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.

Ethanol Consumption and Taste Preferences in C57BL/6ByJ and 129/J Mice

“…Although there still may have been interactions between solutions tested in this study, it seems unlikely that they would be sufficiently robust to affect the main conclusions about the direction of strain differences between B6 and 129 strains. Indeed, in our other experiments on these strains, 9,20,30 as well as in studies by other authors, 5,8,[10][11][12]15 B6 and 129 mice had the same character of differences in ethanol, sucrose, saccharin, citric acid, quinine, and NaCl consumption, regardless of whether the solutions were tested in the same or in different groups of animals.…”

“…Although there still may have been interactions between solutions tested in this study, it seems unlikely that they would be sufficiently robust to affect the main conclusions about the direction of strain differences between B6 and 129 strains. Indeed, in our other experiments on these strains, 9,20,30 as well as in studies by other authors, 5,8,[10][11][12]15 B6 and 129 mice had the same character of differences in ethanol, sucrose, saccharin, citric acid, quinine, and NaCl consumption, regardless of whether the solutions were tested in the same or in different groups of animals.To summarize, the higher ethanol consumption of B6 mice relative to 129 mice is accompanied by higher preferences for sweet and sour, possible reduction in the aversion to bitter, no change in capsaicin sensitivity, and a lower preference for salty taste. These data are consistent with the hypothesis that the higher ethanol intake by B6 mice depends, in part, on higher hedonic attractiveness of its sweet taste component.…”

“…5 Consistent with our finding of a difference between the two strains in sucrose intake, there is evidence that B6 mice have higher intakes than do 129 mice of several sweet compounds, including sucrose, 10 saccharin, 5,10-12 acesulfame, dulcin, 10 glycine, 13 d-phenylalanine, and l-glutamine. 12 A positive relationship between alcohol intake and sweet solution intake has also been found among other inbred strains of mice 5 and rats, 3,4 and within F 2 hybrids from ethanolpreferring and ethanol-nonpreferring rat strains. 3 Because these studies encompass a wide variety of nutritive and nonnutritive sweeteners, some of which are believed to have no postingestive effects, the results support the contention there is a genetically determined link between alcohol intake and sweet taste perception.…”

Allelic Variation of theTas1r3Taste Receptor Gene Selectively Affects Behavioral and Neural Taste Responses to Sweeteners in the F2Hybrids between C57BL/6ByJ and 129P3/J Mice

“…Several other lines of evidence also suggest that behavioral responses to sweeteners depend on genes other than Tas1r3. These involve multigenic inheritance of sweetener consumption shown in several studies (Ramirez and Fuller, 1976;Phillips et al, 1994;Capeless and Whitney, 1995;Lush et al, 1995;Bachmanov et al, 1996b), the linkage of sweet taste responses to the dpa locus on proximal chromosome 4 (Ninomiya et al, , 1991Capeless and Whitney, 1995;Bachmanov et al, 1997), and linkages for sweetener consumption detected in our genome scan of the B6 ϫ 129 inter- Responses in these mice relative to 100 mM NH 4 Cl were, respectively: 1000 mM sucrose: 0.60, 2.49, and 2.40; 20 mM saccharin: 0.33, 2.11, and 1.50; 1000 mM glycine: 0.84, 0.59, and 0.94. Relative responses to sucrose and saccharin were higher in the Tas1r3 B6 homozygote and heterozygote compared with the 129/129 homozygote.…”

Behavioral Discrimination between Sucrose and Other Natural Sweeteners in Mice: Implications for the Neural Coding of T1R Ligands

“…The B6 strain was chosen because it (1) is the most common mouse strain used in taste research, (2) has been characterized previously as a "taster" strain (Capretta, 1970;Pelz et al, 1973;Fuller, 1974;Lush, 1989;Capeless and Whitney, 1995;Bachmanov et al, 1996), and (3) serves as a background strain in many knock-out, congenic, and transgenic manipulations (Damak et al, 2003;Zhao et al, 2003). Six to 7 d after arrival, mice were put on a restricted water-access schedule with fluid available during testing only.…”