Figure 3. Ablation of Bmpr1a in Prrx1⁺ in young mice led to microtia.

(A) A decrease in p-Smad1/5/9 on the ear sections of the Prrx1^CreERT; Bmpr1a^f/f mice that received Tamoxifen (TAM) at P21. Upper panel: Schedule for TAM administration and mouse euthanasia. Scale bars=20 μm. Arrows: positive signals. (B) qPCR analysis of Bmpr1a mRNA in the ear samples of the Prrx1^CreERT; Bmpr1a^f/f and control mice. n=3. (C) The ear phenotypes of the adult Prrx1^CreERT; Bmpr1a^f/f mice that received TAM at P21. Right panel: quantitation data. n=4. (D) H/E staining of ear sections from the mutant and control mice. Right panels: The thickness of the cartilage and the size of the chondrocytes in the ears of the mutant and control mice. Scale bars=50 μm. n=3. Unpaired two-tailed Student’s t-test were applied to evaluate the correlation data in (B and C). Two-way ANOVA (or mixed model) multiple comparisons were applied to evaluate the correlation data in (D), p<0.05 was considered as statistically significant.

Figure 3—figure supplement 1. Normal growth plate and articular cartilage in Prrx1^CreERT; Bmpr1a^f/f mice receiving Tamoxifen (TAM) at P21.

(A) Epiphysial sections of the Prrx1^CreERT; Bmpr1a^f/f and control mice. Scale bars=100 μm. (B) Articular sections of the Prrx1^CreERT; Bmpr1a^f/f and control mice. Scale bars=100 μm.