Fig. 6: Otitis media, and alterations in motile cilia in the absence of TUBB4B.

A Images of the tympanic membrane from 1-month-old Tubb4b^−/− and control littermate. Scale bar = 0.5 mm. The tympanic membrane is denoted with an asterisk. B Cross-section of auditory bullae from 1-month-old Tubb4b^−/− and control littermate, stained with Hematoxylin and Eosin (H&E). Scale bar = 100 μm. Top panel: Magnified view of ciliated middle ear epithelium near Eustachian tube (ET). Scale bar = 10 μm. Bottom panel: Magnified view of ciliated middle ear epithelium in the dorsal region of the middle ear cavity (MEC). Scale bar =  10 μm. Black arrowheads point to the shortened cilia; black arrow points to the cells missing cilia in the Tubb4b^−/− middle ear. Effusion in the MEC is marked with a black star. C Cross-section of auditory bullae at P10 (top) and P15 (bottom) from Tubb4b^−/− and control littermate, stained with H&E. Scale bar = 50 μm. D Ciliated middle ear epithelium near ET stained with TUBB4 (green) and acetylated tubulin (magenta, cilia marker) antibodies and DAPI. White arrowheads point to the shortened cilia in the Tubb4b^−/− middle ear. Scale bar = 10 μm. D’ Ciliated middle ear epithelium in the dorsal region of the MEC stained with TUBB4 (green) and acetylated tubulin (magenta) antibodies and DAPI (blue). White arrowheads point to the shortened cilia; white arrow points to the cells missing cilia in the Tubb4b^−/− middle ear. Scale bar = 10 μm. E Scanning electron microscopy (SEM) of the middle ear near the ET from P10 Tubb4b^−/− and control littermates. White arrowheads point to the shortened cilia in the Tubb4b^−/− middle ear. Scale bar = 5 μm. F Magnified SEM view of ciliated cells in the middle ear of Tubb4b^−/− at P10. White arrowheads point to the shortened cilia in Tubb4b^−/− middle ear. Scale bar  = 2 μm. ET Eustachian tube, MEC middle ear cavity, Co cochlea.