Correlation Analysis Of The Genes Related With Reproductive,Growth And Meat Quality Traits In Pigs

Compared with traditional breeding techniques,MAS can achieve early and accurate seed selection in breeding.Therefore,the purpose of our study was to select reliable molecular markers for breeding.This study is divided into two parts.In the first part,we use the technology of molecular markers-PCR-RFLP to analyze five candidate genes(Hal,GH,AREG,ESR,BF)in purebred sows of Yorkshire,Landrace and Duroc.Find the polymorphism loci of these genes and do correlation analysis with growth and reproduction traits.The purpose is to provide certain and scientific basis for the research of improving the growth and reproduction performance of pigs.In the second part,we chose Laiwu pigs and DLY(Duroc * Landrace * Yorkshire)as the research objects.In this study,we selects 30 genes associated with intramuscular fat deposition to explore the key genes which can influence porcine meat quality for molecular markers and provide a theoretical basis for the further cultivating commercial pigs of high meat quality.The results are as follows:(1)The polymorphisms of Hal,GH,AREG,ESR and BF genes were detected by PCR-RFLP method,analyzing for their association analysis with some economic traits(Including total number born,number born alive,birth weight,backfat and reached 100 kg days).400 breeding sows including Yorkshire,Landrace and Duroc of three pig breeds was collected.The results showed that the polymorphic sites of five genes were found in all populations tested of three breeds.The genotype distribution,however,revealed great differences among different breeds.The genotype distribution of each group reached the H-W equilibrium in addition to Hal in Landrace and ESR in Duroc,respectively.The preponderant alleles of five gene in all herd were A.(2)The Hal,GH,AREG,ESR and BF genes can affect the reproductive traits of purebred sows.In Yorkshire,for Hal gene,AA genotypic gilts produced 1.9 total number born(TNB)and 2.72 number born alive(NBA)(P<0.05)more than AB genotypic gilts,respectively.For ESR gene,AB genotypic gilts produced 1.58 TNB and 1.11 NBA(P<0.05)more than BB genotypic gilts,respectively.AA and AB genotypic sows produced 1.39 TNB,1.48 NBA and 1.43 TNB,1.62 NBA(P<0.05)more than BB genotypic gilts,respectively.For BF gene,AA and AB genotypic gifts produced 1.47 NBA and 1.99 NBA(P<0.05)more than BB genotypic gilts,respectively.In Landrace,for AREG gene,the average birth weight of AA genotypic sows were more 0.19 kg(P<0.05)than BB genotypic sows.In Duroc,for AREG gene,AA and AB genotypic gifts produced 1.39 and 1.48 TNB(P<0.05)more than BB genotypic gifts,respectively.AA and AB genotypic sows produced 1.1 NBA and 1.21 NBA(P<0.05)more than BB genotypic gifts,respectively.(3)The Hal,GH and AREG genes can affect the growth traits of purebred sows.In Yorkshire,for Hal gene,the reached 100 kg days of AA genotypic gilts were more 16.48 days(P<0.05)than the AB genotypic gilts.For AREG gene,the live backfat of BB and AB genotypic sows was more 0.82 mm and 0.77 mm(P<0.05)than AA genotypic sows,respectively.In Landrace,for GH gene,the hundreds of kilograms of day age of AA and AB genotypic gilts were more 8.81 and 12.03 days(P<0.05)than the BB genotypic gilts,respectively.(4)The association analysis between the gene and meat quality traits in Laiwu pigs and DLY pigs showed that the expression of lipid metabolism related gene mRNA was associated with the deposition of intramuscular fat.In addition,through stepwise multiple regression analysis,it was found that there were 4 independent variables with significant difference(P<0.05).The 4 differentially expressed genes(CPT1B,FASN,SLC27A1 and FABP3)were found to have an effect on the content of intramuscular fat by a factor of 38%.At the same time,comparative study of Laiwu and DLY pigs showed that LIPE gene may be an important genetic marker predicting the fat deposition of pigs,SREBF1 may be a candidate gene of fat synthesis,and CPT1 B gene can be used as a genetic marker to predict intramuscular fat content.The results showed that Hal,GH and AREG genes had effects on reproductive performance and growth performance of pigs.ESR gene and BF gene had a major effect on reproductive performance of sows.It can be used in breeding to improve the growth and reproduction performance.Meanwhile,LIPE,SREBF1 and CPT1 B genes can be used forgenetic markers to improve pork quality.The results of this study provide basic information for molecular marker assisted selection breeding.