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Lin C, Fesi BD, Marquis M, Bosak NP, Lysenko A, Koshnevisan MA, Duke FF, Theodorides ML, Nelson TM, McDaniel AH, Avigdor M, Arayata CJ, Shaw L, Bachmanov AA, Reed DR. Burly1 is a mouse QTL for lean body mass that maps to a 0.8-Mb region of chromosome 2. Mamm Genome 2018; 29:325-343. [PMID: 29737391 DOI: 10.1007/s00335-018-9746-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 04/26/2018] [Indexed: 11/25/2022]
Abstract
To fine map a mouse QTL for lean body mass (Burly1), we used information from intercross, backcross, consomic, and congenic mice derived from the C57BL/6ByJ (host) and 129P3/J (donor) strains. The results from these mapping populations were concordant and showed that Burly1 is located between 151.9 and 152.7 Mb (rs33197365 to rs3700604) on mouse chromosome 2. The congenic region harboring Burly1 contains 26 protein-coding genes, 11 noncoding RNA elements (e.g., lncRNA), and 4 pseudogenes, with 1949 predicted functional variants. Of the protein-coding genes, 7 have missense variants, including genes that may contribute to lean body weight, such as Angpt41, Slc52c3, and Rem1. Lean body mass was increased by the B6-derived variant relative to the 129-derived allele. Burly1 influenced lean body weight at all ages but not food intake or locomotor activity. However, congenic mice with the B6 allele produced more heat per kilogram of lean body weight than did controls, pointing to a genotype effect on lean mass metabolism. These results show the value of integrating information from several mapping populations to refine the map location of body composition QTLs and to identify a short list of candidate genes.
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Workman AD, Maina IW, Brooks SG, Kohanski MA, Cowart BJ, Mansfield C, Kennedy DW, Palmer JN, Adappa ND, Reed DR, Lee RJ, Cohen NA. The Role of Quinine-Responsive Taste Receptor Family 2 in Airway Immune Defense and Chronic Rhinosinusitis. Front Immunol 2018; 9:624. [PMID: 29643854 PMCID: PMC5882797 DOI: 10.3389/fimmu.2018.00624] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/13/2018] [Indexed: 11/17/2022] Open
Abstract
Background Bitter (T2R) and sweet (T1R) taste receptors in the airway are important in innate immune defense, and variations in taste receptor functionality in one T2R (T2R38) correlate with disease status and disease severity in chronic rhinosinusitis (CRS). Quinine is a bitter compound that is an agonist for several T2Rs also expressed on sinonasal cells, but not for T2R38. Because of this property, quinine may stimulate innate immune defense mechanisms in the airway, and functional differences in quinine perception may be reflective of disease status in CRS. Methods Demographic and taste intensity data were collected prospectively from CRS patients and non-CRS control subjects. Sinonasal tissue from patients undergoing rhinologic surgery was also collected and grown at an air–liquid interface (ALI). Nitric oxide (NO) production and dynamic regulation of ciliary beat frequency in response to quinine stimulation were assessed in vitro. Results Quinine reliably increased ciliary beat frequency and NO production in ALI cultures in a manner consistent with T2R activation (p < 0.01). Quinine taste intensity rating was performed in 328 CRS patients and 287 control subjects demonstrating that CRS with nasal polyps (CRSwNP) patients rated quinine as significantly less intense than did control subjects. Conclusion Quinine stimulates airway innate immune defenses by increasing ciliary beat frequency and stimulating NO production in a manner fitting with T2R activation. Patient variability in quinine sensitivity is observed in taste intensity ratings, and gustatory quinine “insensitivity” is associated with CRSwNP status. Thus, taste tests for quinine may be a biomarker for CRSwNP, and topical quinine has therapeutic potential as a stimulant of innate defenses.
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Lin C, Fesi BD, Marquis M, Bosak NP, Lysenko A, Koshnevisan MA, Duke FF, Theodorides ML, Nelson TM, McDaniel AH, Avigdor M, Arayata CJ, Shaw L, Bachmanov AA, Reed DR. Adiposity QTL Adip20 decomposes into at least four loci when dissected using congenic strains. PLoS One 2017; 12:e0188972. [PMID: 29194435 PMCID: PMC5711020 DOI: 10.1371/journal.pone.0188972] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 11/16/2017] [Indexed: 01/03/2023] Open
Abstract
An average mouse in midlife weighs between 25 and 30 g, with about a gram of tissue in the largest adipose depot (gonadal), and the weight of this depot differs between inbred strains. Specifically, C57BL/6ByJ mice have heavier gonadal depots on average than do 129P3/J mice. To understand the genetic contributions to this trait, we mapped several quantitative trait loci (QTLs) for gonadal depot weight in an F2 intercross population. Our goal here was to fine-map one of these QTLs, Adip20 (formerly Adip5), on mouse chromosome 9. To that end, we analyzed the weight of the gonadal adipose depot from newly created congenic strains. Results from the sequential comparison method indicated at least four rather than one QTL; two of the QTLs were less than 0.5 Mb apart, with opposing directions of allelic effect. Different types of evidence (missense and regulatory genetic variation, human adiposity/body mass index orthologues, and differential gene expression) implicated numerous candidate genes from the four QTL regions. These results highlight the value of mouse congenic strains and the value of this sequential method to dissect challenging genetic architecture.
