Localization and quantitation of 125I-epidermal growth factor binding in mouse embryonic tooth and other embryonic tissues at different developmental stages.
Localization and quantitation of 125I-epidermal growth factor binding in mouse embryonic tooth and other embryonic tissues at different developmental stages.
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DOI：
10.1016/0012-1606(87)90117-5
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发表时间：
1987-03
影响因子：
2.7
通讯作者：
A. Partanen;Irma Thesleff
中科院分区：
文献类型：
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作者：
A. Partanen;Irma Thesleff
我们已经表明，表皮生长因子（EGF）抑制器官培养的小鼠胚胎牙齿的形态发生和细胞分化。这种抑制作用取决于牙齿发育的阶段，因此只有早期发育阶段的牙齿对EGF有反应（A-M。Partanen，P. Ekblom，and I. 03 The Dog（1985）111，84-94）。我们现在已经研究了EGF结合在牙齿在不同发育阶段的数量和模式，通过孵育解剖的牙胚与125 I标记的EGF。尽管每μ gDNA结合125 I-EGF的量保持在同一水平，但放射自显影定位显示结合位点的分布发生了显著变化。在芽期，侵入下层间充质的上皮牙芽具有EGF结合位点，但芽周围的牙间充质细胞的凝聚不结合EGF。在发育的帽状期，牙间充质结合EGF，但牙上皮不结合。这表明，牙齿间充质是EGF抑制早期帽状期牙齿形态发生的主要靶组织。在晚期形态发生过程中，EGF的结合位点也从牙乳头间充质中消失，但是由围绕牙胚的浓缩间充质细胞组成的牙囊大量结合EGF。我们还研究了EGF结合在其他胚胎器官，肾，唾液腺，肺和皮肤，这都是由间充质和上皮成分形成的发展。EGF结合在各种组织中的模式表明，EGF可能在上皮间充质器官的器官发生中起作用，在最初的上皮芽形成和分支形态发生期间作为上皮增殖的刺激物。这项研究的结果表明，在胚胎发育过程中，EGF刺激或维持未分化细胞的增殖，并且EGF受体在不同器官中的表达与胚胎的年龄无关，而是特定于每个器官的发育阶段。
We have shown earlier that epidermal growth factor (EGF) inhibits morphogenesis and cell differentiation in mouse embryonic teeth in organ culture. This inhibition depends on the stage of tooth development so that only teeth at early developmental stages respond to EGF (A-M. Partanen, P. Ekblom, and I. Thesleff (1985)Dev. Biol.111, 84–94). We have now studied the quantity and pattern of EGF binding in teeth at various stages of development by incubating the dissected tooth germs with125I-labeled EGF. Although the quantity of125I-EGF binding per μg DNA stays at the same level, localization of125I-EGF binding by autoradiography reveals that the distribution of binding sites changes dramatically. In bud stage the epithelial tooth bud that is intruding into the underlying mesenchyme has binding sites for EGF, but the condensation of dental mesenchymal cells around the bud does not bind EGF. At the cap stage of development the dental mesenchyme binds EGF, but the dental epithelium shows no binding. This indicates that the dental mesenchyme is the primary target tissue for the inhibitory effect of EGF on tooth morphogenesis during early cap stage. During advanced morphogenesis the binding sites of EGF disappear also from the dental papilla mesenchyme, but the dental follicle which consists of condensed mesenchymal cells surrounding the tooth germ, binds EGF abundantly. We have also studied EGF binding during the development of other embryonic organs, kidney, salivary gland, lung, and skin, which are all formed by mesenchymal and epithelial components. The patterns of EGF binding in various tissues suggest that EGF may have a role in the organogenesis of epitheliomesenchymal organs as a stimulator of epithelial proliferation during initial epithelial bud formation and branching morphogenesis. The results of this study indicate that EGF stimulates or maintains proliferation of undifferentiated cells during embryonic development and that the expression of EGF receptors in different organs is not related to the age of the embryo, but is specific to the developmental stage of each organ.