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Taste Exam: A Brief and Validated Test
Published on: August 17, 2018
Genetic, functional, and phenotypic diversity in TAS2R38-mediated bitter taste perception
Maik Behrens1, Howard C Gunn, Purita C M Ramos
1Department of Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, Nuthetal 14558, Germany.
Chemical Senses
|May 2, 2013
Summary
Genetic variations in the TAS2R38 bitter taste receptor influence taste perception and related behaviors. This study explored additional TAS2R38 genetic diversity, revealing a range of functional responses and associations with taste detection thresholds.
Area of Science:
- Genetics
- Sensory Science
- Human Physiology
Background:
- The TAS2R38 bitter taste receptor gene exhibits known functional polymorphisms (PAV and AVI alleles) influencing taste perception of compounds like PTC and PROP.
- These TAS2R38 variations are linked to complex traits including diet choice and smoking habits.
- The functional significance of other extensive TAS2R38 polymorphisms remains largely unexplored.
Purpose of the Study:
- To investigate the genetic diversity and functional significance of additional polymorphisms within the TAS2R38 gene.
- To analyze allele-specific responses to various TAS2R38 agonists.
- To assess genotype-phenotype associations with taste detection thresholds.
Main Methods:
- Whole-gene sequencing of TAS2R38 in 56 Caucasian subjects to identify genetic variations.
- In vitro functional assays to measure allele-specific responses to five TAS2R38 agonists (PTC, PROP, goitrin, methimazole, sinigrin).
- Statistical analysis to correlate identified genotypes and haplotypes with threshold taste detection phenotypes.
Main Results:
- Sequencing identified three single-nucleotide substitutions (C145G/P49A, C785T/A262V, A886G/I296V) forming six haplotypes in the sample.
- In vitro assays demonstrated a continuous spectrum of functional responses across different TAS2R38 alleles.
- Significant associations were found between single nucleotide polymorphisms and PAV/AVI haplotypes and taste detection thresholds (P < 0.002 and P < 0.001, respectively).
Conclusions:
- TAS2R38 harbors diverse genetic variations that contribute to a range of bitter taste perception.
- While common PAV and AVI haplotypes show clear phenotypic associations, other identified haplotypes may be phenotypically relevant in different populations due to varying frequencies.
- Further research is warranted to elucidate the functional roles of rare TAS2R38 alleles in diverse global populations.
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