Figure 4:

Histological images of specimen previously used for contrast-enhanced microCT imaging and 3D reconstruction. A, A’, B: Control (Bmp4 ^f/f) C, C’, D: heterozygote specimen (Foxg1Cre;Bmp4 ^f/wt). E-H: mutant specimen (Foxg1Cre;Bmp4 ^f/f). Alcian blue staining in left and middle column. H&E stains in B, D, F, and H. Abnormal morphology of the larynx resulting from mesenchymal deletion of Bmp4 is detected in mutant samples. Laryngeal cartilage is present in the mutants (E – H) but morphology (shape) and thickness of the cartilage elements is not normal (compare thyroid cartilage (*) in panel C vs E). Tracheal cartilage is defective and mostly absent in mutants (compare panel E vs A). T= thyroid cartilage C= cricoid cartilage, A= arytenoid cartilage, E= epiglottis, H= basihyoid bone, Eso= esophagus, Trach= trachea.