Phenotype of Col2-DKO mice.

(A) Representative photograph of Control pups and Col2-DKO littermates at E18.5, P7, and P14. Scale bar: 1 cm. (B) Body weight of Control (E18.5; n = 16, P7; n = 4, P14; n = 4) and Col2-DKO (E18.5; n = 12, P7; n = 4, P14; n = 4) mice at various stages. *P < 0.05, **P < 0.01. (C) Humeral and tibial bone length at E18.5 of Control (n = 6) and Col2-DKO (n = 7) mice. (D) Quantitative analysis of t1 and t2 transcripts in the knee cartilage of WT (n = 3) and Col2-DKO (n = 3) mice at E18.5 using real-time RT-PCR. The expression of each transcript was normalized to that of β-actin. **P < 0.01.