FIGURE 3

Interaction between mesenchymal cells and actinotrichia in vitro.(A–D) The morphology of primary cultured mesenchymal cells at day 2 after culture on a Matrigel-coated dish. Mesenchymal cells and actinotrichia were isolated from TG larval fins [TG; 5^xand1(MC]: Lifeact-mCherry/5^xand1(2P): And1^full-GFP). (A) In the condition without actinotrichia, mesenchymal cells showed the symmetric morphology. (B–D) In the condition with actinotrichia, mesenchymal cells elongated along a single actinotrichia (B), two actinotrichia (C) and multiple actinotrichia (D). (E) Cell aspect ratio of mesenchymal cells. Mesenchymal cells in contact with actinotrichia had a more elongated shape compared to the cells not in contact with actinotrichia. (F–G′) SEM images of cultured mesenchymal cells holding the actinotrichia on a Matrigel-coated dish. The actinotrichia was surrounded with the plasma membrane of the mesenchymal cell (F) and partially embedded inside the mesenchymal cell (G). The magnified images in white box are shown. P-values: ***P < 0.0001. AT, actinotrichia. Scale bars: 20 μm in (A–D), 10 μm in (F,G), 1 μm in (F′,G′).