Figure 3
Fewer cells express markers of young (βIII-tubulin) and mature (olfactory marker protein) olfactory receptor neurons in the OE of Insm1-/-embryos. (A-D) Immunohistochemistry for βIII-tubulin (red) plus (C-D) olfactory marker protein (OMP; green) in representative, anatomically aligned images from the OE of (A, B) E14.5 and (C, D) E18.5 Insm1-/-and an Insm1+/+littermate embryo. Fewer cells express either marker in the knockout (KO). The apical border is toward the center of each panel, and the basal lamina is toward the periphery. (E) Density of young neurons (number of cells expressing βIII-tubulin per (100 μm)2) in OE at various embryonic stages. In Insm1-/-mice at E11.5, E12.5, E14.5, and E18.5 the number of young neurons (red) is reduced by an average of 43% (n = 3 embryo pairs, total of 9 aligned section pairs, P < 0.05), 46% (n = 3 embryo pairs, total of 9 aligned section pairs, P < 0.05), 39% (n = 4 embryo pairs, total of 15 aligned section pairs, P < 0.01), and 37% (n = 3 embryo pairs, total of 9 aligned section pairs, P < 0.05), respectively. At E10.5, the measured reduction (29%, n = 3 embryo pairs, total of 9 aligned section pairs) does not achieve statistical significance. (F) Density of mature neurons (number of cells expressing OMP per (100 μm)2) in OE at various embryonic stages. At E14.5 and E18.5 the number of mature olfactory neurons is reduced by 92% (n = 3 embryo pairs, total of 9 aligned section pairs, P < 0.01) and 94% (n = 3 embryo pairs, total of 9 aligned section pairs, P < 0.001), respectively. Data in (E, F) are presented as mean values ± standard error of the mean (SEM). *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001. Scale bars: 50 μm. WT, wild type.