Figure 4.
Normal morphology and expression of taste cell markers within circumvallate papillae of Rgs21-null mice. Circumvallate papillae of wild-type (n = 4) and Rgs21Δ5/Δ5 mice (n = 4) were stained with haematoxylin and eosin (H&E) (A, B; magnification of taste buds in C), or visualized by dual-color indirect immunofluorescence with the taste cell marker Troma-1 (anti-keratin-8 in red) and DNA dye (DAPI in blue) (D, E). There was no difference found in mean taste bud number per section (F; unpaired Student’s t-test; P = 0.5879) between knockout and wild-type animals. Equivalent detection of the Type II taste cell marker Trpm5 within CV sections was observed in both genotypes via in situ hybridization and subsequent confocal microscopy (G, H with antisense probe; I with sense probe). Equivalent mRNA expression was also observed by qRT-PCR for additional markers of Type I (Entpd2), Type II (Plcb2, Trpm5, Calhm1), and Type III (Snap25) taste cells (J). Bar graph displays the mean ± SEM; no difference between genotypes was statistically significant by Student’s t test.