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Workman AD, Brooks SG, Kohanski MA, Blasetti MT, Cowart BJ, Mansfield C, Kennedy DW, Palmer JN, Adappa ND, Reed DR, Cohen NA. Bitter and sweet taste tests are reflective of disease status in chronic rhinosinusitis. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2017; 6:1078-1080. [PMID: 29054707 DOI: 10.1016/j.jaip.2017.09.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/07/2017] [Accepted: 09/01/2017] [Indexed: 10/24/2022]
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Hariri BM, McMahon DB, Chen B, Freund JR, Mansfield CJ, Doghramji LJ, Adappa ND, Palmer JN, Kennedy DW, Reed DR, Jiang P, Lee RJ. Flavones modulate respiratory epithelial innate immunity: Anti-inflammatory effects and activation of the T2R14 receptor. J Biol Chem 2017; 292:8484-8497. [PMID: 28373278 DOI: 10.1074/jbc.m116.771949] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 03/21/2017] [Indexed: 12/18/2022] Open
Abstract
Chronic rhinosinusitis has a significant impact on patient quality of life, creates billions of dollars of annual healthcare costs, and accounts for ∼20% of adult antibiotic prescriptions in the United States. Because of the rise of resistant microorganisms, there is a critical need to better understand how to stimulate and/or enhance innate immune responses as a therapeutic modality to treat respiratory infections. We recently identified bitter taste receptors (taste family type 2 receptors, or T2Rs) as important regulators of sinonasal immune responses and potentially important therapeutic targets. Here, we examined the immunomodulatory potential of flavones, a class of flavonoids previously demonstrated to have antibacterial and anti-inflammatory effects. Some flavones are also T2R agonists. We found that several flavones inhibit Muc5AC and inducible NOS up-regulation as well as cytokine release in primary and cultured airway cells in response to several inflammatory stimuli. This occurs at least partly through inhibition of protein kinase C and receptor tyrosine kinase activity. We also demonstrate that sinonasal ciliated epithelial cells express T2R14, which closely co-localizes (<7 nm) with the T2R38 isoform. Heterologously expressed T2R14 responds to multiple flavones. These flavones also activate T2R14-driven calcium signals in primary cells that activate nitric oxide production to increase ciliary beating and mucociliary clearance. TAS2R38 polymorphisms encode functional (PAV: proline, alanine, and valine at positions 49, 262, and 296, respectively) or non-functional (AVI: alanine, valine, isoleucine at positions 49, 262, and 296, respectively) T2R38. Our data demonstrate that T2R14 in sinonasal cilia is a potential therapeutic target for upper respiratory infections and that flavones may have clinical potential as topical therapeutics, particularly in T2R38 AVI/AVI individuals.
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Guo Y, Hwang LD, Li J, Eades J, Yu CW, Mansfield C, Burdick-Will A, Chang X, Chen Y, Duke FF, Zhang J, Fakharzadeh S, Fennessey P, Keating BJ, Jiang H, Hakonarson H, Reed DR, Preti G. Genetic analysis of impaired trimethylamine metabolism using whole exome sequencing. BMC MEDICAL GENETICS 2017; 18:11. [PMID: 28196478 PMCID: PMC5310055 DOI: 10.1186/s12881-017-0369-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 01/17/2017] [Indexed: 12/27/2022]
Abstract
Background Trimethylaminuria (TMAU) is a genetic disorder whereby people cannot convert trimethylamine (TMA) to its oxidized form (TMAO), a process that requires the liver enzyme FMO3. Loss-of-function variants in the FMO3 gene are a known cause of TMAU. In addition to the inability to metabolize TMA precursors like choline, patients often emit a characteristic odor because while TMAO is odorless, TMA has a fishy smell. The Monell Chemical Senses Center is a research institute with a program to evaluate people with odor complaints for TMAU. Methods Here we evaluated ten subjects by (1) odor evaluation by a trained sensory panel, (2) analysis of their urine concentration of TMA relative to TMAO before and after choline ingestion, and (3) whole exome sequencing as well as subsequent variant analysis of all ten samples to investigate the genetics of TMAU. Results While all subjects reported they often emitted a fish-like odor, none had this malodor during sensory evaluation. However, all were impaired in their ability to produce >90% TMAO/TMA in their urine and thus met the criteria for TMAU. To probe for genetic causes, the exome of each subject was sequenced, and variants were filtered by genes with a known (FMO3) or expected effect on TMA metabolism function (other oxidoreductases). We filtered the remaining variants by allele frequency and predicated functional effects. We identified one subject that had a rare loss-of-function FMO3 variant and six with more common decreased-function variants. In other oxidoreductases genes, five subjects had four novel rare single-nucleotide polymorphisms as well as one rare insertion/deletion. Novel in this context means no investigators have previously linked these variants to TMAU although they are in dbSNP. Conclusions Thus, variants in genes other than FMO3 may cause TMAU and the genetic variants identified here serve as a starting point for future studies of impaired TMA metabolism. Electronic supplementary material The online version of this article (doi:10.1186/s12881-017-0369-8) contains supplementary material, which is available to authorized users.
