Fig. 4. Loss of heparin/neuropilin-binding VEGF isoforms, but not loss of SEMA3A, impairs brain vascularisation. Visualisation (A-F) and quantitation (G) of vessel branching in the subventricular zone of 12.5 dpc mouse hindbrains. PECAM-positive vessels are shown in a 0.25 mm² area of littermate hindbrains with normal (Vegfa^+/+) or reduced (Vegfa^+/120 and Vegfa^120/120) levels of heparin/neuropilin-binding VEGF isoforms (A-C), or in littermate hindbrains expressing (Sema3a^+/+) or lacking (Sema3a^+/-and Sema3a^-/-) SEMA3A (D-F). (G) Quantitation of vessel branching in hindbrains lacking heparin/neuropilin-binding VEGF isoforms or SEMA3A in a CD1 or C57Bl/6 background. Wild types (Vegfa^+/+ or Sema3a^+/+), dark grey; heterozygous mutants (Vegfa^+/120 or Sema3a^+/-), light grey; homozygous mutants (Vegfa^120/120 or Sema3a^-/-), white. LOF, loss of function.