Molecular genetic identification of a candidate receptor gene for sweet taste

A cDNA clone encoding a novel member of the putative taste receptor T1R fam ily, designated T1R3, was isolated from circumvallate papillae of the mouse tongue using degenerate primers. Reverse transcription-polymerase chain re action analysis showed predominant expression of the receptor in circumvall ate papillae. In situ hybridization analysis revealed that T1R3 was express ed in a subset of taste receptor cells in taste buds and that the topograph ic distribution of T1R3 in various taste papillae was different from those of the other T1R members. Genetic mapping of T1R3 with a mouse/hamster radi ation hybrid panel located the gene on the distal end of mouse chromosome 4 correlated with the Sac locus affecting sweet sensitivity of mice. Our res ults indicate that T1R3 may serve as the receptor for sweet perception in m ice. (C) 2001 Academic Press.