EMBL Australia, Australian Regenerative Medicine Institute, Monash University, Building 75, Clayton, Victoria 3800, Australia.
Nature. 2011 May 26;473(7348):532-5. doi: 10.1038/nature09970. Epub 2011 May 15.
How dynamic signalling and extensive tissue rearrangements interact to generate complex patterns and shapes during embryogenesis is poorly understood. Here we characterize the signalling events taking place during early morphogenesis of chick skeletal muscles. We show that muscle progenitors present in somites require the transient activation of NOTCH signalling to undergo terminal differentiation. The NOTCH ligand Delta1 is expressed in a mosaic pattern in neural crest cells that migrate past the somites. Gain and loss of Delta1 function in neural crest modifies NOTCH signalling in somites, which results in delayed or premature myogenesis. Our results indicate that the neural crest regulates early muscle formation by a unique mechanism that relies on the migration of Delta1-expressing neural crest cells to trigger the transient activation of NOTCH signalling in selected muscle progenitors. This dynamic signalling guarantees a balanced and progressive differentiation of the muscle progenitor pool.
在胚胎发生过程中，动态信号和广泛的组织重排如何相互作用以产生复杂的模式和形状，目前还了解甚少。在这里，我们描述了小鸡骨骼肌肉早期形态发生过程中发生的信号事件。我们表明，存在于体节中的肌肉祖细胞需要 NOTCH 信号的短暂激活才能进行终末分化。NOTCH 配体 Delta1 在迁移经过体节的神经嵴细胞中呈镶嵌模式表达。神经嵴中 Delta1 功能的获得和丧失改变了体节中的 NOTCH 信号，导致成肌发生延迟或过早。我们的结果表明，神经嵴通过一种独特的机制来调节早期肌肉形成，该机制依赖于表达 Delta1 的神经嵴细胞的迁移，以触发选定的肌肉祖细胞中 NOTCH 信号的短暂激活。这种动态信号保证了肌肉祖细胞库的平衡和渐进分化。
