Fig. 5

Spatial distribution of embryonic and postnatal Col2⁺ cells in mouse long bones and knee. a Representative images from the lineage tracing of embryonic Col2⁺ cells in long bones and knee joints at different time points (P0, P8, P14, P30, P90, P180 and P365). b Representative images from the lineage tracing of postnatal Col2⁺ cells in long bones and knee joints at different time points (P6, P8, P14, P30, P90, P180 and P365). This analysis was performed by injecting 75 mg·kg⁻¹ tamoxifen into P3 mice. To better present the data, the information for the Col2-creERT;tdTomato mice in each figure is presented as the harvest time (tamoxifen injection date + tracing time period)., e.g., P6 (3 + 3) means that the harvest date of Col2-creERT;tdTomato mice is P6, that tamoxifen was injected at P3 and that tracing was performed for three days. Because all Col2⁺ cells were activated starting from the embryonic stage in Col2-cre;tdTomato mice, we included only the date for the harvesting of mouse samples. For example, P8 means that the harvest date for the Col2-cre;tdTomato mice was P8. c Representative images from the lineage tracing of postnatal Col2⁺ cells in long bones and knee joints activated at different time points (P3, P21, P27, P87, and P362). Tamoxifen (75 mg·kg⁻¹) was injected into mice at the indicated time points. d Representative images from the lineage tracing of Col2⁺ cells in long bones and knee joints at P90 after activation at different time points (embryonic stage, P3, P30, P60 and P87). e Representative images from the lineage tracing of Col2⁺ cells in the long bones and knee joints of mice at P30 after activation at the indicated time points (embryonic stage, P3, and P60). This analysis was performed by the injection of 75 mg·kg⁻¹ tamoxifen into Col2-creERT;tdTomato mice at different time points. f Representative images of the long bones and knee joint of Col2-creERT;tdTomato mice at P30. This analysis was performed by the injection of 75 mg·kg⁻¹ vehicle into Col2-creERT;tdTomato mice at P3. g Quantitative measurements of the percentage of tdTomato⁺ cells with respect to the total cells in (c) (n = 6 mice per condition; three independent experiments). The data are presented as the means ± s.ds. h Quantitative measurements of the percentage of tdTomato⁺ cells with respect to the total cells in (d) (n = 6 mice per condition; three independent experiments). The data are presented as the means ± s.ds. i Quantitative measurements of the percentage of tdTomato⁺ cells with respect to total cells in (e) (n = 6 mice per condition; three independent experiments). The data are presented as the means ± s.ds. At least 1 000 cells of each sample were measured. 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