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Lipchock SV, Spielman AI, Mennella JA, Mansfield CJ, Hwang LD, Douglas JE, Reed DR. Caffeine Bitterness is Related to Daily Caffeine Intake and Bitter Receptor mRNA Abundance in Human Taste Tissue. Perception 2017; 46:245-256. [PMID: 28118781 DOI: 10.1177/0301006616686098] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We investigated whether the abundance of bitter receptor mRNA expression from human taste papillae is related to an individual's perceptual ratings of bitter intensity and habitual intake of bitter drinks. Ratings of the bitterness of caffeine and quinine and three other bitter stimuli (urea, propylthiouracil, and denatonium benzoate) were compared with relative taste papilla mRNA abundance of bitter receptors that respond to the corresponding bitter stimuli in cell-based assays ( TAS2R4, TAS2R10, TAS2R38, TAS2R43, and TAS2R46). We calculated caffeine and quinine intake from a food frequency questionnaire. The bitterness of caffeine was related to the abundance of the combined mRNA expression of these known receptors, r = 0.47, p = .05, and self-reported daily caffeine intake, t(18) = 2.78, p = .012. The results of linear modeling indicated that 47% of the variance among subjects in the rating of caffeine bitterness was accounted for by these two factors (habitual caffeine intake and taste receptor mRNA abundance). We observed no such relationships for quinine but consumption of its primary dietary form (tonic water) was uncommon. Overall, diet and TAS2R gene expression in taste papillae are related to individual differences in caffeine perception.
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Bobowski N, Reed DR, Mennella JA. Variation in the TAS2R31 bitter taste receptor gene relates to liking for the nonnutritive sweetener Acesulfame-K among children and adults. Sci Rep 2016; 6:39135. [PMID: 27966661 PMCID: PMC5155417 DOI: 10.1038/srep39135] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 11/17/2016] [Indexed: 01/08/2023] Open
Abstract
The nonnutritive sweetener (NNS) acesulfame potassium (Ace-K) elicits a bitter off-taste that varies among adults due to polymorphisms in a bitter taste receptor gene. Whether polymorphisms affect liking for Ace-K by children, who live in different sensory worlds, is unknown. We examined hedonic response to Ace-K among children compared to adults, and whether response was related to common variants of the TAS2R31 bitter taste receptor gene and to NNS intake. Children (N = 48) and their mothers (N = 34) rated liking of Ace-K, and mothers reported whether they or their children ever consume NNSs via questionnaire. Participants were genotyped for TAS2R31 variant sites associated with adult perception of Ace-K (R35W, L162M, A227V, and V240I). Regardless of age, more participants with 1 or no copies than with 2 copies of the TAS2R31 WMVI haplotype liked Ace-K (p = 0.01). NNS-sweetened products were consumed by 50% and 15% of mothers and children, respectively, with no association between intake and TAS2R31. The TAS2R31 WMVI haplotype was partly responsible for children’s hedonic response to Ace-K, highlighting a potential role for inborn differences in vulnerability to overconsumption of Ace-K-containing products. Currently available methods to measure NNS intake yield crude estimates at best, suggesting self-reports are not reflective of actual intake.
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Chang EH, Willis AL, McCrary HC, Noutsios GT, Le CH, Chiu AG, Mansfield CJ, Reed DR, Brooks SG, Adappa ND, Palmer JN, Cohen NG, Stern DA, Guerra S, Martinez FD. Association between the CDHR3 rs6967330 risk allele and chronic rhinosinusitis. J Allergy Clin Immunol 2016; 139:1990-1992.e2. [PMID: 27923563 DOI: 10.1016/j.jaci.2016.10.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 09/15/2016] [Accepted: 10/10/2016] [Indexed: 11/28/2022]
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Hwang LD, Breslin PAS, Reed DR, Zhu G, Martin NG, Wright MJ. Is the Association Between Sweet and Bitter Perception due to Genetic Variation? Chem Senses 2016; 41:737-744. [PMID: 27506221 DOI: 10.1093/chemse/bjw083] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Perceived intensities of sweetness and bitterness are correlated with one another and each is influenced by genetics. The extent to which these correlations share common genetic variation, however, remains unclear. In a mainly adolescent sample ( n = 1901, mean age 16.2 years), including 243 monozygotic (MZ) and 452 dizygotic (DZ) twin pairs, we estimated the covariance among the perceived intensities of 4 bitter compounds (6- n -propylthiouracil [PROP], sucrose octa-acetate, quinine, caffeine) and 4 sweeteners (the weighted mean ratings of glucose, fructose, neohesperidine dihydrochalcone, aspartame) with multivariate genetic modeling. The sweetness factor was moderately correlated with sucrose octa-acetate, quinine, and caffeine ( rp = 0.35-0.40). This was mainly due to a shared genetic factor ( rg = 0.46-0.51) that accounted for 17-37% of the variance in the 3 bitter compounds' ratings and 8% of the variance in general sweetness ratings. In contrast, an association between sweetness and PROP only became evident after adjusting for the TAS2R38 diplotype ( rp increased from 0.18 to 0.32) with the PROP genetic factor accounting for 6% of variance in sweetness. These genetic associations were not inflated by scale use bias, as the cross-trait correlations for both MZ and DZ twins were weak. There was also little evidence for mediation by cognition or behavioral factors. This suggests an overlap of genetic variance between perceptions of sweetness and bitterness from a variety of stimuli, which includes PROP when considering the TAS2R38 diplotype. The most likely sources of shared variation are within genes encoding post-receptor transduction mechanisms common to the various taste G protein-coupled receptors.
