Fig. 9: Creb5 is necessary to maintain appropriate zonal gene expression in the articular cartilage and blocks premature endochondral ossification of adjacent tissues in postnatal mice.

Gene expression assayed by RNAscope FISH in the hindlimbs of either P14 (a) or P30 (b) Aggrecan1^{tm(IRES-CreERT2)}; Creb5^flox9/flox9 mice or Creb5^flox9/flox9 littermates, that had been administered tamoxifen from postnatal days 1–11. In each row of images, the left two images depict the same section; and the right two images depict the same section. Scale bar equals 200 microns in a and b. c Safranin O/Fast Green staining of the anterior meniscus (and articular cartilage) in the knees of either P30 or P42 Aggrecan1^{tm(IRES-CreERT2)}; Creb5^flox9/flox9 mice or Creb5^flox9/flox9 littermates, that had been administered tamoxifen from postnatal days 1–11. Arrowheads indicate flat cells on the surface of the meniscus. Femur (F), Tibia (T), and Meniscus (M) are indicated. Scale bar equals 100 microns in c. P14 images were obtained from tissues of female mice; P30 and P42 images were obtained from tissues of either male or female mice. Similar results were obtained in at least 2 (a, b) or 3 (c) independent biological repeats.