Polymorphisms And Expression Of LDLR Gene In Anhui Native Pig Breeds And Its Association With Serum Lipid Traits

In this study,using 4 Anhui pig breeds(Wei,Anqing six-end-white,Wannan black and Huo Shou black)as experimental material,Low-density lipid protein receptor(LDLR)gene is selected as a candidate gene which plays an important role in the process of cholesterol metabolism.Using PCR-SSCP Technique to detect LDLR gene segments of genetic variation,the correlation between the genetic variation and the correlation with blood lipid traits was detected by the method of least square analysis of SPSS program.And the genetic effects of mutant sites on the expression of LDLR gene in muscle and liver tissue were detected;the effect of LDLR gene expression in liver and dorsal muscle tissue of the longest muscle tissue of the liver and the back of the body was detected by bivariate correlation analysis.Studying the correlation between the structure,heredity,variation and expression of blood lipid traits related functional genes and their correlation with related traits,choose a a new molecular marker polymorphism sites and to investigate the gene as a molecular marker using on the feasibility of pig genetics and breeding,and provides a scientific basis for genetic improvement of blood lipid and meat quality traits in Anhui local pig breeds.The results are as follows:(1)The expression of LDLR gene in different tissues showed the highest expression of LDLR in the liver,the lowest expression in the spleen.The expression of the high-to-low expression in the tissues is liver,back,back,heart,kidney,brain,lung and spleen.The results confirmed the high expression of LDLR gene in the liver,which provided the scientific basis for the follow-up experiment.(2)There was a A?G mutation in intron 4 and a C?T mutation in intron 4 at12088 bp and 12093 bp detected by PCR-SSCP in Wei pig,Anqing six white,Wannan black pig and Huoshou black pig.Three genotypes(AA/AG/GG)and(CC/CT/TT)based on the LDLR intron 4 mutation were found.According to the results of ?2 test,the locus is in Hardy-Weinberg equilibrium in the population.g.12088 A > G and g.12093 C > T is a linkage mutation site.(3)Correlation analysis between g.12088 A > G/ g.12093 C > T mutation site and blood cholesterol content showed that the mutation in this site had a significant effect on total cholesterol and low density lipoprotein cholesterol(P < 0.05).The polymorphism in intron 4 has a certain effect on the serum lipid levels,but it is still necessary to take a further study as an important genetic marker.(4)The expression of LDLR gene in liver and muscle of different genotypes showed that different genotypes of Wei pig in the liver has significant difference,LDLR mRNA in AA/CC genotype was significantly higher than that of GG/TT genotype(P < 0.05);LDLR mRNA in muscle expressed the same trend,there is no significant difference.(5)LDLR gene expression and meat quality traits correlation analysis showed that: in the liver,LDLR gene expression and stearic acid content was significantly positive correlation(P < 0.05),and back-fat thickness was significantly negatively correlated;in the muscle,LDLR gene expression and back fat,back fat thickness muscle cholesterol intramuscular fat,palmitoleic acid and oleic acid was significant positive correlation,with stearic acid and linoleic acid showed a significant negative correlation(P < 0.05).Results suggest that LDLR g.12088 A > G/g.12093 C > T sites can be applied as a genetic markers for the improvement of serum lipid traits in Wei pigs,and that LDLR may play an important role in the forming progress of porcine serum lipid traits,carcass traits and meat quality traits.