Developmental regulation and ultrastructure of glycogen deposits during murine tooth morphogenesis
Developmental regulation and ultrastructure of glycogen deposits during murine tooth morphogenesis
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小鼠牙齿形态发生过程中糖原沉积的发育调节和超微结构
DOI：
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发表时间：
1999
影响因子：
3.6
通讯作者：
I. Thesleff
中科院分区：
文献类型：
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作者：
H. Ohshima;J. Wartiovaara;I. Thesleff
摘要应用组织化学PAS染色和透射电镜观察了小鼠牙胚中糖原沉积的分布和超微结构。 在胚胎11.5-17天（E11.5-E17）的小鼠胚胎和出生后2天（P2）小鼠中检查了下第一磨牙和上第一磨牙。在牙齿形态发生过程中，口腔和牙齿上皮细胞和间充质细胞普遍呈PAS阳性。PAS-阴性细胞存在于E13在牙芽上皮的远端和接触间充质，这种完全缺乏PAS反应性继续在牙乳头间充质和内釉上皮在帽和钟阶段。在早期形态发生过程中，相互作用的上皮和间充质中缺乏糖原沉积可能与它们表现出的高信号活性有关。间充质细胞在牙囊一贯拥有小簇或大池的糖原，这消失了P2。由于强烈的PAS反应在未来的骨部位的间充质细胞中观察到，牙囊细胞中的糖原可能与它们发育成硬组织形成细胞有关。超微结构观察的釉器官细胞从帽到早期钟阶段（E14-E15）揭示了糖原池的发生，这是与高尔基体和囊泡具有无定形内容物。糖原颗粒也偶尔存在于囊泡内或细胞外基质中。这些可能与糖胺聚糖成分胞吐到细胞外空间和星网的形成有关。
Abstract The distribution and ultrastructure of glycogen deposits were investigated in the murine tooth germ by histochemical periodic acid-Schiff (PAS) staining and transmission electron microscopy. Lower and upper first molars were examined in mouse embryos at embryonic days 11.5–17 (E11.5–E17) and in 2-day-old postnatal (P2) mice. The oral and dental epithelia and the mesenchymal cells were generally PAS-positive during tooth morphogenesis. PAS-negative cells were present at E13 in the distal tip of the tooth bud epithelium and in the contacting mesenchyme, and this complete lack of PAS reactivity continued in the dental papilla mesenchyme and inner enamel epithelium during the cap and bell stages. The lack of glycogen deposits in the interacting epithelium and mesenchyme during early morphogenesis may be associated with their demonstrated high signaling activities. Mesenchymal cells in the dental follicle consistently possessed small clusters or large pools of glycogen, which disappeared by P2. Since an intense PAS reaction was seen in mesenchymal cells at future bone sites, the glycogen in the dental follicle cells may be associated with their development into hard-tissue-forming cells. Ultrastructural observation of the enamel organ cells from the cap to early bell stages (E14–E15) revealed the occurrence of glycogen pools, which were associated with the Golgi apparatus and with vesicles having amorphous contents. Glycogen particles were also occasionally present inside vesicles or in the extracellular matrix. These may be associated with the exocytosis of glycosaminoglycan components into extracellular spaces and the formation of the stellate reticulum.