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Bachmanov AA, Bosak NP, Glendinning JI, Inoue M, Li X, Manita S, McCaughey SA, Murata Y, Reed DR, Tordoff MG, Beauchamp GK. Genetics of Amino Acid Taste and Appetite. Adv Nutr 2016; 7:806S-22S. [PMID: 27422518 PMCID: PMC4942865 DOI: 10.3945/an.115.011270] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The consumption of amino acids by animals is controlled by both oral and postoral mechanisms. We used a genetic approach to investigate these mechanisms. Our studies have shown that inbred mouse strains differ in voluntary amino acid consumption, and these differences depend on sensory and nutritive properties of amino acids. Like humans, mice perceive some amino acids as having a sweet (sucrose-like) taste and others as having an umami (glutamate-like) taste. Mouse strain differences in the consumption of some sweet-tasting amino acids (d-phenylalanine, d-tryptophan, and l-proline) are associated with polymorphisms of a taste receptor, type 1, member 3 gene (Tas1r3), and involve differential peripheral taste responsiveness. Strain differences in the consumption of some other sweet-tasting amino acids (glycine, l-alanine, l-glutamine, and l-threonine) do not depend on Tas1r3 polymorphisms and so must be due to allelic variation in other, as yet unknown, genes involved in sweet taste. Strain differences in the consumption of l-glutamate may depend on postingestive rather than taste mechanisms. Thus, genes and physiologic mechanisms responsible for strain differences in the consumption of each amino acid depend on the nature of its taste and postingestive properties. Overall, mouse strain differences in amino acid taste and appetite have a complex genetic architecture. In addition to the Tas1r3 gene, these differences depend on other genes likely involved in determining the taste and postingestive effects of amino acids. The identification of these genes may lead to the discovery of novel mechanisms that regulate amino acid taste and appetite.
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Abstract
From the age of 2 years, an American child is more likely to consume a sugar-sweetened product than a fruit or vegetable on any given day-a troubling statistic, given that food preferences are established early in childhood, as well as the strong association between this dietary pattern and increased risk of developing a number of chronic diseases. Here, we review the ontogeny and biopsychology of sweet taste, highlighting how a biological drive to prefer sweetness at high concentrations during childhood, which would have conferred an advantage in environments of scarcity, now predisposes children to overconsume all that is sweet in a modern food system replete with added sugars. We review the power of sweet taste to blunt expressions of pain and mask bad tastes in foods as well as factors that predispose some to consume high-sugar diets, including experiential learning and taste preferences driven in part by genetics. Understanding children's unique vulnerability to our current food environment, rich in both nutritive and nonnutritive sweeteners, is highlighted as a priority for future research to develop evidence-based strategies to help establish healthy dietary behaviors early in life.
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Douglas JE, Saunders CJ, Reed DR, Cohen NA. A role for airway taste receptor modulation in the treatment of upper respiratory infections. Expert Rev Respir Med 2016; 10:157-70. [PMID: 26731661 DOI: 10.1586/17476348.2016.1135742] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Taste receptors, initially identified in the oral epithelium, have since been shown to be widely distributed, being found in the upper and lower respiratory tracts, gastrointestinal epithelium, thyroid, and brain. The presence of taste receptors in the nasal epithelium has led to the discovery of their role in innate immunity, defending the paranasal sinuses against pathogens. This article addresses the current paradigm for understanding the role of extraoral taste receptors, specifically the T2R38 bitter taste receptor and the T1R2+3 sweet taste receptor, in respiratory innate defenses and presents evidence for the use of these and other taste receptors as therapeutic targets in the management of chronic rhinosinusitis. Future studies should focus on understanding the polymorphisms of taste receptors beyond T2R38 to fully elucidate their potential therapeutic use and lay the groundwork for their modulation in a clinical setting to decrease the health impact and economic burden of upper respiratory disease.
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Joseph PV, Reed DR, Mennella JA. Individual Differences Among Children in Sucrose Detection Thresholds: Relationship With Age, Gender, and Bitter Taste Genotype. Nurs Res 2016; 65:3-12. [PMID: 26633761 PMCID: PMC4679349 DOI: 10.1097/nnr.0000000000000138] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Little research has focused on whether there are individual differences among children in their sensitivity to sweet taste and, if so, the biological correlates of such differences. OBJECTIVES Our goal was to understand how variations in children's sucrose detection thresholds relate to their age and gender, taste genotype, body composition, and dietary intake of added sugars. METHODS Sucrose detection thresholds in 7- to 14-year-old children were tested individually using a validated, two-alternative, forced-choice, paired-comparison tracking method. Five genetic variants of taste genes were assayed: TAS1R3 and GNAT3 (sweet genes; one variant each) and the bitter receptor gene TAS2R38 (three variants). All children were measured for body weight and height. A subset of these children were measured for the percentage of body fat and waist circumference and provided added sugar intake by 24-hour dietary recall. RESULTS Sucrose thresholds ranged from 0.23 to 153.8 mM with most of the children completing the threshold task (216/235; 92%). Some children were biologically related (i.e., siblings), and for the genetic analysis, one sibling from each family was studied. Variants in the bitter but not the sweet genes were related to sucrose threshold and sugar intake; children with two bitter-sensitive alleles could detect sucrose at lower concentrations (F(2,165) = 4.55, p = .01; rs1726866) and reported eating more added sugar (% kcal; F(2, 62) = 3.64, p = .03) than did children with less sensitive alleles. Age, gender, and indices of obesity also were related to child-to-child differences in sucrose threshold; girls were more sensitive than boys (t(214) = 2.0, p = .05), older children were more sensitive than younger children (r(214) = -.16, p = .02), and fatter (r(84) = -.22, p = .05) or more centrally obese children (r(84) = -.26, p = .02) were more sensitive relative to others. DISCUSSION Inborn differences in bitter sensitivity may affect childhood dietary sugar intake with long-term health consequences. There may be a more complex interplay between the developing bitter and sweet taste systems than previously understood.
