Fig. 4. Complementary phenotypes of Math1 and Ngn1 mutants. (A,B) Ectopic Ngn1 expression in the E13.5 wild-type and Math1^-/- utricle. Axes apply to all images. (C) Ectopic Math1 expression in the E13.5 wild-type and Ngn1^-/- utricle. (D-M) Expression of Ngn1-GFP transgene (cyan), myosin VIIa protein (red) and Math1 mRNA in wild-type, Math1 and Ngn1 mutant utricles at E14.5. Brackets in E,G indicate abnormal overlap of neural precursors and hair cells in heterozygotes. Arrowheads in K-M indicate macular expansion in Ngn1 mutants. (N) NeuroD⁺ epithelial cell numbers in utricle and saccule of Math1^-/- and wild-type littermates over time. Asterisks denote significance at P<0.05. Points represent the mean and standard deviation of three ears from separate litters. (O) Utricular maculae of wild-type and Ngn1^+/- littermates at E14.5, hybridized identically for Math1. Scale bars: 50 µm.