MKS3 mutant (B) sections stained with OMP (green) and
GAP-43 (red) showed high numbers of OMP+ cells at the
bottom of the OE (arrows) as compared to Control (A; nuclei are stained
with DRAQ5 (blue)). C: Quantification of the relative position of OMP
and GAP-43 expressing cells confirmed the unusual basally-oriented
distribution of OMP cells in MKS3 mutant rats (ANOVA
P<0.0001, Bonferroni post test values are shown in the table). There
was no significant change in the relative position of GAP43 cells
between genotypes. At a low magnification (as in A, B), the edge of the
epithelium appeared to be continuous in the control animals (as shown by
OMP staining), but had a discrete, interrupted staining pattern in the
mutant animals. At higher magnification (D, E), this appears to be due
to an increased frequency of OMP knobs (green) appearing to protrude
“above” the ciliary layer (as defined by AC3 (red) staining,
dashed line; nuclei are stained with DRAQ5 (blue)). Notice that OSN
knobs appeared to be bigger in the mutant animals (arrows in D and E).
Scale bars = 100 µm: shown in (A) for A
& B; 10 µm: shown in (D) for D & E.