(A, B) Box-and-whisker plots of the total number of hair cells at 38 hpf (A) and mature SAG neurons at 36 hpf (B) in control, sox2−/−, sox3−/−, and sox2−/−; sox3−/− double mutant embryos. Green lines represent means. Asterisks indicate statistically significant differences compared to controls (***P<0.001, Tukey’s HSD test following ANOVA). (C-H) Dorsolateral views (anterior to left) of expression of atoh1a (C-E) and neurog1 (F-H) at 24 hpf in control embryos, hs:sox2/+ heterozygotes and hs:sox3/+ heterozygotes. Embryos were heat shocked at 12.5 hpf, 38°C or 39°C for 30 minutes, as indicated. (I-L) Expression of atoh1a (I, J) and neurog1 (K, L) at 24 hpf in cross sections through the middle of the otic vesicle in control embryos (I, K) and hs:sox3/+ heterozygotes (J, L). Embryos were heat shocked at 12.5 hpf, 38°C for 30 minutes. Otic vesicle borders are outlined in C-L. (M, N) Quantification of the total number of hair cells (M) and mature SAG neurons (N) at 30 hpf in control and hs:sox2/+ embryos. (O, P) Quantification of the total number of hair cells (O) and mature SAG neurons (P) at 31 hpf in control and hs:sox3/+ embryos. Error bars represent standard deviation in M-P, and asterisks indicate statistically significant differences relative to controls (*P<0.05, ***P<0.001, student’s t-test, n>13).