TAS2R38 is a human bitter receptor gene with a common but inactive allele; people homozygous for the inactive form cannot perceive low concentrations of certain bitter compounds. The frequency of the inactive and active forms of this receptor is nearly equal in many human populations, and heterozygotes with 1 copy of the active form and 1 copy of the inactive form have the most common diplotype. However, even though they have the same genotype, heterozygotes differ markedly in their perception of bitterness, perhaps in part because of differences in TAS2R38 mRNA expression. Other tissues express this receptor too, including the nasal sinuses, where it contributes to pathogen defense. We, therefore, wondered whether heterozygous people had a similar wide range of TAS2R38 mRNA in sinonasal tissue and whether those with higher TAS2R38 mRNA expression in taste tissue were similarly high expressers in nasal tissue. To that end, we measured gene expression by quantitative PCR in taste and sinonasal tissue and found that expression abundance in one tissue was not related to the other. We confirmed the independence of expression in other tissue pairs expressing TAS2R38 mRNA, such as pancreas and small intestine, using autopsy data from the Genotype-Tissue Expression project (although people with high expression of TAS2R38 mRNA in colon also tended to have higher expression in the small intestine). Thus, taste tissue TAS2R38 mRNA expression among heterozygotes is unlikely to predict expression in other tissues, perhaps reflecting tissue-dependent function, and hence regulation, of this protein.

中文翻译：

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组织依赖性表达的苦味受体TAS2R38 mRNA。

TAS2R38是具有共同但无活性等位基因的人类苦味受体基因；无活性形式纯合子的人不能感知到低浓度的某些苦味化合物。在许多人群中，该受体的失活和活跃形式的频率几乎相等，具有1个拷贝的活跃形式和1个拷贝的非活跃形式的杂合子具有最常见的双倍型。但是，即使它们具有相同的基因型，杂合子在苦味上也有明显差异，这可能部分是由于TAS2R38 mRNA表达的差异。其他组织也表达该受体，包括鼻窦，在此有助于病原体防御。因此，我们 想知道杂合子的人在鼻窦组织中是否具有类似的TAS2R38 mRNA广泛范围，以及味觉组织中具有较高TAS2R38 mRNA表达的人在鼻组织中是否同样具有高表达。为此，我们通过定量PCR测量了味觉和鼻窦组织中的基因表达，发现一种组织中的表达丰度与另一种组织无关。我们使用基因型组织表达项目的尸检数据证实了表达TAS2R38 mRNA的其他组织对的表达是独立的，例如胰腺和小肠（尽管结肠中TAS2R38 mRNA表达高的人也倾向于在结肠中表达更高）。小肠）。因此，杂合子中的味觉组织TAS2R38 mRNA表达不可能预测其他组织中的表达，