| Abstract: | The PROP taste phenotype varies greatly among individuals, influencing eating behavior and therefore may
play a role in body composition. This variation is associated with polymorphisms in the bitter receptor gene
TAS2R38 and the taste-bud trophic factor gustin gene. The aim of this study was to examine the relationship
between TAS2R38 haplotypes and the gustin gene polymorphism rs2274333 in modulating PROP taste
phenotype. PROP phenotype was determined in seventy-six volunteers (29 males, 47 females, age 25±3 y)
by scaling methods and threshold measurements. TAS2R38 and gustin gene genotyping was performed using
PCR techniques. The lowest responsiveness in PROP nontasters is strongly associated with the AVI nontasting
TAS2R38 variant and the highest responsiveness in supertasters is strongly associated to allele A and genotype
AA of the gustin gene. These data support the hypothesis that the greater sensitivity of supertasters could be
mediated by a greater taste-bud density. Polymorphisms in TAS2R38 and gustin gene, together, accounted for
up to 60% of the phenotypic variance in PROP bitterness and to 40% in threshold values. These data, suggest
that other unidentified factors may bemore relevant for detecting low concentrations of PROP. Moreover, the
presence of the PAV variant receptor may be important for detecting high concentrations of PROP, whereas
the presence of allele A in gustin polymorphism may be relevant for perceiving low concentrations. These data
show how the combination of the TAS2R38 and gustin gene genotypes modulate PROP phenotype, providing
an additional tool for the evaluation of human eating behavior and nutritional status |
