Reduced expression of chondrocyte hypertrophy–related genes on Smad4 mutant mice.
A–D, immunostaining of Runx2 on the forelimb sections from the control (A and C) and mutant (B and D) embryos at E12.5. E–P, RNA in situ hybridization staining of Ihh, Runx3, and Sp7 on forelimb sections from control (E, G, I, K, M, and O) and mutant (F, H, J, L, N, and P) embryos at E12.5 and E13.5. Arrows in A–P indicate protein or RNA expression in humerus. Q, Runx2, Runx3, Ihh, and Sp7 RNA expression levels were determined by qRT-PCR at E12.5 and E13.5 in the forelimbs. n = 3, *, p < 0.05.