Fig 5.

Phosphorylation regulates FOXC2 function in vivo. (A) Endothelial cell-specific gain-of-function models for the analysis of FOXC2 phosphorylation. (B) Both models express comparable levels of the transgene, as evidenced by RT-PCR analysis of the indicated mRNAs from E15.5 lungs. Transgene expression was initiated at E13.5. (C) Macroscopic appearances of FOXC2^ecGOF, pmFOXC2^ecGOF, and control E15.5 embryos. (D and E) FOXC2 overexpression does not affect capillary sprouting. (F) Overexpression of FOXC2 but not pmFOXC2 promotes vascular remodeling in maturing capillaries. Note the increased capillary branching and density in FOXC2^ecGOF embryos. Whole-mount staining of E15.5 head skin for pan-endothelial marker CD31 (green) and the transgene (red). The transgene expression was detected using anti-Myc antibody. Scale bars: 100 μm (D), 38 μm (E), 35 μm (F). (G) Quantification of vascular branching, density, and sprouting at the vascular front in the control, pmFOXC2e^cGOF, and FOXC2^ecGOF embryos. n = 3 per genotype. *, P < 0.05. n.s., nonsignificant.