Interpretation of the sonic hedgehog morphogen gradient by a temporal adaptation mechanism

@article{Dessaud2007InterpretationOT,
  title={Interpretation of the sonic hedgehog morphogen gradient by a temporal adaptation mechanism},
  author={Eric Dessaud and Lin Yang and Katy Hill and Barny Cox and Fausto Ulloa and Ana Ribeiro and Anita Mynett and Bennett G. Novitch and James Briscoe},
  journal={Nature},
  year={2007},
  volume={450},
  pages={717-720}
}
Morphogens act in developing tissues to control the spatial arrangement of cellular differentiation. The activity of a morphogen has generally been viewed as a concentration-dependent response to a diffusible signal, but the duration of morphogen signalling can also affect cellular responses. One such example is the morphogen sonic hedgehog (SHH). In the vertebrate central nervous system and limbs, the pattern of cellular differentiation is controlled by both the amount and the time of SHH… Expand
Establishing and interpreting graded Sonic Hedgehog signaling during vertebrate neural tube patterning: the role of negative feedback.
TLDR
Together, these mechanisms exemplify a strategy for morphogen interpretation, which is termed temporal adaptation that relies on the continuous processing and refinement of the cellular response to the graded signal. Expand
Notch Activity Modulates the Responsiveness of Neural Progenitors to Sonic Hedgehog Signaling
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It is demonstrated that Notch signaling plays an essential role in this process, enabling neural progenitors to attain sufficiently high levels of Shh pathway activity needed to direct the ventral-most cell fates. Expand
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The coordination of the patterning activity of Shh with tissue growth and cell differentiation is investigated and a high degree of conservation is discovered in pattern formation between mouse and chick, which supports a model in which progenitor cells respond to the cumulative amount of Gli activity. Expand
A homeodomain feedback circuit underlies step-function interpretation of a Shh morphogen gradient during ventral neural patterning
TLDR
It is established that dynamic, non-graded changes in responding cells are essential for Shh morphogen interpretation, and a rationale to explain mechanistically the phenomenon of cellular memory of morphogen exposure is provided. Expand
Morphogen interpretation: concentration, time, competence, and signaling dynamics
  • A. Sagner, J. Briscoe
  • Biology, Medicine
  • Wiley interdisciplinary reviews. Developmental biology
  • 2017
TLDR
Molecular mechanisms proposed in recent studies that explain how the response to morphogens is determined by differential competence, pathway intrinsic feedback, and the interpretation of signaling dynamics by gene regulatory networks are outlined. Expand
Ptch1 and Gli regulate Shh signalling dynamics via multiple mechanisms
TLDR
The Shh gradient in the developing mouse neural tube is quantified and it is shown that while the amplitude of the gradient increases over time, the activity of the pathway transcriptional effectors, Gli proteins, initially increases but later decreases. Expand
Gene Regulatory Logic for Reading the Sonic Hedgehog Signaling Gradient in the Vertebrate Neural Tube
TLDR
It is shown that a spatially and temporally changing gradient of Shh signaling is interpreted by the regulatory logic of a downstream transcriptional network that provides robustness and reliability to tissue patterning. Expand
Distinct Sonic Hedgehog signaling dynamics specify floor plate and ventral neuronal progenitors in the vertebrate neural tube.
TLDR
This work provides evidence supporting a common scheme for FP specification by Shh signaling that reconciles mechanisms of FP development in teleosts and amniotes and provides insight into how the dynamics of morphogen signaling are deployed to extend the patterning capacity of a single ligand. Expand
Morphogen interpretation in the developing nervous system
TLDR
The cis-regulatory modules of neural Shh-target genes are identified and the mechanisms imposed by Gli proteins, the bifunctional transcriptional mediators of Shh gradient are elucidated, which offers a fairly simple conceptual explanation for morphogen-mediated transcriptional regulation of neural-specific target genes during embryogenesis. Expand
Morphogen interpretation: the transcriptional logic of neural tube patterning.
TLDR
Recent studies involving genome wide analyses, functional experiments and theoretical models that have begun to characterise the molecular logic by which neural cells interpret Shh signalling suggest that cell identity results from the combined input of Shh signaling, uniformly expressed neural factors and the cross-regulatory network of downstream Shh target genes. Expand
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