MicroRNA 143‐5p regulates alpaca melanocyte migration, proliferation and melanogenesis

Abstract microRNAs (miRNAs) have been shown to be closely involved in the control of melanogenesis and hair colour in mammals. Previous data also indicate that miR‐143 regulates cell growth in melanoma. Here, we aimed to investigate the role of miR‐143‐5p in alpaca melanocytes. We found that miR‐143‐5p was highly expressed in the cytoplasm of alpaca melanocytes as demonstrated by an in situ hybridization assay. Prediction analysis revealed that miR‐143‐5p could regulate TGF‐β‐activated kinase 1 (TAK1) expression, which we confirmed by luciferase reporter assay, indicating that miR‐143‐5p controls TAK1 expression by directly targeting its 3′ untranslated region (UTR). miR‐143‐5p overexpression decreased TAK1 expression, which led to increased melanocyte migration and proliferation, and downregulation of microphthalmia‐associated transcription factor (MITF), which regulates melanin production. These results support a functional role for miR‐143‐5p in regulating alpaca melanocyte migration, proliferation and melanogenesis through direct targeting of TAK1.