BM morphology and microvessel density of Vegfa^δ/δ mice are normal while the endochondral ossification is decreased. (A) Representative histology images of mouse BM sections were captured from 1 WT mouse and 2 Vegfa^δ/δ mice in the trabecular area of distal femur samples at original magnification ×3, ×10, and ×40. Histologic specimens were stained with hematoxylin and eosin. Arrows indicate the epiphyseal growth plate. (B) BM sections were immunohistochemically stained with VWF to detect microvessels. Original magnification ×20. Red arrows indicate microvessels. (C) The average number of microvessels was counted in 3 different images per mouse captured from 2 mice per group. Bars represent mean ± SD. The thickness of the epiphyseal growth plate in femur was measured manually in 10× magnifications. Bars represent mean ± SD of 7-11 measurements from representative images, P < .0001, t test. All images were captured using a Zeiss slide scanner containing a Sony DFW-X710 camera and MIRAX software.