Somites Without a Clock
Somites Without a Clock
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DOI：
10.1126/science.1247575
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发表时间：
2014-02-14
期刊：
影响因子：
56.9
通讯作者：
Stern, Claudio D.
中科院分区：
文献类型：
--
作者：
Dias, Ana S.;de Almeida, Irene;Stern, Claudio D.
脊椎动物胚胎体节的形成伴随着分子振荡（体节钟）。这种振荡器与沿着体轴沿着传播的波的相互作用（时钟和波前模型）通常被认为控制体节的数量、大小和轴向身份。在这里，我们表明，一个时钟和波前机制是不必要的体节的形成。用Noggin处理的非体节中胚层产生同时形成的许多体节，而没有Notch途径基因的循环表达，但具有正常的大小、形状和命运。这些体节具有轴向的同一性：Hox密码是固定的，独立于体节的命运。然而，这些体节没有被细分为吻侧和尾侧的一半，这是必要的神经分割。我们认为体节是一种自组织结构，其大小和形状受局部细胞间相互作用的控制。
The formation of body segments (somites) in vertebrate embryos is accompanied by molecular oscillations (segmentation clock). Interaction of this oscillator with a wave traveling along the body axis (the clock-and-wavefront model) is generally believed to control somite number, size, and axial identity. Here we show that a clock-and-wavefront mechanism is unnecessary for somite formation. Non-somite mesoderm treated with Noggin generates many somites that form simultaneously, without cyclic expression of Notch-pathway genes, yet have normal size, shape, and fate. These somites have axial identity: The Hox code is fixed independently of somite fate. However, these somites are not subdivided into rostral and caudal halves, which is necessary for neural segmentation. We propose that somites are self-organizing structures whose size and shape is controlled by local cell-cell interactions.