Fig. 3. Double immunostaining for endogenous Plcg2 gene-driven EGFP and cell markers. EGFP (green), cell markers (red) and DAPI (blue) staining are shown. (A) Transverse sections of Plcg2^EGFP/EGFP E14.5 embryos. Arrows indicate EGFP⁺ F4/80⁺ monocytes. (B) Transverse sections of Plcg2^EGFP/EGFP E13.5 embryos. V, cardinal vein; L, lymph sac. Arrows indicate EGFP⁺ platelets lack nuclei. Arrowhead indicate venous EGFP⁺ ECs. (C) Transverse sections of Plcg2^EGFP/EGFP E14.5 embryos. Arrows indicate a subpopulation of EGFP⁺ ECs. (D) Transverse sections of thoracic walls of E15.5 embryos. Arrows indicate lymphatic vessels; arrowhead indicates Lyve-1⁺ EGFP⁺ monocytes. EGFP⁺ ECs were not LECs. Scale bars: 50 µm in A-D. (E) Transverse sections of E13.5 embryos. A, carotid artery; V, cardinal vein; L, jugular lymph sac. Panels c and d are higher magnification images for a and b, respectively. Arrows indicate EGFP⁺ non-ECs. Arrowhead indicates a venous EC. Scale bars: 200 µm in a,b; 50 µm in c,d.