Association Study For Polymorphism And Expression Of FTO Gene With Meat Quality Traits In Qianbei Brown Goat

In order to explore the correlation between FTO gene polymorphism and serum lipid metabolism related indicators in Qianbei Brown goats and the correlation between FTO gene and protein expression and meat quality traits of different ages,the age of 4 months~2 years old goat is the target of the study,using the direct sequencing technology of PCR products to screen FTO genes,and the correlation analysis with the measured indicators of serum lipid metabolism,and the determination of 4 months old,1.5 years old,2.5 years old.The meat quality traits of Qianbei Brown goats were analyzed by correlation analysis between FTO gene and protein expression detected by real-time PCR and Western blotting,and the genetic markers related to serum lipid metabolism,especially those with fat deposition,were obtained.To compare the expression of FTO gene and its protein in different age groups and its correlation with meat quality traits,to provide a reference for revealing the genetic effects of FTO gene on Qianbei Brown goats and regulating the molecular mechanism of fat metabolism.The basis for the selection of the fine meat quality traits and the establishment of the molecular marker database of Qianbei Brown goats.The experimental results are as follows:1.Screening,bioinformatics and genetic specificity analysis of FTO gene SNPs in Qianbei Brown goatsA total of 9 SNPs were found in exon 2,3 and 9 and some introns of FTO gene of Qianbei Brown goats by DNA direct sequencing.Bioinformatics analysis showed that the FTO protein has a low complexity region,a NTD catalytic domain,no transmembrane structure,and 7 Ser,5 Thr,and 5 Tyr may become phosphorylation sites.The four mutations in exon 3 are located in the NTD catalytic domain of the FTO protein,and the variation in the g.T125417C,g.T125300A site causes a change in the secondary structure of the mRNA.The sequencing results showed that there were three genotypes in each mutation site.The analysis of genetic traits indicated that each mutation site belonged to moderate polymorphism(0.25<PIC<0.5)and did not deviate from the Hardy-Weinberg equilibrium state.Reasonable genetic information.The haplotype and linkage disequilibrium analysis showed that there were 22 haplotypes in the population,7 of which had higher frequency,and the r~2values of 4 sites of g.T125300A,g.C125357T,g.G125405T and g.T125417C were all greater than 0.33.There is a strong genetic linkage disequilibrium effect.g.T426229C,g.C426244G,g.G426347A The r~2between the three loci were 1.000,0.738,and 0.738,respectively,indicating that there is also a strong genetic linkage disequilibrium effect.2.Correlation analysis between FTO gene polymorphism and serum lipid metabolismCorrelation analysis was performed between the 9 SNPs screened by FTO gene of Qianbei Brown goats and the measured serum lipid metabolism indices.A total of 3loci were correlated with serum lipid metabolism indicators.Among them,there were2 sites at 4 months of age:the levels of serum ADP and LEP in different genotypes of g.T125300A were significantly different(P<0.05),and the levels of serum ADP in g.G125405T were significantly different(P<0.05).The difference in LEP content was extremely significant(P<0.01);there were 3 sites in the adult of 2 years old in Qianbei Brown goats:g.T125300A,g.G426347A,different genotypes,serum AST and ALT content were significantly different(P<0.01),there were significant differences in serum AST and ALT levels between different genotypes of g.G125405T(P<0.05),and serum HSL levels were significantly different between genotypes of g.G426347A(P<0.05).Three sites with significant correlation with serum lipid metabolism index in adult goats aged 2 years old were combined and analyzed for correlation with serum lipid metabolism indices.It was found that homozygous TTGGGG is the dominant combination genotype for regulating fat deposition Qianbei Brown goats.3.Study on meat quality traits of Qianbei Brown GoatsAccording to the characteristics of the growth and development of the Qianbei Brown goats,combined with the current domestic and foreign fat lamb production characteristics and local slaughter habits,the 4 months,1.5 years,and 2.5 years of the Qianbei Brown Goat were selected for meat quality traits determination.The results showed that the intramuscular crude fat,crude protein content,cooked meat rate,shearing force and water loss rate increased with age,and the intramuscular crude fat content was significantly different between the three age groups(P<0.01).The crude protein content of 2.5-year-old Qianbei Brown goat was significantly different from that of 1.5 years and 4 months(P<0.01).Based on the measured meat quality indicators,the crude fat and crude protein content of the 2.5-year-old Qianbei Brown goatswas higher than that of 1.5-year-old and 4 months old.4.Correlation analysis between FTO gene and important tissue protein expression and meat quality traits in Qianbei Brown goatsReal-time quantitative PCR was used to detect the difference in expression of FTO gene in heart,liver,spleen,lung,kidney,thymus,abdominal fat,hypothalamus and longissimus dorsi muscle of 4 months old,1.5 years old and 2.5 years old.It was found that the FTO gene was different in different tissues of different ages.Among them,the expression of FTO mRNA of the 4-month-old Qianbei Brown goat was hypothalamus>liver>abdominalfat>heart>kidney>lung>spleen>thymus>dorsal longissimus;FTO mRNA expression of 1.5-year-old Qianbei Brown Goat was liver>spleen>Thymus>hypothalamus>abdominalfat>kidney>lung>heart>dorsal longissimusdorsi;2.5-year-oldFTOmRNAexpressionof spleen>thymus>hypothalam>abdominal fat>liver>kidney>heart>lung>longest back muscle.At the same time,the three most important tissues(hepatic,dorsal longissimus and abdominal fat)with body fat synthesis,storage,decomposition and deposition were selected.The FTO protein expression was detected by Werstern blot.The results showed that the 4th-month-old Qianbei Brown Goats FTO Protein liver>abdominal fat>dorsal longissimus,1.5-year-old abdominal fat>liver>dorsal longissimus;2.5-year-old liver>abdominal fat>dorsal longissimus.Correlation analysis with meat quality traits showed that the correlation between FTO mRNA and protein expression and meat quality traits in different parts was different at different ages.The overall trend was:the correlation between FTO mRNA and protein expression at 4 months and 1.5 years and meat quality index is stronger than 2.5 years old.