Profiling of Differential Expressed MicroRNA in Intramuscular Fat and Subcutaneous Fat of Simmental and Bioinformatic Analyses of miR-27b Target Gene

【Objective】 In order to explore the role of microRNA in the growth and development process and its regulatory mechanism in intramuscular fat, the profiling of differential expressed microRNA in intramuscular fat and subcutaneous fat of Simmental were analyzed by microarray and real-time PCR(qRT-PCR). The target genes and signal pathway of miRNA-27b were predicted by bioinformatics software and database.【Method】Microarray of bovine microRNA was employed to detect the differentially expressed microRNA between intramuscular adipose tissue and subcutaneous adipose tissue. Then the expression of four selected microRNAs(miR-140, miR-145, miR-143 and miR-27b) in intramuscular adipose and subcutaneous adipose was also validated by qRT-PCR method. Target scan algorithm was used to predict target gene of miR-27b, and the result of gene set was analyzed by bioinformatics of GO annotations, GO term enrichment and KEGG enrichment methods. 【Result】 It was revealed that there were 88 microRNAs with significant differential expression between bovine intramuscular fat and subcutaneous fat(P0.01).The expression of miR-140, miR-145, miR-143 and miR-27b which were also detected by qRT-PCR was in high concordance with microarray results. The results of bioinformatics indicated that target genes of miR-27b were mostly enrichment in MAPK, Wnt,Hedgehog, TGF-beta, GnRH signaling pathway, especially in MAPK pathway. 【Conclusion】There are specific microRNA expression profiles in bovine intramuscular adipose tissue and subcutaneous adipose tissue. Some differentially high expressed microRNA in intramuscular adipose tissue such as miR-27b may play important roles by distinct pathway in bovine intramuscular adipogenesis.