大鼠牙胚发育过程中釉原蛋白含量在空间和时间上的变化

目的:研究随着大鼠牙胚的发育，釉原蛋白(Am)在空间和时间上的变化。方法：以重组、纯化的大鼠釉原蛋白为抗原。混入完全/不完全弗氏佐剂，免疫新西兰大白兔；用双向免疫扩散法到抗体效价，将获得的多克隆抗血清经硫酸胺初步纯化后，用Western blot和免疫组化检测大鼠牙胚Am的组织表达特异性。结果：Western blot显示：在大鼠牙胚组织总蛋白中有特异性表达，而在肝、脑、肾组织中没有表达。免疫组化检测，在成釉细胞和发育早期的釉基质中有Am的表达，而在成牙本质细胞和成熟牙釉质、牙本质中无表达。结论：釉原蛋白的表达具有严格的空间和时间依赖性，在牙胚发育早期高表达而在发育后期和已矿化期表达低或无表达。

SPATIAL-AND TEMPORAL-RESTRICTED PATTERN OF AMELOGENIN(AM) DURING RAT TOOTH ORGANOGENESIS

Objective: To examine the synthesis and secretion of enamel protein by ameloblasts in their early stages of development.Methods: We prepared a rabbit anti-rat Am IgG to immunized the rabbit with recombinant Am. The specific IgG antibody was further purified with sulfuric acetate.Total protein isolated from rat tooth germ and brain, liver and kidney were used to proceed Western blotting study. The Amelogenin (Am) of rat tooth germ were detected by immunohistochemical method.Results: Western blotting were negative in brain, liver and kidney and there was a specific band in tooth germ. The observation of immunohistochemical method showed amelogenin occurs as early as the polarization stage of pre-ameloblasts, expressed at a low level in post-secretary stages of amelogenesis and odontoblast do not transcribe the amelogenin.Conclusions:It indicates that instructive interactions provide position- and time-dependent signal restricting the express of Am.