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Adappa ND, Workman AD, Hadjiliadis D, Dorgan DJ, Frame D, Brooks S, Doghramji L, Palmer JN, Mansfield C, Reed DR, Cohen NA. T2R38 genotype is correlated with sinonasal quality of life in homozygous ΔF508 cystic fibrosis patients. Int Forum Allergy Rhinol 2015; 6:356-61. [PMID: 26678226 DOI: 10.1002/alr.21675] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/15/2015] [Accepted: 10/04/2015] [Indexed: 12/17/2022]
Abstract
BACKGROUND Chronic rhinosinusitis (CRS) is very prevalent in the cystic fibrosis (CF) patient population, and leads to high morbidity and markedly decreased quality of life (QOL). Identification of genetic markers that contribute to CRS symptoms in these patients can allow for risk stratification and tailoring of medical and surgical treatments. T2R38 is a bitter taste receptor expressed in the sinonasal tract, and nonfunctional alleles of this receptor have been implicated in treatment-refractory CRS in non-CF patients. The purpose of this study is to investigate the significance of T2R38 genotype in the variability of sinonasal QOL and CRS disease severity in a sample of CF patients. METHODS ΔF508 homozygous CF patients were recruited from the University of Pennsylvania Cystic Fibrosis Center and were genotyped for the TAS2R38 locus. To assess sinonasal symptom severity, a 22-item Sino-Nasal Outcome Test (SNOT-22) was collected from each patient. Additional demographic and medical history data was obtained at the time of patient enrollment. RESULTS A total of 49 ΔF508 homozygous CF patients aged 18 to 32 years were included in the final SNOT-22 score analysis. Individuals with 2 functional T2R38 alleles (PAV/PAV) had significantly lower SNOT-22 scores (n = 49, p < 0.05). On further breakdown of SNOT-22 subcategories, rhinologic symptoms specifically were less severe in PAV/PAV patients than patients with other genotypes (n = 47, p < 0.05). CONCLUSION Our investigation indicates that T2R38 genotype correlates both with SNOT-22 scores and rhinologic-specific QOL in ΔF508 homozygous CF patients.
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Adappa ND, Farquhar D, Palmer JN, Kennedy DW, Doghramji L, Morris SA, Owens D, Mansfield C, Lysenko A, Lee RJ, Cowart BJ, Reed DR, Cohen NA. TAS2R38 genotype predicts surgical outcome in nonpolypoid chronic rhinosinusitis. Int Forum Allergy Rhinol 2015; 6:25-33. [PMID: 26562612 DOI: 10.1002/alr.21666] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 09/10/2015] [Accepted: 09/15/2015] [Indexed: 02/06/2023]
Abstract
BACKGROUND Over 550,000 sinus surgeries are performed annually in the United States on patients with chronic rhinosinusitis (CRS). Although the results of sinus surgery vary widely, no known genetic factor has been identified to predict surgical outcomes. The bitter taste receptor T2R38 has recently been demonstrated to regulate upper airway innate defense and may affect patient responses to therapy. Our goal was to determine whether TAS2R38 genetics predicts outcomes in CRS patients following sinus surgery. METHODS A prospective study of patients undergoing sinus surgery evaluating postoperative outcomes through the 22-item Sino-Nasal Outcome Test (SNOT-22). Patients were genotyped for TAS2R38. RESULTS A total of 123 patients with CRS were initially analyzed; 82 patients showed nasal polyps (CRSwNP) and 41 patients were without nasal polyps (CRSsNP). Six months after surgery, the overall SNOT-22 improvement was 25 ± 23 points. The TAS2R38 genotype was found to significantly correlate with surgical outcomes in patients without polyps; homozygotes for the functional receptor had a mean improvement of 38 ± 21, whereas heterozygotes or homozygotes for the nonfunctional receptor had a mean improvement of 12 ± 22 (p = 0.006). This result was confirmed with a multivariate regression that incorporated further patients with 1-month and 3-month scores (n = 207). CONCLUSION In patients undergoing sinus surgery for CRS, we have identified a genetic polymorphism that predicts variability in quality of life improvement following surgery at 6 months in nonpolypoid CRS. This is the first genetic polymorphism identified that has demonstrated to predict surgical outcome for a select group of CRS patients.
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Lin C, Fesi BD, Marquis M, Bosak NP, Theodorides ML, Avigdor M, McDaniel AH, Duke FF, Lysenko A, Khoshnevisan A, Gantick BR, Arayata CJ, Nelson TM, Bachmanov AA, Reed DR. Body Composition QTLs Identified in Intercross Populations Are Reproducible in Consomic Mouse Strains. PLoS One 2015; 10:e0141494. [PMID: 26551037 PMCID: PMC4638354 DOI: 10.1371/journal.pone.0141494] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 10/07/2015] [Indexed: 12/16/2022] Open
Abstract
Genetic variation contributes to individual differences in obesity, but defining the exact relationships between naturally occurring genotypes and their effects on fatness remains elusive. As a step toward positional cloning of previously identified body composition quantitative trait loci (QTLs) from F2 crosses of mice from the C57BL/6ByJ and 129P3/J inbred strains, we sought to recapture them on a homogenous genetic background of consomic (chromosome substitution) strains. Male and female mice from reciprocal consomic strains originating from the C57BL/6ByJ and 129P3/J strains were bred and measured for body weight, length, and adiposity. Chromosomes 2, 7, and 9 were selected for substitution because previous F2 intercross studies revealed body composition QTLs on these chromosomes. We considered a QTL confirmed if one or both sexes of one or both reciprocal consomic strains differed significantly from the host strain in the expected direction after correction for multiple testing. Using these criteria, we confirmed two of two QTLs for body weight (Bwq5-6), three of three QTLs for body length (Bdln3-5), and three of three QTLs for adiposity (Adip20, Adip26 and Adip27). Overall, this study shows that despite the biological complexity of body size and composition, most QTLs for these traits are preserved when transferred to consomic strains; in addition, studying reciprocal consomic strains of both sexes is useful in assessing the robustness of a particular QTL.
