File:Neural tube - SHH model.jpg

Working model for the provision of positional identity by Shh signalling

(A) A Shh induced negative feedback loop involving Gli mediated transcriptional induction of the Shh receptor Ptc1 produces a temporally dynamic output of Gli activity in response to fixed Shh input.

(B) A state space model of ventral neural tube patterning. The range of time (x-axis) and levels (y-axis) of Gli activity necessary to induce each positional identity (p0–p3 and pMN) are illustrated by the coloured regions on the graph. This indicates that more ventral progenitor identities require higher levels and longer durations of Gli activity. On to this state space representation, the profile of Gli activity generated by different concentrations of Shh is indicated by the black lines. The incrementally thicker lines represent the profile generated by increasingly higher concentrations of Shh. The diagram shows how the differing profiles of Gli activity generate different positional identities in a progressive manner in the neural tube.

(C) Positional information corresponds to the time integral of Gli activity. The time integral of Gli activity, equivalent to the area under the curves in (B), provides the correlate of positional information. Increasingly more ventral progenitors are generated at correspondingly higher time integrals of Gli activity.

Figure 6 Pbio.1000382.g006.jpg

Reference

Dessaud E, Ribes V, Balaskas N, Yang LL, Pierani A, Kicheva A, Novitch BG, Briscoe J & Sasai N. (2010). Dynamic assignment and maintenance of positional identity in the ventral neural tube by the morphogen sonic hedgehog. PLoS Biol. , 8, e1000382. PMID: 20532235 DOI.

PLoS Biol. 2010 June; 8(6): e1000382. Published online 2010 June 1. doi: 10.1371/journal.pbio.1000382.

Copyright

Dessaud et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Cite this page: Hill, M.A. (2024, April 27) Embryology Neural tube - SHH model.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Neural_tube_-_SHH_model.jpg

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