A Novel <scp>lncRNA</scp> ‐ <scp>ADAT1</scp> / <scp>miR</scp> ‐449a‐5p/ <scp>FZD5</scp> Axis Regulates Melanogenesis and Proliferation in Goat Melanocytes

Long noncoding RNAs (lncRNAs) regulate diverse biological processes. However, their roles in melanogenesis remain poorly understood. This study investigated a lncRNA (ENSCHIT00000005207; lncRNA-ADAT1) that is differentially expressed in the skin of white and brown goats. lncRNA-ADAT1 expression in goat melanocytes was determined using quantitative real-time polymerase chain reaction (qRT-PCR) and in situ hybridization. LncRNA-ADAT1 interference and overexpression vectors were designed, synthesized, and transfected into melanocytes. Target miRNAs of lncRNA-ADAT1 were predicted using bioinformatics tools, and their interactions were validated through luciferase reporter assays. MiRNA expression vectors were constructed and transfected into melanocytes, and the targeted regulatory gene was identified using a luciferase assay. The effects of target gene on melanogenesis and cell proliferation were investigated. qRT-PCR results revealed distinct expression patterns of lncRNA-ADAT1 in male and female goat tissues, whereas in situ hybridization assays showed that lncRNA-ADAT1 was abundantly expressed in melanocyte cytoplasm but minimally expressed in the nucleus. LncRNA-ADAT1 overexpression in melanocytes significantly increased (p < 0.01) melanogenesis and cell proliferation by interacting with miR-449a-5p as a competing endogenous RNA (ceRNA). MiR-449a-5p overexpression in melanocytes significantly inhibited (p < 0.01) melanin production and significantly promoted cell proliferation (p < 0.05). Furthermore, FZD5 had miR-449a-5p binding sites, and miR-449a-5p overexpression significantly reduced FZD5 expression (p < 0.001). Transfection of melanocytes with the FZD5 confirmed that FZD5 significantly increased (p < 0.01) melanin production and (p < 0.05) melanocyte proliferation by regulating β-Catenin expression. lncRNA-ADAT1 promoted melanogenesis and cell proliferation in goat melanocytes via the miR-449a-5p/FZD5/β-Catenin axis.