The labeling intensity of Hes1 is reduced in Ascl1 knockout compared to heterozygote.

Multiple sections from various ages were stained for Hes1 and imaged. The intensity of nuclear labeling was sampled from 50 consecutive nuclei and pixel intensity for 50 single-pixel intensity readings were measured for Hes1(+) consecutive nuclei in the olfactory domain and the respiratory domain using ImageJ (in other words, unstained cells were not measured). A ratio of intensity values was calculated for olfactory epithelium to respiratory epithelium for each genotype at each embryonic time point described. At all time points examined the calculated OE/RE intensity ratio is less for Ascl1 knockoutmice than heterozygotes.