Fig. 9. Epithelial-derived laminin α5 is involved in hair germ–dermal papilla anchoring.

a Immunofluorescence labelling of laminin α5, COL13A1 and integrin β1 in the hair germ (HG)–dermal papilla (DP) interface region of different hair cycle stages of dorsal HFs. To avoid possible imaging interference from melanin deposition, C57BL/6 albino mice were used. Open arrowheads and arrows indicate the signals of laminin α5, COL13A1 and integrin β1 in the interface basement membranes (BMs) and the hook BM regions, respectively. b Immunofluorescence images of perlecan (green) and DAPI counterstain (blue) merged with bright field images of the HG–DP interface region of telogen phase HFs of control (K5Cre⁺;Lama5^fl/+) and K5Cre⁺;Lama5^fl/− mice. Dark melanin pigments are visible. Open arrowheads indicate a gap between the HG and DP. c Quantification of DP volume in control (K5Cre⁺;Lama5^fl/+) and K5Cre⁺;Lama5^fl/− mice. DP volume was three-dimensionally quantified using images taken in (b) and visualized by violin plot. Most of the DPs with a small volume (<2000 μm³) are detached from the HG or dispersed. The middle line in the grey box indicates the mean, the lower and upper hinges correspond to the SD. n = 40 HFs from two mice. Scale bars: 20 μm (a, b).