Somitogenesis, critical slowing down and the robustness of development

by David Bensimon

École Normale Supérieure & UCLA
at Physics Colloquium

Mon, 09 May 2022, 16:10
Ilse Katz Institute for Nanoscale Science & Technology (51), room 015


Somitogenesis, the segmentation of the antero-posterior axis in vertebrates, is thought to result from the interactions between a genetic oscillator and a posterior-moving determination wavefront. I will introduce the current state of knowledge of that important stage in the development of vertebrate embryos. Surprisingly while the oscillator period is very sensitive to temperature changes, the size of the segments is not.

I will show that the wavefront position is determined by the gradient of a morphogen (Fgf8) field. The velocity of that front is set by the ratio between the morphogen diffusion length and the typical time scale of Fgf8 decay. This velocity is temperature dependent and varies similarly as the oscillator frequency. In fact all time dependent transcripts vary as the oscillator period, i.e. as 1/(T-Tc) with Tc ~ 14.4°C. This suggests that somitogenesis might display critical slowing which may account for the temperature independence of somitogenesis.

Surprisingly similar temperature dependence is observed in the development of many organisms from C-elegans to fly, which might point to a very old origin for this critical mechanism dating to the Cambrian explosion, 540 MY ago.

*** Refreshments will be served from 15:50 ***

Created on 01-05-2022 by Kats, Yevgeny (katsye)
Updaded on 01-05-2022 by Kats, Yevgeny (katsye)