NORMAL DEVELOPMENT OF THE SKELETON IN CHICK LIMB BUDS DEVOID OF DORSAL ECTODERM
NORMAL DEVELOPMENT OF THE SKELETON IN CHICK LIMB BUDS DEVOID OF DORSAL ECTODERM
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DOI：
10.1016/0012-1606(86)90091-6
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发表时间：
1986-11-01
影响因子：
2.7
通讯作者：
LEWIS, J
中科院分区：
文献类型：
--
作者：
MARTIN, P;LEWIS, J
有人认为肢芽背侧面和腹侧面上的外胚层在控制软骨分化模式中起作用。为了验证这一点，在肢芽发育的最初阶段，即鸡胚的背翅芽外胚层在第17-19阶段被紫外线照射破坏，但顶端外胚层嵴幸免。照射的外胚层在24小时内消失（阶段23-24），此后没有再生;因此，肢芽的背侧表面保持裸露的整个期间的骨骼图案形成。在照射后6或7天（第35阶段），当所有成体骨骼元素的雏形以可识别的形式正常存在时，受照射的翅膀可以分为两类，形状近似正常的翅膀和背侧卷曲的翅膀。与对照组相比，所有这些肢体的尺寸都不同程度地减小，并且缺乏背部软组织。然而，那些外形正常的肢体，尽管有时几乎整个背表面都裸露了，但几乎总是有一个完整的、比例正常的软骨结构，这表明外胚层（除了顶端外胚层嵴）对肢体软骨结构的发育没有任何直接的控制。然而，许多由于辐射而卷曲的肢体确实有重大的模式畸形，这表明软骨分化的拓扑结构确实取决于肢体芽的形状。
It has been suggested that the ectoderm on the dorsal and ventral faces of the limb bud plays a part in controlling the pattern of cartilage differentiation. To test this, the dorsal wing bud ectoderm in the chick embryo was destroyed by irradiation with ultraviolet light at stage 17-19, at the very beginning of limb bud development, but the apical ectodermal ridge was spared. The irradiated ectoderm disappeared within 24 hr (by stage 23-24) and did not regenerate thereafter; thus the dorsal surface of the limb bud was kept denuded throughoutmost of the period of skeletal pattern formation. By 6 or 7 days after the irradiation (stage 35), when the rudiments of all the adult skeletal elements are normally present in recognizable form, the irradiated wings could be placed into two categories, those that were approximately normal in shape and those that had curled dorsally. All of these limbs were reduced in size, to varying degrees, when compared to their controls and lacked dorsal soft tissues. The limbs that were normal in shape, however, even though sometimes denuded over practically the whole extent of their dorsal surface, almost always had a complete and normally proportioned cartilage pattern, suggesting that ectoderm (other than the apical ectodermal ridge) does not exert any direct control over the development of the limb cartilage pattern. However, many of those limbs that had curled as a result of the irradiation did have major pattern deformities, suggesting that the topology of cartilage differentiation does depend on the shape of the limb bud.