Skeletal phenotypes of the Koa / Koa mice. (A and B) Ventrolateral view of ribs of +/+ (A) and Koa/Koa (B) mice. Arrows indicate abnormal curvature of the ribs in Koa/Koa mice. (C and D) Skull of +/+ (C) and Koa/Koa (D) mice with dorsal views. Arrowheads and arrows indicate expanded zygomatic arches and deformed zygomatic processes of Koa/Koa mice, respectively.