Five consecutive sections were probed by immunohistochemistry for type 2 collagen (Col2), type 10 collagen (Col10), Ihh, osteocalcin (OC) and Osx in the epiphyses of vehicle treated Tshr+/−, Tshr−/− and TH treated Tshr−/− mice at day 7, 10 and 14. Chondrogenic cells (CC), the secondary ossification center (SOC) and bone in the epiphyses of the tibias are labeled. Arrows in red indicate OC-positive and Osx-positive cells.