Effect of endogenous VEGF and FGF2 sequestering by specific antibodies on UB growth under RA conditions. UBs were stained using FITC-conjugated DBA. Metanephroi were freshly dissected from 12-day embryos (A), cultured for two days under RA in control media (B, control) or control media containing either 1 µg/ml αmVEGF (C), 25 µg/ml αhFGF2 (D), or a combination of the two (E). (F) Quantitative analysis of UB branching. (G) Protein content of metanephroi. Data shown in A–E are representative. Data shown in (F and G) are means ± SEM of four independent experiments. *p < 0.05 versus control, **p < 0.01 versus control.