Fig. 1.

Survival curve, spina bifida and lung phenotype of Pdgfc^−/−; Pdgfra^GFP/+ mice. (A) Kaplan–Meier curve showing survival of Pdgfc^−/−; Pdgfra^GFP/+ pups and their littermates. Based on 47 Pdgfc^−/−; Pdgfra^GFP/+ pups. (B) Newborn Pdgfc^−/−; Pdgfra^GFP/+ mouse with haemorrhage over the dorsal back of the spine indicating a severe spina bifida. (C) Spina bifida after removal of the skin at P3. (D) Transverse section through the spina bifida area at P1, showing the presence of skin covering the affected area (arrow). s.c., spinal cord; v.b., vertebral body. (E) Alcian Blue/Alizarin Red staining of spinal column at P0, wild type (wt) (left) and Pdgfc^−/−; Pdgfra^GFP/+ (right). Arrow marks an unfused vertebral arch. (F) Freely dissected lumbar vertebrae at P20, stained with Alcian Blue/Alizarin Red, wt (left) and Pdgfc^−/−; Pdgfra^GFP/+ (right). (G) Paraffin section of P19 lung from Pdgfc^+/−; Pdgfra^GFP/+ (left) and Pdgfc^−/−; Pdgfra^GFP/+ (right). Note the absence of secondary alveolar septa in the mutant lung. Scale bar: 100 µm. (H) Quantification and comparison of perimeter of open areas in paraffin sectioned lungs. Open areas in Pdgfc^−/− mice were significantly larger than Pdgfc^+/+ control mice, both in absence and presence of Pdgfra^GFP/+. *P<0.05, **P<0.01.