Fig. 3. Structural alteration of the Hmx2^lacZnull inner ears as shown by ß-galactosidase activity in whole-mount embryos and dissected inner ears. The embryonic stages are indicated on the left. The genotype of each embryo is shown at the top. E and F are high power views of dissected Hmx2^lacZ+/– and Hmx2^lacZ–/– inner ears. Arrows in A-D indicate the positions of the inner ear. Arrowheads in panel A and B indicate Hmx2^lacZ expression in the developing neural tube and hypothalamus. In total, more than 20 embryos of each genotype from different embryonic stages were examined. CD, cochlear duct; ES, endolymphatic sac; LD, lateral semicircular duct; PD, posterior semicircular duct; S, saccule; SD, superior semicircular duct; SV, stria vascularis; VD, vestibular diverticulum.