Effects Of Bta-miR-484 On Bovine Adipocyte Differentiation

The quality of beef has a direct impact on the economic value of beef,and intramuscular fat content is one of the important factors affecting the quality of beef.To explore the important regulatory factors of bovine fat production can improving the level of intramuscular fat deposition,and provide an important theoretical basis for meat quality.One of the hot spots in the study of gene expression regulation was miRNA,which is involved in many biological processes such as muscle development and fat formation in animals.In this study,RT-qPCR identification,cell differentiation induction,gene overexpression/silencing and other techniques were used to analyze the regulatory effect of miR-484 on the fat production of bovine.The main research results was as follows:(1)A total of 550 candidate target genes of bta-miR-484 were predicted by using bioinformatics software,and 11 genes that may have targeted binding relationship with bta-miR-484 were finally screened out.The dual luciferase activity report analysis showed that the candidate target genes NCOR1,IFITM1,HTT,HMGCR didn’t have targeted binding relationship with bta-miR-484.(2)The expression level of bta-miR-484 in the heart of bovine was significantly higher than that in other tissues(P<0.01);The expression level in muscle was significantly higher than that in back fat,spleen and liver(P<0.05),was significantly higher than that of kidney and lung(P<0.01);There was no significant difference in the expression levels in back fat,spleen and liver.The expression level was low in kidney and lung,and there was no significant difference between the two.(3)With the increase of the induction time of preadipocytes,the expression of bta-miR-484 was firstly increased and then decreased,and the expression of bta-miR-484 was higher than that of Od(P<0.01),and the expression level of bta-miR-484 on 4d was significantly higher than that on Od(P<0.01).(4)Compared with the control group,after overexpression of bta-miR-484,the lipid accumulation of bovine preadipocytes decreased(P<0.05),and the expression of adipogenic marker genes PPARy,C/EBPA and FABP4 decreased(P<0.05).After bta-miR-484 was inhibited,the lipid accumulation of bovine preadipocytes increased(P<0.05),and the expression of adipogenic marker genes PPARy,C/EBPA and FABP4 increased(P<0.05).In conclusion,the results of this study showed that NCOR1,IFITM1,HTT and HMGCR didn’t have targeted binding relationship with bta-miR-484.The expression of bta-miR-484 in adipose tissue was lower than that in heart and muscle,but higher than that in lung and kidney;and the expression of bta-miR-484 increased at first and then decreased during adipogenic differentiation.Overexpression of bta-miR-484 inhibited lipid accumulation in bovine preadipocytes,and inhibition of bta-miR-484 promoted lipid accumulation in bovine preadipocytes.The results suggest that bta-miR-484 negatively regulates the differentiation of adipocytes,and provide a basis for further exploration of the mechanism of bta-miR-484 regulating bovine fat deposition.