The mechanism of sudden stripe formation during dorso-ventral patterning in Drosophila
The mechanism of sudden stripe formation during dorso-ventral patterning in Drosophila
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DOI：
10.1007/s00285-006-0047-5
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发表时间：
2007-02-01
影响因子：
1.9
通讯作者：
Gaglia, Giorgio
中科院分区：
文献类型：
--
作者：
Iber, Dagmar;Gaglia, Giorgio
节肢动物和脊索动物的前部和后部(分别是腹部和背部)在早期胚胎发育过程中由高度保守的机制定义[de Robertis和Kuroda in Annu]。牧师单元格开发比奥尔。20、285-308(2004)]。一个重要的特征是突然形成一个狭窄的信号中线峰值。数学模型有助于提高我们对潜在机制的理解[Eldar等人。《自然》419(6904)，304-308(2002)；水谷在Dev.细胞8(6)，915-924(2005)；Shimmi等人。牢房120(6)，873-886，(2005)]。特别是，最新的模型表明，形态原的扩散和受体依赖的降解，以及蛋白酶介导的形态原载体蛋白的切割，足以突然产生尖锐的中线峰值[Dev中的Mizutani。牢房8(6)、915-924(2005)]。然而，这些过程如何产生观察到的模式，以及模型对参数值的变化有多敏感，还没有通过这项数值研究来解决。通过对模型的详细分析，我们发现信号峰的突然形成是背侧结构域形态原-载体复合体梯度倒置的结果。结果，配体突然被输送到中线而不是中线外，形成中线峰值。我们进一步证明，突变峰的形成需要一个由SOG和TSG组成的双组分载流子复合体。我们推导出峰形成的时间和浓度的定量条件。我们将受体浓度、配体产量和降解率以及载体产量、扩散和裂解速率确定为模型敏感的参数。数值研究证实了我们的分析。
The front and back (ventral and dorsal part respectively) of arthropods and chordates are defined by a highly conserved mechanism during early embryonic development [De Robertis and Kuroda in Annu. Rev. Cell Dev. Biol. 20, 285-308 (2004)]. An important feature is the sudden formation of a narrow midline peak of signaling. Mathematical models have helped to improve our understanding of the underlying mechanism [Eldar et al. in Nature 419(6904), 304-308 (2002); Mizutani in Dev. Cell 8(6), 915-924 (2005); Shimmi et al. in Cell 120(6), 873-886, (2005)]. In particular, the most recent model shows that diffusion and receptor-dependent degradation of the morphogen together with protease-mediated cleavage of a carrier protein for the morphogen are sufficient for the sudden generation of a sharp midline peak [Mizutani in Dev. Cell 8(6), 915-924 (2005)]. How these processes give rise to the observed pattern and how sensitive the model is to changes in parameter values has, however, not been resolved by this numerical study. By analysing the model in detail, we find that the sudden formation of a signaling peak is the consequence of the inversion of the gradient of the morphogen-carrier complex in the dorsal domain. As a consequence ligand is suddenly transported into rather than out of the midline, and a midline peak forms. We further show that a two-component carrier complex, consisting of Sog and Tsg, is required for abrupt peak formation. We derive quantitative conditions for the time and concentration at which the peak forms. We identify the receptor concentration, the ligand production and degradation rates, and the carrier production, diffusion, and cleavage rates as parameters to which the model is sensitive. Numerical studies confirm our analysis.