Differential Expression of miR-202 and Validation of Predicted Target Genes in the Skin Tissue of C57BL/6 Black Mice and BALB/c White Mice.

In recent years, with the need of the fur industry to obtain greater quantities of high-quality fur and the research of hair follicle development attracting greater attention, the role of miRNAs in hair follicle development has become a field of intense interest. miRNAs are short length RNAs that affect gene regulation by binding to the 3'-untranslated region (3'UTR) of the mRNAs of certain target genes. This study predicted and validated the target genes of miR-202 in the skin tissue of C57BL/6 black mice and BALB/c white mice. The expression of miR-202 target genes (wnt5a, kit, and tcf7) was examined by real-time quantitative polymerase chain reaction and western blot in the mouse skin tissue and human embryonic kidney 293T cells (HEK293T cells) which overexpress miR-202. The luciferase reporter gene system was used to verify the correlation between the expression of miR-202 and its putative target genes. We show that the expression of miR-202 was higher in the skin tissue of C57BL/6 black mice than in the skin tissue of BALB/c white mice (p < 0.05). Furthermore, the expression of wnt5a, kit, and tcf7 was observed to be negatively correlated with the expression of miR-202 and to be downregulated by miR-202 in vitro and in vivo. The luciferase reporter gene system indicated that the target sequences of miR-202 are present in 3'UTR of wnt5a, kit, and tcf7 mRNAs. Altogether, this study has shown that the expression of miR-202 was different in the skin tissue of C57BL/6 black mice and BALB/c white mice and that wnt5a, kit, and tcf7 are negatively regulated by miR-202.