Fig. 4

Postnatal deletion of Col2⁺ cells causes mouse growth retardation and a type II collagenopathy phenotype. a, b Quantitative analysis of the body length and tail length of Col2-creERT and Col2-creERT;DTA^+/+ mice from P3 to four weeks of age (n = 6 mice per condition; three independent experiments). The data are presented as the means ± s.ds. c Macroscopic image of 4-week-old littermates. The mutant (right) mouse is small and exhibits dwarfism. d Total view of Col2-creERT and Col2-creERT;DTA^+/+ mice double stained with Alizarin red and Alcian blue at four weeks of age. e X-ray of 4-week-old Col2-creERT and Col2-creERT;DTA^+/+ mice. f Representative picture of the microCT 3D structure of the femur head of 4-week-old Col2-creERT and Col2-creERT;DTA^+/+ mice. g Quantitative analysis of the BV/TV, Both, Tb.N, and Tb.Sp of the femurs of 4-week-old Col2-creERT (CreERT) and Col2-creERT;DTA^+/+ (DTA) mice (n = 5 mice per group). The data are presented as the means ± s.ds. h Total view of the lower extremities of Col2-creERT and Col2-creERT;DTA^+/+ mice double stained with Alizarin red and Alcian blue at four weeks of age. Yellow arrow, delayed secondary ossification development in Col2-cre;DTA^+/− mice. i Quantitative analysis of the femur length and tibia length of 4-week-old Col2-creERT (CreERT) and Col2-creERT;DTA^+/+ (DTA) mice (n = 6 mice per condition; three independent experiments). The data are presented as the means ± s.ds. j Total view of the skulls of Col2-creERT and Col2-creERT;DTA^+/+ mice stained with Alizarin red and Alcian blue at four weeks of age. k Total view of the forelimb of Col2-creERT and Col2-creERT;DTA^+/+ mice stained with Alizarin red and Alcian blue at four weeks of age. l Safranin O/Fast Green staining of coronal sections of the femurs of 4-week-old Col2-creERT and Col2-creERT;DTA^+/+ mice. m High-magnification image showing secondary ossification and cartilage in the femurs of 4-week-old Col2-creERT and Col2-creERT;DTA^+/+ mice. n High-magnification picture showing the chondrocyte morphology of 4-week-old Col2-creERT and Col2-creERT;DTA^+/+ mice. o Immunofluorescence staining of the GP and AC of 4-week-old Col2-creERT and Col2-creERT;DTA^+/+ mice for type 2 collagen. p High-magnification image showing type 2 collagen staining in 4-week-old Col2-creERT and Col2-creERT;DTA^+/+ mice. q Phalloidin staining showing the cartilage cytoskeleton of 4-week-old Col2-creERT and Col2-creERT;DTA^+/+ mice. r Quantitative measurements of the percentage of cells with intact actin fragments relative to the total cells in Col2-creERT (CreERT) and Col2-creERT;DTA^+/+ (DTA) mice (n = 6 mice per condition; three independent experiments). The data are presented as the means ± s.ds. The statistical significance was determined by one-way ANOVA and Student’s t test. *P < 0.05, **P < 0.01, ***P < 0.000 1, NS not statistically significant