Laboratory of Functional Anatomy, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Department of Food and Life Sciences, Ibaraki University, Ami, Japan.
Sci Rep. 2021 Jun 10;11(1):12318. doi: 10.1038/s41598-021-91728-9.
The characterization of molecular mechanisms underlying the taste-sensing system of chickens will add to our understanding of their feeding behaviors in poultry farming. In the mammalian taste system, the heterodimer of taste receptor type 1 members 1/3 (T1R1/T1R3) functions as an umami (amino acid) taste receptor. Here, we analyzed the expression patterns of T1R1 and T1R3 in the taste cells of chickens, labeled by the molecular markers for chicken taste buds (vimentin and α-gustducin). We observed that α-gustducin was expressed in some of the chicken T1R3-positive taste bud cells but rarely expressed in the T1R1-positive and T2R7-positive taste bud cells. These results raise the possibility that there is another second messenger signaling system in chicken taste sensory cells. We also observed that T1R3 and α-gustducin were expressed mostly in the vimentin-positive taste bud cells, whereas T1R1 and bitter taste receptor (i.e., taste receptor type 2 member 7, T2R7) were expressed largely in the vimentin-negative taste bud cells in chickens. In addition, we observed that T1R1 and T1R3 were co-expressed in about 5% of chickens' taste bud cells, which express T1R1 or T1R3. These results suggest that the heterodimer of T1R1 and T1R3 is rarely formed in chickens' taste bud cells, and they provide comparative insights into the expressional regulation of taste receptors in the taste bud cells of vertebrates.
鸡味觉感知系统的分子机制特征将有助于我们了解家禽养殖中的采食行为。在哺乳动物味觉系统中，味觉受体类型 1 成员 1/3（T1R1/T1R3）异二聚体作为鲜味（氨基酸）味觉受体发挥作用。在这里，我们分析了 T1R1 和 T1R3 在鸡味觉细胞中的表达模式，这些味觉细胞用鸡味蕾的分子标记（波形蛋白和α-味觉素）进行标记。我们观察到，α-味觉素在一些鸡 T1R3 阳性味觉细胞中表达，但在 T1R1 阳性和 T2R7 阳性味觉细胞中很少表达。这些结果表明，鸡味觉感觉细胞中可能存在另一种第二信使信号系统。我们还观察到，T1R3 和 α-味觉素主要在波形蛋白阳性的味觉细胞中表达，而 T1R1 和苦味受体（即味觉受体类型 2 成员 7，T2R7）主要在鸡的波形蛋白阴性味觉细胞中表达。此外，我们观察到，T1R1 和 T1R3 在大约 5%的表达 T1R1 或 T1R3 的鸡味觉细胞中共同表达。这些结果表明，T1R1 和 T1R3 的异二聚体在鸡的味觉细胞中很少形成，它们为脊椎动物味蕾细胞中味觉受体的表达调控提供了比较性的见解。
