Inbred mouse strains differ in their responses to sweet taste stimuli. These differences partly depend on allelic variation of the Tas1r3 gene encoding the T1R3 taste receptor. Our genetic analyses using C57BL/6ByJ (B6) and 129P3/J (129) strains suggest that other loci are also involved and that some of them are sweetener-specific. To confirm the existence of such loci, and to eliminate the effect of the Tas1r3 locus, we crossed B6 inbred mice with 129.B6-Tas1r3 congenic mice; thus all mice in this cross had only B6 Tas1r3 allele. We started selective breeding of lines that show either a high (Gly-H) or a low (Gly-L) preference for 30 mM glycine from the crossed mice. Electrophysiological experiments have shown that the chorda tympani nerve responses to glycine and sucrose are higher in mice from the Gly-H mice compared with mice from the Gly-L line. Bilateral section of the chorda tympani and the glossophalyngeal nerves diminished the glycine preference only in the Gly-H mice. These results suggest that a peripheral taste mechanism distinct from the T1R3 receptor contributes glycine preference.