No relationship between sequence variation in protein coding regions of the Tas1r3 gene and saccharin preference in rats.
Nearly all mammalian species like sweet-tasting foods and drinks, but there are differences in the degree of 'sweet tooth' both between species and among individuals of the same species. Some individual differences can be explained by genetic variability. Polymorphisms in a sweet taste receptor (Tas1r3) account for a large fraction of the differences in consumption of sweet solutions among inbred mouse strains. We wondered whether mice and rats share the same Tas1r3 alleles, and whether this gene might explain the large difference in saccharin preference among rats. We conducted three experiments to test this. We examined DNA sequence differences in the Tas1r3 gene among rats that differed in their consumption of saccharin in two-bottle choice tests. The animals tested were from an outbred strain (Sprague-Dawley; experiment 1), selectively bred to be high- or low-saccharin consumers (HiS and LoS; experiment 2), or from inbred strains with established differences in saccharin preference (FH/Wjd and ACI; experiment 3). Although there was considerable variation in saccharin preference among the rats there was no variation in the protein-coding regions of the Tas1r3 gene. DNA variants in intronic regions were detected in 1 (of 12) outbred rat with lower-than-average saccharin preference and in the ACI inbred strain, which also has a lower saccharin preference than the FH/Wjd inbred partner strain. Possible effects of these intronic nucleotide variants on Tas1r3 gene expression or the presence of T1R3 protein in taste papillae were evaluated in the ACI and FH/Wjd strains. Based upon the results of these studies, we conclude that polymorphisms in the protein-coding regions of the sweet receptor gene Tas1r3 are uncommon and do not account for individual differences in saccharin preference for these strains of rats. DNA variants in intron 4 and 5 are more common but appear to be innocuous.
Lu
Ke
K
Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA.
McDaniel
Amanda H
AH
Tordoff
Michael G
MG
Li
Xia
X
Beauchamp
Gary K
GK
Bachmanov
Alexander A
AA
VanderWeele
Dennis A
DA
Chapman
Clinton D
CD
Dess
Nancy K
NK
Huang
Liquan
L
Wang
Hong
H
Reed
Danielle R
DR
D000818:Animals; D002755:Choice Behavior / Q000502:physiology*; D005518:Food Preferences / Q000502:physiology*; D014644:Genetic Variation; D011110:Polymorphism, Genetic; D051381:Rats; D011919:Rats, Inbred Strains; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology*; D043562:Receptors, G-Protein-Coupled; D012439:Saccharin / Q000378:metabolism*; D016415:Sequence Alignment; D013045:Species Specificity; D013549:Sweetening Agents / Q000378:metabolism
D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D013549:Sweetening Agents; C431926:taste receptors, type 1; D012439:Saccharin
Alcohol Clin Exp Res. 1993 Apr;17(2):366-9
8488981
Genes Brain Behav. 2003 Jun;2(3):125-31
12931785
Chem Senses. 2004 Jul;29(6):523-8
15269124
Alcohol. 1992 May-Jun;9(3):203-6
1605887
Adv Child Dev Behav. 1979;13:257-95
484324
Methods. 2001 Dec;25(4):402-8
11846609
Nat Neurosci. 1999 Dec;2(12):1055-62
10570481
Alcohol Alcohol. 1999 May-Jun;34(3):386-95
10414615
Biochem Biophys Res Commun. 2001 Apr 27;283(1):236-42
11322794
Behav Genet. 2002 Sep;32(5):363-88
12405517
Behav Genet. 2002 Jan;32(1):57-67
11958543
Nucleic Acids Res. 2003 Jul 1;31(13):3497-500
12824352
Cell. 2001 Aug 10;106(3):381-90
11509186
Cell. 1999 Feb 19;96(4):541-51
10052456
Alcohol Alcohol. 1999 May-Jun;34(3):378-85
10414614
Nat Neurosci. 2001 May;4(5):492-8
11319557
Chem Senses. 2001 Sep;26(7):925-33
11555487
J Comp Physiol Psychol. 1959 Aug;52:451-7
14425687
Chem Senses. 1996 Apr;21(2):147-57
8670693
Neurosci Biobehav Rev. 2001 Jan;25(1):53-74
11166078
Mamm Genome. 1997 Aug;8(8):545-8
9250857
Alcohol. 1998 Nov;16(4):275-8
9818978
FEMS Microbiol Lett. 1999 May 15;174(2):247-50
10339815
Mamm Genome. 2001 Jan;12(1):13-6
11178737
Chem Senses. 2001 Sep;26(7):905-13
11555485
Nat Genet. 2001 May;28(1):58-63
11326277
Physiol Behav. 1981 Dec;27(6):971-6
7335816
Ann Hum Biol. 2001 Mar-Apr;28(2):111-42
11293722
J Comp Physiol Psychol. 1963 Jun;56:465-75
14002818
Physiol Behav. 2000 May;69(3):247-57
10869590
J Neurosci. 2004 Jan 28;24(4):938-46
14749438
Ann Med Intern Fenn. 1967;56(4):137-53
5587534
Proc Natl Acad Sci U S A. 2002 Apr 2;99(7):4692-6
11917125
J Neurosci. 2004 Mar 3;24(9):2296-303
14999080
Proc Natl Acad Sci U S A. 1935 Feb;21(2):84-90
16587943
J Neurochem. 2001 May;77(3):896-903
11331418
Physiol Behav. 1998 Nov 15;65(2):393-6
9855493