- Open Access
Optimizing Information Transmission in Neural Induction Constrains Cell Surface Contacts of Ascidian Embryos
PRX Life 3, 033004 – Published 10 July, 2025
DOI: https://doi.org/10.1103/hskn-zdb1
Abstract
The onset of neural induction in the anterior ectoderm of ascidian embryos is regulated at the extracellular level by FGF signaling molecules, which control the acquisition of neural fate through the activation of the ERK pathway. Among the anterior ectoderm cells exposed to FGF, only a fraction will acquire neural fate. The selection of neural precursors depends on the quasi-invariant geometry of the embryo, which imposes upon each ectoderm cell a precise area of cell surface contact with underlying FGF-expressing (mesendoderm) cells. Here we investigate information transmission between FGF and activated ERK and how this depends on the geometry of the system. Optimizing information transmission with the constraint that the total FGF-emitting surface area is restricted, as in the embryo, we find that the surface contacts with FGF that maximize information transmission are close to those observed experimentally. This information optimal solution is compatible with the anterior ectoderm cells having different areas of cell surface exposure to FGF, allowing the embryo to use cell surface areas as a regulatory mechanism for differentiating the outcome of cells that sense a constant FGF concentration.
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- See Supplemental Material at http://link.aps.org/supplemental/10.1103/hskn-zdb1 for Fig. S1 comparison between the experimental data and the model in WT and ephrin inhibited embryos; Table S1 Experimental values of the total surfaces and surfaces exposed to FGF in aline cells; Fig. S2 (a) Independent cell case. (b) The role of the concavity of the information curve as a function of the constraint to determine whether the symmetric or asymmetric solution optimises information transmission; Fig. S3 (a) Information transmission in the absence of ephrin; (b) Influence of the position of the input distribution on information transmission; Fig. S4 two-cells, the asymmetrical case; Fig. S5 Fig. 4(e) with absolute values of the surfaces instead of the relative ones.
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