The Analysis Of Molecular Marker Affecting Porcine Gestation Length Based QTL

The economic efficiency of swine industry is very important. It is influenced by thegestation length deeply. According to QTL mapping results, pig and human comparativemap and physiological or biochemical functions of genes, three candidate genes wereselected: HSD11B1 (11βhydroxysteroid dehydrogenase-1), PGHS2 (prostaglandin Hsynthase-2), MyoG (myogenin). These genes were isolated and identified withcomparative genomics and bioinformatic approaches, etc. Qingping, New Qingping line,Landrace, Large White, Duroc, Chinese lean type new line Dâ…£V₁, Dâ…£₂ were used in thisstudy. The relationship of the polymorphism of the genes and association studies of thegene polymorphism with reproduction traits were investigated. The main results are asfollowing:1. The analysis results of genetic effect of HSD11B1geneThe partial genomic sequence HSD11B1gene of Qingping, New Qingping line, LargeWhite, Duroc pig breeds were obtained. Comparative sequencing of these four breedamplified fragments revealed 22 single nucleotide polymorphisms (SNPs), an PCR-Bsh1236â… -RFLP was developed to detect G/A transition.For PCR-Bsh1236â… -RFLP, The frequency of the B allele in Qingping, New Qingpingline is higher than in others during 7 different breeds and lines. The result of x² showedthat there was significant difference between Qingping and other groups.Qingping, New Qingping line, Landrace, Large White, Chinese lean type new lineDâ…£₁, Dâ…£₂ were genotyped for population variation investigation and associationanalysis with gestation length. Results showed that the gestation length of genotype BB isless than genotype AA. There was significant difference between genotype AA and BBwith gestation length of first parity in Chinese lean type new line Dâ…£₁ breed (P＜0.05),the additive effect is significant (P＜0.05).2. The analysis results of genetic effect of Myo G geneQingping, New Qingping line, Landrace, Large White, Duroc, Chinese lean type newline Dâ…£₁, Dâ…£₂ were used to study allele frequencies. The Qingping is all genotype MM,but the duroc is almost genotype NN. The result of x² showed that there was significantdifference between Qingping and other groups.New Qingping line, Landrace, Large White, Duroc, Chinese lean type new line Dâ…£₁,Dâ…£₂ were genotyped for population variation investigation and association analysis with gestation length. Results showed that the gestation length of genotype MM is less thangenotype NN. There was significant difference between genotype AA and BB withgestation length of multiple parity in Landrace (P＜0.01), the additive effect is significant(P＜0.01).New Qingping line, Landrace, Large White, Duroc, Chinese lean type new line Dâ…£₁,Dâ…£₂ were genotyped for population variation investigation and association analysis withlitter size. Results showed that the litter size of genotype MM is less than genotype NN.But there were no significant difference in lines. (P＞0.05)3. The analysis results of genetic effect of PGHS2geneThe partial genomic sequence HSD11B1gene of Qingping, New Qingping line, LargeWhite, Duroc pig breeds were obtained. Comparative sequencing of these four breedamplified fragments revealed there was a single nucleotide polymorphism (SNP) in exon8. an PCR-SSCP was developed to detect A/G transition.For PCR-SSCP, The frequency of the B allele in Qingping, New Qingping line ishigher than in others during 7 different breeds and lines. The result of x² showed thatthere was significant difference between New Qingping and other groups.Qingping, New Qingping line, Landrace, Large White, Duroc were genotyped forpopulation variation investigation and association analysis with gestation length. Resultsshowed that the gestation length of genotype BB is less than genotype AA. There wassignificant difference between genotype AA and BB with gestation length of multipleparity in Qingping breed (P＜0.05), the additive effect is significant (P＜0.05).