Genetic Variation Of Lipid Metabolism Related Genes In Beef Cattle And Their Association With Meat Quality Traits In Yanbian Cattle

In this study,four groups of beef in a total of 356 individuals,including Luxi Cattle,Nanyang Cattle,YanHuang Cattle and Yanbian Cattle,were used as research object.The SNPs of MC4R,LEPR,HSL,LPL and SCD candidate genes which influence fat metabolism of cattle were measured by sequences analysis technology combine with bioinformatics methods to explore the genetic structure and genetic diversity of experimental cattle.Meanwhile,the correlation analysis of the meat quality traits of 157 Yanbian Cattle in these sites were conducted,in order to screen out functional genes or molecular markers that significantly affecting meat quality traits.The research aim to provide the genetic basis for the preservation and utilization of beef cattle germplasm resources and efficient breeding of Yanbian Cattle.The results were as follows:1.Seven mutations were found in HSL gene,and the mutations of 1208bp,1537bp,1574bp,1729bp,1740bp,1869bp,and 1921bp in four experimental cattle groups were all intermediate polymorphism and low polymorphism.Among of them,the mutation of 1729bpA?G led to the encoded protein amino acid from glutamine mutated to arginine.The mutation of 1740bpT?C led to serine mutated into proline.The mutation of 1869bpA?G led to valine mutated into isoleucine.The mutation of 1921 bpA?G led to glutamate mutated into lysine.The correlation analysis of Yanbian Cattle meat quality traits showed that,1208bp A?C site significantly associated with eye muscle area,water-holding capacity,brightness,nutmeg acid,oleic acid,linoleic acid,linolenic acid,serine,glycine,alanine,isoleucine,leucine and lysine.1537bp A?C site significantly correlated with cooking loss,dripping loss and yellowness.1729bp A?G site significantly correlated with slaughter weight,carcass weight,backfat thickness,myristic acid,palmitic acid,linoleic acid,serine,arginine,and lysine.1921 bp A?G site significantly correlated with slaughter weight,carcass weight,nutmeg acid,linoleic acid,linolenic acid,serine,glycine,alanine,isoleucine,leucine,proline,and lysine.2.The mutation of LPL gene 329bp A?T in the Yanbian Cattle group was intermediate polymorphism,while the other groups were low polymorphism,which resulted in the threonine mutated into serine.329bp A?T site significantly correlated with eye muscle area,cooking loss,dripping loss,PH,myristic acid,linoleic acid,serine,glycine,alanine,and lysine.3.The mutation of LEPR gene 2831bp C?T in four experimental cattle groups were all intermediate polymorphism,which caused threonine mutated into methionine.The mutation also caused change in hydrophobic structure,which resulted ina helix lost and ? fold increase at the 940th site of protein secondary structure.It also resulted in the space position change of a helix and ? corner in protein tertiary structure.The correlation analysis indicated that the site significantly correlated with backfat thickness,eye muscle area,and cooking loss of Yanbian Cattle.4.The mutation of MC4R gene 1069bp C?G in four experimental cattle groups were all intermediate polymorphism,which caused leucine mutated into valine.The mutation also caused change in hydrophobic structure,which resulted in a helix lost and ? fold increase at the 166th,243th and 281th site of secondary protein structure.It also resulted in the space position change of ? corner in protein tertiary structure.The correlation analysis indicated that the site significantly correlated with backfat thickness,brightness,yellowness,myristic acid,linoleic acid and linolenic acid of Yanbian Cattle.5.Three mutations were found in SCD gene,which were all intermediate polymorphism in four experimental cattle groups.Among of them,the mutation of 1022bp caused encoded protein amino acid from alanine mutated to valine,which resulted in hydrophobic structure change.It showed that the hydrophobicity of valine encoded protein was higher than alanine encoded protein.It also caused protein sencondary structure appeareda helix lost at the 291th,random coil and ? fold lost at the 289th,but no changes in protein tertiary structure.The correlation analysis indicated that the mutation of 846bp A?G significantly correlated with slaughter weight,carcass weight,backfat thickness,stearic acid,linoleic acid,aspartic acid,glutamic acid,glycine,and alanine content of Yanbian Cattle.And the mutation of 1022bp C?T significantly correlated with the content of sspartic acid,tyrosine,and stearic acid.