Skn-1a (Pou2f3) specifies taste receptor cell lineage.

Functional diversification of taste cells is crucial for proper discrimination of taste qualities. We found the homeodomain protein Skn-1a (Pou2f3) to be expressed in sweet, umami and bitter taste cells. Skn-1a-deficient mice lacked electrophysiological and behavioral responses to sweet, umami and bitter tastes, as a result of a complete absence of sweet, umami and bitter cells and the concomitant expansion of sour cells. Skn-1a is critical for generating and balancing the diverse composition of taste cells.