Otitis media in <i>Enpp1</i>^{<i>asj/asj</i>} mice.

<p>A, B: Representative images of pathological changes in the middle ears of <i>Enpp1</i>^<i>asj</i> mutant mice (B) compared with controls (A) at the age of 5 months. The middle ear cavity (MEC) of <i>Enpp1</i>^<i>asj</i> mutant mice is filled with effusions (black asterisk), fibroblastic and amorphous tissue masses (long arrows), and inflammatory cells (arrow head). Ectopic mineralization of the otic capsule is also evident in mutant mice (open arrow in B). Control mice show a clear middle ear cavity without fibroblastic proliferation (A). C, D: The thickness of the middle ear epithelium (double headed arrows) is greater in <i>Enpp1</i>^<i>asj</i> mutant mice (D) than controls (C). E, F: The stapedial artery wall (arrows) is thicker in <i>Enpp1</i>^<i>asj</i> mutant mice (F) than controls (E). G, H: Representative images of discharge in mutant mice (H) and littermate controls (G) at the age of 5 months. The external ear cavity of the mutant mice is filled with discharge (red asterisk), while control mice have a clear external ear canal and easily observable tympanic membrane (black asterisk). Scale bars: A, B = 200μm, C, D = 50μm, E, F = 80 μm.