Mammalian taste bud cells have a limited lifespan and differentiate into type I, II, and III cells from basal cells (type IV cells) (postmitotic precursor cells). However, little is known regarding the cell lineage within taste buds. In this study, we investigated the cell fate of Mash1-positive precursor cells utilizing the Cre-loxP system to explore the differentiation of taste bud cells. We found that Mash1-expressing cells in Ascl1CreERT2::CAG-floxed tdTomato mice differentiated into taste bud cells that expressed aromatic L-amino acid decarboxylase (AADC) and carbonic anhydrase IV (CA4) (type III cell markers), but did not differentiate into most of gustducin (type II cell marker)-positive cells. Additionally, we found that Mash1-expressing cells could differentiate into phospholipase C β2 (PLCβ2)-positive cells, which have a shorter lifespan compared with AADC- and CA4-positive cells. These results suggest that Mash1-positive precursor cells could differentiate into type III cells, but not into most of type II cells, in the taste buds.

中文翻译：

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Mash1 表达细胞可能与成年小鼠味蕾中的 III 型细胞和 PLCβ2 阳性细胞分化的子集有关

哺乳动物味蕾细胞的寿命有限，可从基底细胞（IV 型细胞）（有丝分裂后前体细胞）分化为 I、II 和 III 型细胞。然而，关于味蕾内的细胞谱系知之甚少。在这项研究中，我们利用 Cre-loxP 系统研究了 Mash1 阳性前体细胞的细胞命运，以探索味蕾细胞的分化。我们发现 Ascl1CreERT2::CAG-floxed tdTomato 小鼠中表达 Mash1 的细胞分化为表达芳香族 L-氨基酸脱羧酶 (AADC) 和碳酸酐酶 IV (CA4)（III 型细胞标记物）的味蕾细胞，但未分化进入大多数gustducin（II型细胞标志物）阳性细胞。此外，我们发现表达 Mash1 的细胞可以分化为磷脂酶 C β2 (PLCβ2) 阳性细胞，与 AADC 和 CA4 阳性细胞相比，它们的寿命较短。这些结果表明，Mash1 阳性前体细胞可以分化为味蕾中的 III 型细胞，但不能分化为大多数 II 型细胞。