MicroRNAs are a class of highly conserved and widely distributed non-coding RNAs. It is known that miR-26b has a high abundance in adipose tissue and is considered to be an effective regulator of adipogenesis. However, it is unclear whether miR-26b-5p, the product of miR-26b precursor, has the same effect as miR-26b. In the present study, we explored the potential role of miR-26b-5p in preadipocyte differentiation of goats. We found that the expression of miR-26b-5p had dramatic change during goat intramuscular preadipocyte differentiation. Transfection and RT-qPCR revealed that overexpression of miR-26b-5p increased the level of adipogenic marker genes and lipid accumulation in goat preadipocyte, suggesting that miR-26b-5p positively regulates goat preadipocyte differentiation. Furthermore, bioinformatics analysis and dual fluorescein reporter assays were performed to predict and validate the targets of miR-26b-5p. The results showed that miR-26b-5p has a binding site in the 3'UTR of FGF21 and overexpression of miR-26b-5p significantly down-regulated the expression of FGF21 mRNA. Luciferase activity assays confirmed that miR-26b-5p is a positive regulator of goat intramuscular preadipocyte via targeting FGF21. These findings provide reference for further revealing of the regulatory networks of goat fat metabolism and contribute to a better understanding of intramuscular fat deposition in goats.
Keywords: Differentiation; FGF21; Goat; Intramuscular fat; miR-26b-5p.