Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka-city, Fukuoka, 812-8582, Japan; Laboratory of Functional Anatomy, Graduate School of Biosource and Bioenvironmental Science, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka-city, Fukuoka, 819-0395, Japan.
Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka-city, Fukuoka, 812-8582, Japan.
Biochem Biophys Res Commun. 2021 Jun 11;557:206-212. doi: 10.1016/j.bbrc.2021.04.022. Epub 2021 Apr 16.
Taste buds are complex sensory organs embedded in the epithelium of fungiform papillae (FP) and circumvallate papillae (CV). The sweet, bitter, and umami tastes are sensed by type II taste cells that express taste receptors (Tas1rs and Tas2rs) coupled with the taste G-protein α-gustducin. Recent studies revealed that the taste response profiles of α-gustducin-expressing cells are different between FP and CV, but which genes could generate such distinctive cell characteristics are still largely unknown. We performed a comprehensive transcriptome analysis on α-gustducin-expressing cells in mouse FP and CV by single-cell RNA sequencing combined with fluorescence-activated cell sorting. Transcriptome profiles of the α-gustducin-expressing cells showed various expression patterns of taste receptors. Our clustering analysis defined the specific cell populations derived from FP or CV based on their distinct gene expression. Immunohistochemistry confirmed the specific expression of galectin-3, encoded by Lgals3, which was recognized as a differentially expressed gene in the transcriptome analysis. Our work provides fundamental knowledge toward understanding the genetic heterogeneity of type II cells, potentially revealing differential characterization of FP and CV taste bud cells.
味蕾是嵌入菌状乳头（FP）和轮廓乳头（CV）上皮中的复杂感觉器官。II 型味觉细胞感知甜味、苦味和鲜味，这些细胞表达与味觉 G 蛋白 α- gustducin 偶联的味觉受体（Tas1rs 和 Tas2rs）。最近的研究表明，α- gustducin 表达细胞在 FP 和 CV 之间的味觉反应谱不同，但哪些基因可以产生这种独特的细胞特征在很大程度上仍不清楚。我们通过单细胞 RNA 测序结合荧光激活细胞分选，对小鼠 FP 和 CV 中的 α- gustducin 表达细胞进行了全面的转录组分析。α- gustducin 表达细胞的转录组谱显示出味觉受体的各种表达模式。我们的聚类分析根据其独特的基因表达，定义了源自 FP 或 CV 的特定细胞群体。免疫组织化学证实了半乳糖凝集素-3（由 Lgals3 编码）的特异性表达，该基因在转录组分析中被识别为差异表达基因。我们的工作为理解 II 型细胞的遗传异质性提供了基础知识，可能揭示了 FP 和 CV 味蕾细胞的不同特征。
