The present invention relates to the discovery of several genes of the domestic dog (Canine familiaris) associated with taste perception. The invention provides, inter alia, the nucleotide sequence of the canine Tas1r1, Tas1r2, and Tas1r3 receptor genes, the amino acid sequences of the polypeptides encoded thereby, and antibodies to the polypeptides. The present invention also relates to methods for screening for compounds that modify the genes' function or activity, the compounds identified by such screens, and mimetics of the identified compounds. The invention further provides methods for modifying the taste preferences, ingestive responses, or general behavior of a mammal such as a dog by administering compounds that affect the function or activity of the gene or the polypeptide encoded thereby.