Molecular Regulation of Yak Preadipocyte Differentiation and Proliferation by LncFAM200B and ceRNA Regulatory Network Analysis

The positive regulatory role of lncFAM200B in differentiation and lipid deposition in yak intramuscular preadipocytes has been demonstrated in our previous study. However, the regulatory mechanisms remain unclear. In this study, we aimed to produce complete mRNA and microRNA (miRNA) profiles after adenovirus-mediated lncFAM200B overexpression in yak preadipocytes using high-throughput sequencing. We constructed a competing endogenous RNA (ceRNA) network with lncFAM200B as the core and identified the functions of the selected target miRNA during cell proliferation and differentiation. We obtained 118 differentially expressed genes (DEGs) after lncFAM200B overexpression, 76 of which were up-regulated, including Notch signaling members NOTCH3, DTX3L, and HES4, and 42 DEGs were down-regulated, including genes related to the cell cycle (CCNA2, BUB1, CDC20, TOP2A, and KIF20A). Additionally, many ubiquitin-mediated proteolysis pathway members were also significantly up-regulated (BUA7, PML, TRIM21, and TRIM25). MiRNA sequencing showed that 13 miRNAs were significantly up-regulated, and 12 miRNAs were down-regulated. Among them, 29 targets of 10 differentially expressed miRNAs (DEMs) were differentially expressed, including miR-152-FBXO33, miR-6529a-TRIM21, miR-148c-NOTCH3, and the miR-6529b-HES4 axis. We further verified that overexpression and inhibition of miR-6529a can inhibit and promote, respectively, the proliferation and differentiation of preadipocytes. Taken together, our study not only revealed the regulatory network of lncFAM200B during yak preadipocytes differentiation but also laid a foundation for elucidating the cause for lower intramuscular fat content in yaks at the molecular level.