SPLTRAK Abstract Submission
   Bitter Taste Receptor T2R7 and Umami Taste Receptor Subunit T1R1 are Expressed Largely in Vimentin-Negative Taste Bud Cells of Chickens
Yuta Yoshida1,2, Zhonghou Wang1, Kayvan F. Tehrani1, Emily G. Pendleton1, Ryota Tanaka2, Luke J. Mortensen1, Shotaro Nishimura2, Shoji Tabata2, Hong-Xiang Liu1, Fuminori Kawabata3
1University of Georgia, Athens, GA, United States
2Kyushu University, Fukuoka, Japan
3Hirosaki University, Hirosaki, Japan

In the mammalian taste system, bitter taste is sensed by the taste receptor type 2 (T2R) family, and sweet and umami tastes are sensed by the heterodimer of the taste receptor type 1 (T1R) family. In the chicken genome, 3 T2R genes (T2R1, T2R2, and T2R7) and 2 T1R genes for the umami taste receptor (T1R1 and T1R3) have been detected. However, the distribution of these receptor proteins in the taste buds of chickens has not been elucidated. Here, we detected the localization of bitter taste receptor T2R7 and umami taste receptor subunit T1R1 in chicken taste buds, using a molecular marker for chicken taste buds, Vimentin. T2R7 and T1R1 were expressed in the taste bud clusters on the oral epithelial sheets of chickens, and among all three regions of gustatory tissues of chickens, the palate, base of the oral cavity, and the posterior tongue. The similar distribution patterns and numbers between taste bud clusters expressing these receptors and those expressing Vimentin on the oral epithelial sheets of chickens suggested that T2R7 and T1R1 were expressed in most of the taste bud clusters in chickens. Interestingly, T2R7 and T1R1 were hardly merged with Vimentin at the taste bud cell level, and 3-D image analyses clearly revealed that these receptors were expressed largely in Vimentin-negative taste bud cells. These results suggested that the taste bud cell populations, labeled by different markers, e.g., T2R7, T1R1, and Vimentin, may serve distinct functions in taste perception. Taken together, the present results suggested that chickens possess fundamental bitter and umami sensing mechanisms in the taste buds, and the mechanisms were broadly present in the oral cavity of chickens.