(A) H&E staining and in situ hybridization of Col10a1, Col1a1, Mmp13, Mmp14 in Mmp14ΔHC and control mice at P10. White signals marks mRNA expression of corresponding genes. HZ, hypertrophic zone; TB, trabecular region. Scale bar, 50um(B) Edu labeling assay in Mmp14ΔHC and control mice. Hypertrophic chondrocytes (HC) descendants, nucleus, and proliferating cells were labeled with RFP (red), DAPI (blue), and Edu (green). (C) Tartrate-resistant acid phosphatase (TRAP) staining comparing Mmp14ΔHC and control mice. Black arrows mark TRAP+ cells. HZ, hypertrophic zone; TB, trabecular bone. Counting of TRAP+ cells suggests the number of osteoclasts are not significantly affected in the mutants (n = 6 for control, n = 4 for Mmp14ΔHC mutants). (D) Immunofluorescence staining of RFP, Perilipin, GFP, and DAPI labeling tdTomato (red), adipocytes (white), osteoblasts (green), and nucleus at P10. Quantitation of RFP+ PER+ , RFP-PER+, and PER+ cells at distal tibia comparing Mmp14ΔHC mutants and control at P10. Unpaired Student’s t-test are used for PER+ RFP and PER+ RFP+ and cells. Quantitation is shown in (n = 5) (p<0.05).