Analysis of the vasculature in WT and in VE-cadherin-Cre × RFP mice. (A) Immunofluorescent staining of blood (MECA-32, green) and lymphatic (LYVE-1, red) vessels in ear skin whole mount. Scale bar: 100 μm. (B) Mice with fluorescent BVs and LVs were generated by breeding VE-cadherin-Cre mice with Rosa26-loxP-stop-loxP-tdRFP mice. Cre-mediated deletion of the floxed stop-site induced transcription of tdRFP in VE-cadherin–expressing cells. (C-E) Analysis of ear whole mounts from the offspring, so-called VE-cadherin-Cre × RFP mice. (C) Co-staining for LYVE-1 (green), confirming RFP expression in both BVs and LVs. First row: Scale bar: 150 μm. Second row: high magnifications of white inserts. Scale bar: 50 μm. (D) High magnification view of an RFP-positive LV in an ear whole mount reveals a valve structure, as indicated by a white arrow. The large arrowhead shows a typical blind beginning of an initial LV. Scale bar: 50 μm. (E) RFP is expressed in the cytosol and in the nucleus, as evidenced by costaining for DAPI. Scale bar: 50 μm. Gamma corrections were applied to (A-C; only red channel) and (D-E) to enhance visibility of LVs.