Characterization of dermal lymphatic LYVE-1⁺ capillaries and LYVE-1⁻ collectors. (A–F) Mouse ear skin whole-mounts were analyzed by immunofluorescence to validate the suitability of LYVE-1 as a marker for differentiating between lymphatic capillaries and collectors. In contrast to dermal lymphatic LYVE-1⁻ collectors, dermal lymphatic LYVE-1⁺ capillaries are characterized by VE-cadherin⁺ button-like cell–cell junctions (A and B), the absence of smooth muscle cell coverage (C and D), and a thin BM (E and F). Scale bars in A–C and E, 50 µm. Representative images from three to five experiments are shown. Quantifications of αSMA (D) and laminin (n = pooled whole-mount data from 3–5 mice per condition; G). (G and H) Presence of αSMA-covered collectors in human skin. Immunofluorescence staining for αSMA, podoplanin (podo), LYVE-1, and Hoechst was performed in healthy human skin. The yellow box in G highlights the enlarged region shown in H. Orange arrow, podo⁺ LYVE-1⁺ αSMA⁻ capillary; yellow arrow, podo⁺ LYVE-1⁻ αSMA⁺ collector. Scale bars, 100 µm (overview) and 50 µm (zoomed-in image). Images obtained in one out of three different skin biopsies analyzed are shown. (D and F) Unpaired Mann–Whitney test. ****, P < 0.0001.