The genetic basis of preference for sweet substances among inbred strains of mice: preference ratio phenotypes and the alleles of the Sac and dpa loci

Abstract

Five inbred strains (129/J, BALB/cByJ, C3HeB/FeJ, C57BI/6J and DBA/2J) were examined with two-bottle (48 h) preference ratio testing across concentrations of sodium saccharin (3 x 10(-4) M, 10(-3) M, 3 x 10(-3) M and 10(-2) M), d-phenylalanine (10(-3) M, 10(-2) M and 10(-1) M), and l-glutamine (10(-2) M, 3 x 10(-2) M, 10(-1) M and 3 x 10(-1) M). Three consistent groupings of strains were observed across substances and concentrations: (1) C57BI/6J (preference at low and high concentrations); (2) BALB/cByJ and C3HeB/FeJ (preference at high concentrations); (3) 129/J and DBA/2J (preference at high concentration for sodium saccharin and indifference to d-phenylalanine and l-glutamine). If a single locus (presumably dpa or Sac) determines these phenotypes, there are likely to be three alleles. If two independent loci (presumably dpa and Sac) determine these phenotypes, an allelic assignment of Sacb/dpa+s for the C57BI/6J strain, Sacb/dpa-s for the BALB/cByJ and C3HeB/FeJ strains, and either Sacd/dpa+s or Sacd/dpa-s for the 129/J and DBA/2J strains is suggested.