Yap and pYap expression during limb development. Consecutive histological sections from hindlimbs of mouse embryos at E13.5 (A), E14.5 (B) and E16.0 (C) were immunohistochemically stained for Yap or pYap, or stained with an immunoglobulin G (IgG) isotype control antibody, and counterstained with haematoxylin. Results shown are representative of data from three embryos at each time point. Boxed area on left shows approximate location of higher magnification images on right. P: perichondrium, C: cartilage anlage. HC: hypertrophic cartilage. Bars indicate 100 μm (tile scan images on left; 20× objective) and 10 μm (higher magnification images on right; 100× oil objective). Images on far right are representative isotype controls for Yap (A, C) and pYap (B). pYap, phosphorylated Yap; Yap, Yes-associated protein.