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Lei W, Ravoninjohary A, Li X, Margolskee RF, Reed DR, Beauchamp GK, Jiang P. Functional Analyses of Bitter Taste Receptors in Domestic Cats (Felis catus). PLoS One 2015; 10:e0139670. [PMID: 26488302 PMCID: PMC4619199 DOI: 10.1371/journal.pone.0139670] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 09/15/2015] [Indexed: 11/18/2022] Open
Abstract
Cats are obligate carnivores and under most circumstances eat only animal products. Owing to the pseudogenization of one of two subunits of the sweet receptor gene, they are indifferent to sweeteners, presumably having no need to detect plant-based sugars in their diet. Following this reasoning and a recent report of a positive correlation between the proportion of dietary plants and the number of Tas2r (bitter receptor) genes in vertebrate species, we tested the hypothesis that if bitter perception exists primarily to protect animals from poisonous plant compounds, the genome of the domestic cat (Felis catus) should have lost functional bitter receptors and they should also have reduced bitter receptor function. To test functionality of cat bitter receptors, we expressed cat Tas2R receptors in cell-based assays. We found that they have at least 7 functional receptors with distinct receptive ranges, showing many similarities, along with some differences, with human bitter receptors. To provide a comparative perspective, we compared the cat repertoire of intact receptors with those of a restricted number of members of the order Carnivora, with a range of dietary habits as reported in the literature. The numbers of functional bitter receptors in the terrestrial Carnivora we examined, including omnivorous and herbivorous species, were roughly comparable to that of cats thereby providing no strong support for the hypothesis that a strict meat diet influences bitter receptor number or function. Maintenance of bitter receptor function in terrestrial obligate carnivores may be due to the presence of bitter compounds in vertebrate and invertebrate prey, to the necessary role these receptors play in non-oral perception, or to other unknown factors. We also found that the two aquatic Carnivora species examined had fewer intact bitter receptors. Further comparative studies of factors driving numbers and functions of bitter taste receptors will aid in understanding the forces shaping their repertoire.
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Mennella JA, Roberts KM, Mathew PS, Reed DR. Children's perceptions about medicines: individual differences and taste. BMC Pediatr 2015; 15:130. [PMID: 26391354 PMCID: PMC4578784 DOI: 10.1186/s12887-015-0447-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 09/09/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bitter taste receptors are genetically diverse, so children likely vary in sensitivity to the "bad" taste of some pediatric formulations. Based on prior results that variation in a bitter taste receptor gene, TAS2R38, was related to solid (pill) formulation usage, we investigated whether this variation related to liquid formulation usage and young children's reports of past experiences with medicines and whether maternal reports of these past experiences were concordant with those of their children. METHODS We conducted retrospective interviews of 172 children 3 to 10 years old and their mothers (N = 130) separately in a clinical research setting about issues related to medication usage. Children were genotyped for the TASR38 variant A49P (alanine to proline at position 49). Children's responses were compared with their TAS2R38 genotype and with maternal reports. RESULTS Children (>4 years) reported rejecting medication primarily because of taste complaints, and those with at least one sensitive TAS2R38 allele (AP or PP genotype) were more likely to report rejecting liquid medications than were those without a taster allele (AA genotype; χ(2) = 5.72, df = 1, p = 0.02). Children's and mothers' reports of the children's past problems with medication were in concordance (p = 0.03). CONCLUSIONS Individual differences in taste responses to medications highlight the need to consider children's genetic variation and their own perceptions when developing formulations acceptable to the pediatric palate. Pediatric trials could systematically collect valid information directly from children and from their caregivers regarding palatability (rejection) issues, providing data to develop well-accepted pediatric formulations that effectively treat illnesses for all children. TRIAL REGISTRATION Clinicaltrials.gov protocol registration system (NCT01407939). Registered 19 July 2011.
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Rejniak KA, Lloyd MC, Reed DR, Bui MM. Diagnostic assessment of osteosarcoma chemoresistance based on Virtual Clinical Trials. Med Hypotheses 2015; 85:348-54. [PMID: 26130106 PMCID: PMC4549200 DOI: 10.1016/j.mehy.2015.06.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 05/28/2015] [Accepted: 06/17/2015] [Indexed: 01/03/2023]
Abstract
Osteosarcoma is the most common primary bone tumor in pediatric and young adult patients. Successful treatment of osteosarcomas requires a combination of surgical resection and systemic chemotherapy, both neoadjuvant (prior to surgery) and adjuvant (after surgery). The degree of necrosis following neoadjuvant chemotherapy correlates with the subsequent probability of disease-free survival. Tumors with less than 10% of viable cells after treatment represent patients with a more favorable prognosis. However, being able to predict early, such as at the time of the pre-treatment tumor biopsy, how the patient will respond to the standard chemotherapy would provide an opportunity for more personalized patient care. Patients with unfavorable predictions could be studied in a protocol, rather than a standard setting, towards improving therapeutic success. The onset of necrotic cells in osteosarcomas treated with chemotherapeutic agents is a measure of tumor sensitivity to the drugs. We hypothesize that the remaining viable cells, i.e., cells that have not responded to the treatment, are chemoresistant, and that the pathological characteristics of these chemoresistant tumor cells within the osteosarcoma pre-treatment biopsy can predict tumor response to the standard-of-care chemotherapeutic treatment. This hypothesis can be tested by comparing patient histopathology samples before, as well as after treatment to identify both morphological and immunochemical cellular features that are characteristic of chemoresistant cells, i.e., cells that survived treatment. Consequently, using computational simulations of dynamic changes in tumor pathology under the simulated standard of care chemotherapeutic treatment, one can couple the pre- and post-treatment morphological and spatial patterns of chemoresistant cells, and correlate them with patient clinical diagnoses. This procedure, that we named 'Virtual Clinical Trials', can serve as a potential predictive biomarker providing a novel value-added decision support tool for oncologists.
