Table 1

Transgenic and knock-out mice used in this study

Abbreviation	Strain¹	Purpose and function
WT	Wild type	Control
TrpM5-GFP	Green fluorescent protein expression under the promotor for Transient receptor potential cation channel subfamily M member 5 (Trpm5)	SCC, taste cells, and MVC express GFP; immunohistochemical examination of the airway epithelium
Gnat3-KO	G-protein subunit α transducin 3 (gustducin) knock-out	Insufficiency of taste cells and SCCs
Trpm5-KO	Trpm5 knock-out	Insufficiency of taste cells and SCCs
Skn1a-KO	POU (Pit-Oct-Unc) homeodomain transcription factor (Skn-1a/Pou2f3) knock-out	Aplastic Type II taste cells and SCCs
P2X2/X3 Double KO	Purinergic receptors ATP-gated ion channels P2X2 and P2X3 double knock-out	Bitter-ageusic mouse that lacks taste avoidance of bitter substances, or taste preferences for sweet or umami