Association Analysis Of LPL Gene Polymorphism And Meat Quality Traits Of Northeast Mutton Sheep

In the experiment, LPL gene is considered to be candidate gene affecting meat quality traits of northeast mutton sheep. Mainly study the SNPs of exon and the association between SNPs and meat quality traits. The experiment results would provide the molecular biological basis to meat improvement and genetic breeding of mutton sheep.Muscle tissues from 48 healthy older northeast mutton sheep were collected to extract total RNA and genomic DNA. The sequence of LPL gene cDNA in northeast mutton sheep was cloned by using RT-PCR method and original TA cloning kit, and analysis of bioinformatics was implemented. LPL gene is considered to be candidate gene affecting meat quality traits. Sequencing and PCR-RFLP method were employed to find SNPs in some exon of LPL gene. Association analysis between LPL gene polymorphisms and meat quality traits was studyed by the general linear model. The main experiment results were as follows:1. Total RNA was extracted and the sequence of LPL gene c DNA in northeast mutton sheep was cloned by using RT-PCR method. Then sequencing the sequence. analysis of bioinformatics was implemented. Analysis of bioinformatics was implemented and the results showed that the complete open reading frame size of LPL gene in northeast mutton sheep was 1 437 bp and encoding 478 amino acids.2. Sequencing and PCR-RFLP method were employed to find SNPs in exon3, exon4, exon5 and exon6 of LPL gene. The results showed that SNPs in exon3(T304C, A384T) and exon4(T462C) were detected. But there is no SNPs in exon5 and exon6. The amino acid sequences of these 3 SNPs are identical. They are all silent mutations.3. Enzyme digestion and genotyping method were used to SNP of exon3(A384T) in LPL gene. The statistical analysis of data of gene frequency, the genotype frequency, χ2-Hardy-Weinberg equilibrium, homozygosity(Ho), heterozygosity(He), effective number of alleles(Ne) and polymorphism information contents(PIC) showed that the PIC was low polymorphism(PIC<0.25) and the colony has reached Hardy-Weinberg equilibrium(P>0.05).4. The result of association analysis between the polymorphism of exon3(A384T) in LPL gene and meat quality traits showed that the drip loss of TT genotype is very significantly higher than TA, AA genotype(P<0.01); the p H1 of TT genotype is significantly higher than TA genotype(P<0.05) and no significant difference between TT genotype and AA genotyp(P>0.05); no significant difference of press loss, cooking percentage and shear force between different genotypes was found(P>0.05). The myristic acid of TT genotype is significantly lower than TA, AA genotype(P<0.05); the palm acid of TT genotype is significantly lower than TA genotype(P<0.05) and no significant difference between TT genotype and AA genotyp; no significant difference of other fatty acids between different genotypes was found(P>0.05). The glycine of TT genotype is significantly higher than TA genotype(P<0.05) and no significant difference between TT genotype and AA genotyp; the arginine of TT genotype is significantly higher than TA, AA genotype(P<0.05); no significant difference of other amino acids between different genotypes was found(P>0.05).