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Cornelis MC, Byrne EM, Esko T, Nalls MA, Ganna A, Paynter N, Monda KL, Amin N, Fischer K, Renstrom F, Ngwa JS, Huikari V, Cavadino A, Nolte IM, Teumer A, Yu K, Marques-Vidal P, Rawal R, Manichaikul A, Wojczynski MK, Vink JM, Zhao JH, Burlutsky G, Lahti J, Mikkilä V, Lemaitre RN, Eriksson J, Musani SK, Tanaka T, Geller F, Luan J, Hui J, Mägi R, Dimitriou M, Garcia ME, Ho WK, Wright MJ, Rose LM, Magnusson PKE, Pedersen NL, Couper D, Oostra BA, Hofman A, Ikram MA, Tiemeier HW, Uitterlinden AG, van Rooij FJA, Barroso I, Johansson I, Xue L, Kaakinen M, Milani L, Power C, Snieder H, Stolk RP, Baumeister SE, Biffar R, Gu F, Bastardot F, Kutalik Z, Jacobs DR, Forouhi NG, Mihailov E, Lind L, Lindgren C, Michaëlsson K, Morris A, Jensen M, Khaw KT, Luben RN, Wang JJ, Männistö S, Perälä MM, Kähönen M, Lehtimäki T, Viikari J, Mozaffarian D, Mukamal K, Psaty BM, Döring A, Heath AC, Montgomery GW, Dahmen N, Carithers T, Tucker KL, Ferrucci L, Boyd HA, Melbye M, Treur JL, Mellström D, Hottenga JJ, Prokopenko I, Tönjes A, Deloukas P, Kanoni S, Lorentzon M, Houston DK, Liu Y, Danesh J, Rasheed A, Mason MA, Zonderman AB, Franke L, Kristal BS, Karjalainen J, Reed DR, Westra HJ, Evans MK, Saleheen D, Harris TB, Dedoussis G, Curhan G, Stumvoll M, Beilby J, Pasquale LR, Feenstra B, Bandinelli S, Ordovas JM, Chan AT, Peters U, Ohlsson C, Gieger C, Martin NG, Waldenberger M, Siscovick DS, Raitakari O, Eriksson JG, Mitchell P, Hunter DJ, Kraft P, Rimm EB, Boomsma DI, Borecki IB, Loos RJF, Wareham NJ, Vollenweider P, Caporaso N, Grabe HJ, Neuhouser ML, Wolffenbuttel BHR, Hu FB, Hyppönen E, Järvelin MR, Cupples LA, Franks PW, Ridker PM, van Duijn CM, Heiss G, Metspalu A, North KE, Ingelsson E, Nettleton JA, van Dam RM, Chasman DI. Genome-wide meta-analysis identifies six novel loci associated with habitual coffee consumption. Mol Psychiatry 2015; 20:647-656. [PMID: 25288136 PMCID: PMC4388784 DOI: 10.1038/mp.2014.107] [Citation(s) in RCA: 184] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Revised: 07/17/2014] [Accepted: 07/22/2014] [Indexed: 02/02/2023]
Abstract
Coffee, a major dietary source of caffeine, is among the most widely consumed beverages in the world and has received considerable attention regarding health risks and benefits. We conducted a genome-wide (GW) meta-analysis of predominately regular-type coffee consumption (cups per day) among up to 91,462 coffee consumers of European ancestry with top single-nucleotide polymorphisms (SNPs) followed-up in ~30 062 and 7964 coffee consumers of European and African-American ancestry, respectively. Studies from both stages were combined in a trans-ethnic meta-analysis. Confirmed loci were examined for putative functional and biological relevance. Eight loci, including six novel loci, met GW significance (log10Bayes factor (BF)>5.64) with per-allele effect sizes of 0.03-0.14 cups per day. Six are located in or near genes potentially involved in pharmacokinetics (ABCG2, AHR, POR and CYP1A2) and pharmacodynamics (BDNF and SLC6A4) of caffeine. Two map to GCKR and MLXIPL genes related to metabolic traits but lacking known roles in coffee consumption. Enhancer and promoter histone marks populate the regions of many confirmed loci and several potential regulatory SNPs are highly correlated with the lead SNP of each. SNP alleles near GCKR, MLXIPL, BDNF and CYP1A2 that were associated with higher coffee consumption have previously been associated with smoking initiation, higher adiposity and fasting insulin and glucose but lower blood pressure and favorable lipid, inflammatory and liver enzyme profiles (P<5 × 10(-8)).Our genetic findings among European and African-American adults reinforce the role of caffeine in mediating habitual coffee consumption and may point to molecular mechanisms underlying inter-individual variability in pharmacological and health effects of coffee.
