Skn-1a/Pou2f3 functions as a master regulator to generate Trpm5-expressing chemosensory cells in mice
Fig 4
Loss of the Trpm5-positive chemosensory cells in multiple tissues in Skn-1a-/- mice.
A: Two-color in situ hybridization of Skn-1a (green) and Trpm5 (magenta) in various tissues of auditory tube, urethra, thymus, and pancreatic duct of wild-type adult mice. The mRNA signals of Skn-1a were co-labeled with Trpm5 signals (arrowheads) in all tissues examined. Scale bar, 20 μm. B: Co-immunostaining using antibodies against Skn-1a (green) and villin (magenta) on cryosections of auditory tube, urethra, thymus, and pancreatic duct of wild-type adult mice. Skn-1a-positive cells were overlapped with villin-positive cells (arrowheads). The arrows indicate Skn-1a negative and villin-single positive cells. Scale bar, 20 μm. C: Double-label immunohistochemistry of Trpm5 and villin on sections of auditory tube, urethra, thymus, and pancreatic duct of wild-type (top) and Skn-1a-/- mice (bottom) was carried out to examine the impact of Skn-1a deficiency on Trpm5-positive chemosensory cells. Trpm5-positive cells were co-labeled with anti-villin antibody (arrowheads) in wild-type mice, whereas the expression of Trpm5 was abolished in all tested tissues in Skn-1a-/- mice. The immunoreactive signals for villin were detected in Skn-1a-/- urethral epithelium and thymic medulla (arrows), but not in auditory tube and pancreatic duct. Scale bar, 20 μm. D: The expression of taste signaling molecules (Tas1r3, Tas2r105, Tas2r108, Tas2r131, Gnat3, Plcb2, and Trpm5) in auditory tube, urethra, thymus, and pancreatic duct was examined by RT-PCR in wild-type (WT) and Skn-1a-/- (KO) mice. The expression of taste signaling molecules observed in wilt-type mice was not detected in Skn-1a-/- mice. A housekeeping gene, GAPDH was used as a positive control.