Macrophage and erythroid cell apoptosis in FL after Vegfc deletion at E7.5. (A-B) Flow cytometric analysis of annexin V and propidium iodide–stained E14.5 Vc^iΔR26 FL cells. As the pie diagrams illustrate, 28.5% of the total FL cells are apoptotic; ∼90% of these are Ter-119⁺, ∼10% are F4/80⁺ macrophages (n = 6; mean ± SEM). (C) Immunohistochemical staining shows that at E14.5, Vc^iΔR26 FLs have significantly less F4/80⁺ macrophages, and many of these are apoptotic based on staining for activated caspase-3 (n = 3 per group; mean ± SEM; *P < .05). Bar represents 100 μm. (D-E) qPCR analysis on Maea, Itga4, and Vcam1 RNAs from Ter-119⁺ (erythroid enriched) and F4/80⁺ (macrophage enriched) FL cells. Quantifications of RNA fold changes are shown (n = 3-5 per group; mean ± SEM; *P < .05; ***P < .001).