and growth and carcass traits was analyzed.The results showed that 2 alleles and 3 genotypes of IGF-Ⅰ gene were detected in songliao black swine,there was a higher degree of polymorphism; different IGF-Ⅰ genotypes significantly affected average daily gain after weaning.Average daily gain after weaning for AA genotype on IGF-Ⅰ was significantly higher than for AB and BB. The pigs with AA genotype had a lower lean percentage than those with AB genotype and BB genotype(P<0.01), and had a higher average backfat thickness than those with AB genotype and BB genotype(P<0.01). Other traits were not significantly affected.Therefore,the genetic analysis of IGF-Ⅰ gene revealed that IGF-Ⅰ locus significantly affected average daily gain after weaning, lean percentage,and average backfat thickness,it could be preliminarily deduced that IGF-Ⅰ gene was probably a major gene or a QTL linked gene which associated with growth and carcass traits.