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Abstract
This article summarizes new knowledge about the contribution of genetic variation to person-to-person differences underlying some sensory aspects of dietary fatty acids. Receptors on the taste cells of the human tongue arise from genes that have marked variation in DNA sequence, which, in some cases, is associated with differences in how these lipids in foods are perceived. These perceptual differences may affect food selection.
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Mennella JA, Reed DR, Mathew PS, Roberts KM, Mansfield CJ. "A spoonful of sugar helps the medicine go down": bitter masking by sucrose among children and adults. Chem Senses 2014; 40:17-25. [PMID: 25381313 DOI: 10.1093/chemse/bju053] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Sweeteners are often added to liquid formulations of drugs but whether they merely make them better tasting or actually reduce the perception of bitterness remains unknown. In a group of children and adults, we determined whether adding sucrose to urea, caffeine, denatonium benzoate, propylthiouracil (PROP), and quinine would reduce their bitterness using a forced-choice method of paired comparisons. To better understand individual differences, adults also rated each solution using a more complex test (general Labeled Magnitude Scale [gLMS]) and were genotyped for the sweet taste receptor gene TAS1R3 and the bitter receptor TAS2R38. Sucrose suppressed the bitterness of each agent in children and adults. In adults, sucrose was effective in reducing the bitterness ratings from moderate to weak for all compounds tested, but those with the sensitive form of the sweet receptor reported greater reduction for caffeine and quinine. For PROP, sucrose was most effective for those who were genetically the most sensitive, although this did not attain statistical significance. Not only is the paired comparison method a valid tool to study how sucrose improves the taste of pediatric medicines among children but knowledge gleaned from basic research in bitter taste and how to alleviate it remains an important public health priority.
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Mennella JA, Reed DR, Roberts KM, Mathew PS, Mansfield CJ. Age-related differences in bitter taste and efficacy of bitter blockers. PLoS One 2014; 9:e103107. [PMID: 25050705 PMCID: PMC4106902 DOI: 10.1371/journal.pone.0103107] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 06/10/2014] [Indexed: 11/18/2022] Open
Abstract
Background Bitter taste is the primary culprit for rejection of pediatric liquid medications. We probed the underlying biology of bitter sensing and the efficacy of two known bitter blockers in children and adults. Methods A racially diverse group of 154 children (3-10 years old) and their mothers (N = 118) evaluated the effectiveness of two bitter blockers, sodium gluconate (NaG) and monosodium glutamate (MSG), for five food-grade bitter compounds (quinine, denatonium benzoate, caffeine, propylthiouracil (PROP), urea) using a forced-choice method of paired comparisons. The trial was registered at clinicaltrials.gov (NCT01407939). Results The blockers reduced bitterness in 7 of 10 bitter-blocker combinations for adults but only 3 of 10 for children, suggesting that efficacy depends on age and is also specific to each bitter-blocker combination. Only the bitterness of urea was reduced by both blockers in both age groups, whereas the bitterness of PROP was not reduced by either blocker in either age group regardless of TAS2R38 genotype. Children liked the salty taste of the blocker NaG more than did adults, but both groups liked the savory taste of MSG equally. Conclusions and Relevance Bitter blocking was less effective in children, and the efficacy of blocking was both age and compound specific. This knowledge will pave the way for evidence-based strategies to help develop better-tasting medicines and highlights the conclusion that adult panelists and genotyping alone may not always be appropriate in evaluating the taste of a drug geared for children.
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Jiang P, Josue-Almqvist J, Jin X, Li X, Brand JG, Margolskee RF, Reed DR, Beauchamp GK. The bamboo-eating giant panda (Ailuropoda melanoleuca) has a sweet tooth: behavioral and molecular responses to compounds that taste sweet to humans. PLoS One 2014; 9:e93043. [PMID: 24671207 PMCID: PMC3966865 DOI: 10.1371/journal.pone.0093043] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 02/28/2014] [Indexed: 12/18/2022] Open
Abstract
A growing body of behavioral and genetic information indicates that taste perception and food sources are highly coordinated across many animal species. For example, sweet taste perception is thought to serve to detect and motivate consumption of simple sugars in plants that provide calories. Supporting this is the observation that most plant-eating mammals examined exhibit functional sweet perception, whereas many obligate carnivores have independently lost function of their sweet taste receptors and exhibit no avidity for simple sugars that humans describe as tasting sweet. As part of a larger effort to compare taste structure/function among species, we examined both the behavioral and the molecular nature of sweet taste in a plant-eating animal that does not consume plants with abundant simple sugars, the giant panda (Ailuropoda melanoleuca). We evaluated two competing hypotheses: as plant-eating mammals, they should have a well-developed sweet taste system; however, as animals that do not normally consume plants with simple sugars, they may have lost sweet taste function, as has occurred in strict carnivores. In behavioral tests, giant pandas avidly consumed most natural sugars and some but not all artificial sweeteners. Cell-based assays revealed similar patterns of sweet receptor responses toward many of the sweeteners. Using mixed pairs of human and giant panda sweet taste receptor units (hT1R2+gpT1R3 and gpT1R2+hT1R3) we identified regions of the sweet receptor that may account for behavioral differences in giant pandas versus humans toward various sugars and artificial sweeteners. Thus, despite the fact that the giant panda's main food, bamboo, is very low in simple sugars, the species has a marked preference for several compounds that taste sweet to humans. We consider possible explanations for retained sweet perception in this species, including the potential extra-oral functions of sweet taste receptors that may be required for animals that consume plants.
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