Photomicrographs of bone from oim/oim mice after cell infusions. Mice were infused with either NABMC or MSCs from wild-type mice and then the bones were immunostained with a polyclonal antibody which recognizes only the proα2 polypeptide (not proα1) and visualized with NOVARed. The positive control (top left panel) is normal mouse bone which demonstrates staining of the trabecular bone but not the growth-plate cartilage on the right side of the section. The negative control (top right panel) is oim/oim mouse bone, which does not express proα2 peptide. Oim/oim mice infused with NABMC (bottom left panel) show red stain (proα2 expression) in the trabecular bone but not the articular cartilage on the left side of the section. Oim/oim mice infused with MSCs (bottom right panel) lack any red staining indicating the lack of detectable proα2. Original magnification, ×200.