SNPS Detection Of LEP,LEPR,IGFs Genes In Luchuan And Large White Pig And Their Associations With Partial Production Traits

Using LEP,LEPR gene as the main effect candidate gene of litter size and growth traits, and using IGF-1,IGF-2 gene as the main effect candidate gene of growth traits in pigs , adopting PCR-SSCP to test single nucleotide polymorphisms(SNPs), the genetic variations of LEP,LEPR,IGF-1,IGF-2 genes were detected in Luchuan pigs(82 boars and 141 sows) and Large White pigs(37 boars and 44 sows), then the genotype frequencies and gene frequencies were counted. At the same time, the effects on litter size and growth traits of LEP,LEPR gene and the effects on growth traits of IGF-1,IGF-2 gene were estimated according to litter size datas of sows and growth datas of boars. The main results are showed as follows:1.Two alleles and three genotypes for LEP,LEPR,IGF-1,IGF-2 genes by PCR-SSCP were found in Luchuan and Large White pigs. The test of Hardy-Weinberg equilibrium showed that genotypic frequencies of LEP,IGF-1,IGF-2 genes were in equilibrium but genotypic frequencies of LEPR gene diverged from the genetic equilibrium (P<0.01) in Luchuan pigs and that genotypic frequencies of LEPR,IGF-1,IGF-2 gene diverged from the genetic equilibrium (P<0.01) other than genotypic frequencies of LEP gene in Large White pigs.2.LEP T3469C SNP had significant (P<0.05) effect on weaning weight (WW) and average daily gain (ADG) but no(P>0.05) significant effect on litter size in Luchuan and Large White pigs. LEP T3714G SNP had significant (P<0.05) effect on number born alive (NBA) of average of the 1st four parities and total number born(TNB) of first parity and average of the 1st four parities in Luchuan pigs, but had no( P>0.05) significant effect on litter size in Large White pigs.3.LEPR exon 2 polymorphisms had significant(P<0.05) effect on litter size of first parity and average of the 1st four parities in Luchuan pigs, and had significant( P<0.05) effect on litter size of first parity in Large White pigs, but had no( P>0.05) significant effect on growth traits in both porcine breeds.4.IGF-1 exon 3 polymorphisms had significant ( P<0.05) effect on WW and ADG, but had no ( P>0.05) significant effect on birth weight(WB) in both porcine breeds. 5.IGF-2 exon 2 polymorphisms had significant ( P<0.05) effect on WB,WW and ADG in Large White pigs, and had significant (P<0.05) effect on WB and ADG but no (P>0.05) significant effect on WW in Luchuan pigs.