PUBLICATION

Receptor binding and tortuosity explain morphogen local-to-global diffusion coefficient transition

Authors
Zhu, S., Loo, Y.T., Veerapathiran, S., Loo, T.Y.J., Tran, B.N., Teh, C., Zhong, J., Matsudaira, P., Saunders, T.E., Wohland, T.
ID
ZDB-PUB-240727-10
Date
2024
Source
Biophysical journal : (Journal)
Registered Authors
Loo, Tricia, Saunders, Timothy Edward, Teh, Cathleen, Veerapathiran, Sapthaswaran, Wohland, Thorsten
Keywords
none
MeSH Terms
  • Zebrafish*/metabolism
  • Models, Biological
  • Animals
  • Diffusion
  • Protein Binding
  • Extracellular Space/metabolism
  • Brain/metabolism
PubMed
39049492 Full text @ Biophys. J.
Abstract
Morphogens are intercellular signaling molecules providing spatial information to cells in developing tissues to coordinate cell fate decisions. The spatial information is encoded within long-ranged concentration gradients of the morphogen. Direct measurement of morphogen dynamics in a range of systems suggests that local and global diffusion coefficients can differ by orders of magnitude. Further, local diffusivity can be large, which would potentially abolish any concentration gradient rapidly. Such observations have led to alternative transport models being proposed, including transcytosis and cytonemes. Here, we show that accounting for tissue architecture combined with receptor binding is sufficient to hinder the diffusive dynamics of morphogens, leading to an order of magnitude decrease in the effective diffusion coefficient from local to global scales. In particular, we built a realistic in silico architecture of the extracellular spaces of the zebrafish brain using light and electron microscopy data. Simulations on realistic architectures demonstrate that tortuosity and receptor binding within these spaces are sufficient to reproduce experimentally measured morphogen dynamics. Importantly, this work demonstrates that hindered diffusion is a viable mechanism for gradient formation, without requiring additional regulatory control.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping