The clock and wavefront model revisited
The clock and wavefront model revisited
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DOI：
10.1016/j.jtbi.2011.05.004
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发表时间：
2011-08-21
影响因子：
2
通讯作者：
Baker, Ruth E.
中科院分区：
文献类型：
--
作者：
Murray, Philip J.;Maini, Philip K.;Baker, Ruth E.
目前接受的解释的时钟和波阵面模型的体节发生是一个向后移动的分子梯度依次减慢时钟振荡的速率，导致在空间读出的时间振荡。然而，虽然分子组成的时钟和波前现在已经确定在前体中胚层（PSM），还没有确凿的证据表明，所观察到的分子波前的作用，以减缓时钟振荡。在这里，我们提出了一种替代配方的时钟和波前模型中，振荡器耦合，已经知道在振荡器同步中发挥关键作用，起着根本性的重要作用，振荡沿着的前后（AP）轴减慢。我们的模型有三个参数，可以确定，在任何给定的物种，通过测量三个数量：时钟周期在后PSM，体节长度和长度的PSM。一个行进的波前，减缓振荡沿着AP轴，是一个新兴的功能的模型。使用该模型，我们预测：（a）基因表达的移动条纹之间的距离;（B）基因表达的移动条纹的数量;以及（c）沿着AP轴的振荡器周期分布。使用现有的斑马鱼数据进行验证的条纹数据的预测。我们模拟了一系列的实验扰动，并演示了如何使用该模型来明确定义一个参考系沿着AP轴。比较斑马鱼，小鸡，小鼠和蛇的数据，我们证明：（a）图案配置文件的变化是由一个单一的无量纲参数占耦合强度的比例;和（B）的周期配置文件沿着AP轴是跨物种的保守。因此，该模型是一致的想法，虽然在PSM模式传播所涉及的基因各不相同，有一个保守的跨物种的模式化机制。(C)2011爱思唯尔有限公司版权所有。
The currently accepted interpretation of the clock and wavefront model of somitogenesis is that a posteriorly moving molecular gradient sequentially slows the rate of clock oscillations, resulting in a spatial readout of temporal oscillations. However, while molecular components of the clocks and wavefronts have now been identified in the pre-somitic mesoderm (PSM), there is not yet conclusive evidence demonstrating that the observed molecular wavefronts act to slow clock oscillations. Here we present an alternative formulation of the clock and wavefront model in which oscillator coupling, already known to play a key role in oscillator synchronisation, plays a fundamentally important role in the slowing of oscillations along the anterior-posterior (AP) axis. Our model has three parameters which can be determined, in any given species, by the measurement of three quantities: the clock period in the posterior PSM, somite length and the length of the PSM. A travelling wavefront, which slows oscillations along the AP axis, is an emergent feature of the model. Using the model we predict: (a) the distance between moving stripes of gene expression; (b) the number of moving stripes of gene expression and (c) the oscillator period profile along the AP axis. Predictions regarding the stripe data are verified using existing zebrafish data. We simulate a range of experimental perturbations and demonstrate how the model can be used to unambiguously define a reference frame along the AP axis. Comparing data from zebrafish, chick, mouse and snake, we demonstrate that: (a) variation in patterning profiles is accounted for by a single nondimensional parameter; the ratio of coupling strengths; and (b) the period profile along the AP axis is conserved across species. Thus the model is consistent with the idea that, although the genes involved in pattern propagation in the PSM vary, there is a conserved patterning mechanism across species. (C) 2011 Elsevier Ltd. All rights reserved.