Effects Of Allium Mongolicum Regel Extracts On Expression And Methylation Of Genes Related To Fat Metabolism In Muscle Of Dorper×Thin-Tailed Han Crossbred Sheep

This paper is to investigate the effect of Allium mongolicum Regel and its extracts on dry matter intake,blood lipid parameters,lipid metabolism-related gene expression,methylation in longissimus dorsi muscle,and intramuscular fat of meat sheep.To explore the epigenetic mechanism in the process of regulation of fat deposition and fatty acid composition in mutton sheep by Allium mongolicum Regel and its extracts.Single factor complete random design was used in the current study.Sixty 4.5-month-old Dorper×thin-tailed Han crossbred ewes with similar body weight were assigned to four groups with 15 ewes in each group.Sheep in control group(T1 group)were fed a basal diet,and those in experimental groups were fed the basal diet supplemented with Allium mongolicum Regel powder(10 g/d each sheep)(T2 group),Allium mongolicum Regel water-soluble extract(3.2 g/d each sheep)(T3 group),Allium mongolicum Regel fat-soluble extract(2.8 g/d each sheep)(T4 group),respectively.The pre-trial lasted for 15 d,and the trial lasted for 60 d.The following three sections are included:Test 1 Effects of Allium mongolicum Regel extracts on lipid metabolism-related parameters in blood of Dorperxthin-tailed Han crossbred sheep.The preparation of Allium mongolicum Regel extracts was carried out firstly in the test.The intake situation was recorded during the feeding trial,Dry matter intake was calculated.From the day 1 to day 30 during the trial,the dry matter intake in T2 group was significantly lower than the other three groups(P<0.05).There were no significant differences among the other three groups(P>0.05).From the day 31 to day 60,There were no significant differences in the four groups(P>0.05).On day 60 in the trial,there were no significant differences in serum triglyceride(TG),total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),and high-density lipoprotein cholesterol(HDL-C)concentrations(P>0.05).Compared with the T1 group,the concentration of serum non-esterified fatty acids(NEFA)in the T3 group was significantly lower(P<0.05),and the serum NEFA concentration in the T2 and T4 groups was lower than that in the T1 group,but there was no significant difference(P>0.05).Test 2 Effects of Allium mongolicum Regel extracts on expression of genes related to fat metabolism in longissimus dorsi muscle of Dorperxthin-tailed Han crossbred sheep.After the trial,three sheep were randomly selected from each group and slaughtered to collect the longissimus dorsi muscle samples.The gene expression levels were determined by real-time quantitative polymerase chain reaction.Soybean extraction method was applied to measure the content of intramuscular fat.The results showed as follows:Compared with T1 group,the gene expression levels of ACACA,SCD in T2 group,T3 group,T4 group increased at different degrees.Among them:T3 group>T2 group>T4 group>T1 group.The expression levels of ACACA,SCD,SREBF1,FASN were significantly upregulated in T3 group compared with T1 group(P<0.05).The expression level of ACACA gene was significantly upregulated in T2 group compared with T1 group(P<0.05).The expression levels of ACACA,SREBF1,FASN genes were significantly upregulated in T3 group compared with T4 group(P<0.05).The content of IMF in T2 group was significantly higher than that in T1 group(P<0.05),and the T3 and T4 groups were higher than T1 group,but the difference was not significant(P>0.05).Test 3 Effects of Allium mongolicum Regel extracts on methylation of genes related to fat metabolism in longissimus dorsi muscle of Dorperxthin-tailed Han crossbred sheepThe CpG island methylation degrees of acetyl-CoA carboxylase(ACACA),Stearoyl-CoA desaturase(SCD),sterol regulatory element binding transcription factor 1(SREBF1),fatty acid synthase(FASN)genes from 2K upstream of transcriptional start site to 1K downstream of the first exon were measured according to methylation level sequencing of target region(second generation sequencing).A state of high demethylation was observed for each CpG island and site of ACACA,SCD,SREBF1,FASN genes,and no significant differences were found between four groups(P>0.05).Gene expressions were not associated with methylation degrees of CpG islands(P>0.05).In conclusion,Allium mongolicum Regel and its extracts can upregulate ACACA,SCD,SREBF1 gene expressions in longissimus dorsi muscle of Dorperxthin-tailed Han crossbred sheep,diet supplmented with Allium mongolicum Regel water-soluble extract has the largest range of up-regulation,followed by Allium mongolicum Regel powder,Allium mongolicum Regel fat-soluble extract is the lowest.And this up-regulation is not associated with DNA methylation modification of specific regions.