Fig. 5.

Fgfbp1 is essential for collagen IV deposition to the vascular basement membrane. (A-P) Analysis of BM composition in cortices of WT and Fgfbp1^iEC-KO pups at P7 (A,B,E,F,I,J,M,N) and P21 (C,D,G,H,K,L,O,P). Sections (100 µm thick) were stained for CD31 (white; E-H,M-P) to identify blood vessels, collagen IV (green, A-H) and laminin α2 (red, I-P). Yellow arrowheads indicate vessels positive for both collagen IV and laminin α2. White arrows indicate vessels positive for laminin α2 and negative for collagen IV. (Q-R) Quantification of collagen IV (Q) and laminin α2 vessel coverage in the cortex of WT and Fgfbp1^iEC-KO P7, P14 and P21 pups. Each dot represents the average of at least three confocal acquisitions from a single animal. Data are mean±s.e.m. **P<0.005, ***P<0.0005; Student's t-test. Collagen IV coverage is reduced in cortical vessels of Fgfbp1^iEC-KO. (S) Dotted bar graphs of the fold change in expression of Col4a1, Col4a2 and Lama2 mRNAs in ECs freshly isolated from the brains of WT and Fgfbp1^iEC-KO P7 and P21 pups. Each dot represents a single animal. Data are mean±s.e.m. There is no difference in either genotype by Student's t-test. Scale bar: 50 µm.