[P2-3-17] Spatiotemporal expression profiles of Wnt5a ligand and Frizzled receptor proteins in developing tongue muscles of fetal mice
Keywords:tongue muscle development、Wnt5a and Frizzled receptor、spatiotemporal expression
The Wnt5a ligand regulates muscle development via selective binding to and activation of Frizzled (Fzd) receptors which drive noncanonical Wnt signaling pathways. However, information about the spatiotemporal expression of these proteins during muscle development is insufficient, impairing the elucidation of molecular mechanisms of it. In this study, we analyzed the spatiotemporal expression profiles of the Wnt5a, Fzd2 and Fzd5 in the developing tongue muscles of fetal mice from embryonic day 12.5-18.5 using immunofluorescence (IF) double staining of a target protein and desmin, a myogenic marker protein. When needed, IF images were subjected to digital detection analysis using the WinROOF 2018 ver. 4.19.0 image processing software. Here we show that Wnt5a expression was detected both in the desmin-positive immature muscle cells and the desmin-negative subepithelial mesenchyme cells, whereas Fzd2 expression was selective for desmin-positive immature muscle cells. Mature myofibers equipped with sarcomere structures did not express Wnt5a or Fzd2. In contrast, Fzd5 was expressed predominantly in desmin-negative subepithelial mesenchyme cells at any embryonic stage examined. These results suggest that Wnt5a signaling plays distinct roles in different tissues, and Wnt5a-Fzd2 signaling may participate in the process of differentiation and maturation of tongue muscle fibers.