Figure 3

Morphological analysis of innervated fungiform taste buds at birth. (A) Volume of taste buds was measured in point mutants and respective controls at birth (P0) as a readout for morphology (Trkb^P/P 11,999 ± 2,868 μm³ vs. Trkb^W/W 10,784 ± 2,743 μm³, P = 0.904), n = 3 for each genotype (taste buds analysed: Trkb^P/P n = 21; Trkb^W/W n = 28); (Trkb^D/D 2,296 ± 1,254 μm³), n = 3 (n = 14 taste buds), P <0.001 vs. Trkb^W/W and Trkb^P/P. (B–G) Representative images of tongue sections double immunostained with TROMA-I and TUJ1 antibodies to visualize taste buds (B, D, F) and innervated taste buds in fungiform papillae (C, E, G) for Trkb^W/W control, Trkb^P/P, and Trkb^D/D mutants. (H) Taste bud morphology of Trkb^S/S mutants and respective controls. Volume (Trkb^S/S 3,537 ± 1,504 μm³ vs. Trkb^+/+ 8,006 ± 2,497 μm³, P <0.001), n = 3 each genotype (taste buds: Trkb^+/+; n = 24; Trkb^S/S n = 14). (I–L) TROMA-1 immunostaining highlights taste buds in Trkb^+/+ and Trkb^S/S(I, K). Innervated taste buds within the fungiform papillae are revealed by double immunostaining of TROMA-1 and TUJ1 antibodies (J, L). (M) Comparison between Trkb^S/S and Trkb^D/D mutant taste bud morphology volume (Trkb^S/S vs. Trkb^D/D, P = 0.403), revealing similar reduction in fungiform taste bud size of the two genotypes. P statistic from unpaired Student’s t-test; mean ± s.d. Scale bars, (G, L) 10 μm.