Barbarossa Iole Tomassini, Melis Melania, Mattes Mitchell Z, Calò Carla, Muroni Patrizia, Crnjar Roberto, Tepper Beverly J
Department of Biomedical Sciences, University of Cagliari, Monserrato, CA 09042, Italy.
Department of Biomedical Sciences, University of Cagliari, Monserrato, CA 09042, Italy; Department of Food Science, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ 08901-8520, USA.
Physiol Behav. 2015 Jan;138:6-12. doi: 10.1016/j.physbeh.2014.09.011. Epub 2014 Oct 17.
PROP responsiveness is associated with TAS2R38 haplotypes and fungiform papilla density. Recently, we showed that a polymorphism in the gene coding for the salivary trophic factor, gustin (CA6), affects PROP sensitivity by acting on cell growth and fungiform papillae maintenance, in a genetically homogeneous cohort. Since population homogeneity can lead to over estimation of gene effects, the primary aim of the present work was to confirm gustin's role in PROP bitterness intensity and fungiform papillae density in a genetically diverse population. Eighty subjects were genotyped for both genes by PCR techniques. PROP responsiveness was assessed by a filter paper method and fungiform papilla density was determined in each subject. As expected, PROP bitterness ratings were lower in individuals with the AVI/AVI diplotype of TAS2R38 than in individuals with PAV/PAV and PAV/AVI diplotypes. However, no differences in PROP bitterness among genotypes of the gustin gene, and no differences in the density of fungiform papillae related to TAS2R38 diplotype were found. In contrast, the density of fungiform papillae decreased as the number of minor (G) alleles at the gustin locus increased. In addition, the distribution of TAS2R38 genotypes within each gustin genotype group showed that the occurrence of recessive alleles at both loci was infrequent in the present sample compared to other populations. These findings confirm that papillae density is associated with gustin gene polymorphism, rs2274333 (A/G), in an ancestrally heterogeneous population, and suggest that variations in the frequency of allele combinations for these two genes could provide a salient explanation for discrepant findings for gustin gene effects across populations.
丙硫氧嘧啶（PROP）反应性与味觉感受器基因TAS2R38单倍型及菌状乳头密度相关。最近，我们发现，在一个基因同质的队列中，编码唾液营养因子味肽（CA6）的基因多态性通过作用于细胞生长和维持菌状乳头，影响PROP敏感性。由于群体同质性可能导致对基因效应的高估，本研究的主要目的是在一个基因多样化的群体中，确认味肽在PROP苦味强度和菌状乳头密度方面的作用。采用聚合酶链反应（PCR）技术对80名受试者的这两个基因进行基因分型。通过滤纸法评估PROP反应性，并测定每位受试者的菌状乳头密度。正如预期的那样，TAS2R38基因AVI/AVI双倍型个体的PROP苦味评分低于PAV/PAV和PAV/AVI双倍型个体。然而，未发现味肽基因各基因型之间的PROP苦味存在差异，也未发现与TAS2R38双倍型相关的菌状乳头密度存在差异。相反，随着味肽基因座上次要（G）等位基因数量的增加，菌状乳头密度降低。此外，每个味肽基因型组内TAS2R38基因型的分布表明，与其他群体相比，本样本中两个基因座隐性等位基因的出现频率较低。这些发现证实，在一个祖先异质的群体中，乳头密度与味肽基因多态性rs2274333（A/G）相关，并表明这两个基因等位基因组合频率的变化可以为不同群体中味肽基因效应的差异结果提供一个显著的解释。
