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bioRxiv · 10.1101/505925

Dynamics of Spaetzle morphogen shuttling in the Drosophila embryo shapes pattern

Rahimi, N.·Averbukh, I.·Carmon, S.·Schejter, E. D.·Barkai, N.·Shilo, B.-Z.
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Abstract

Establishment of morphogen gradients in the early Drosophila embryo is challenged by a diffusible extracellular milieu, and rapid nuclear divisions that occur at the same time. To understand how a sharp gradient is formed within this dynamic environment, we followed the generation of graded nuclear Dorsal (Dl) protein, the hallmark of pattern formation along the dorso-ventral axis, in live embryos. We show that a sharp gradient is formed through extracellular, diffusion-based morphogen shuttling that progresses through several nuclear divisions. Perturbed shuttling in wntD mutant embryos results in a flat activation peak and aberrant gastrulation. Re-entry of Dl into the nuclei at each cycle refines the signaling output, by guiding graded accumulation of the T48 transcript that drives patterned gastrulation. We conclude that diffusion-based ligand shuttling, coupled with dynamic readout, establishes a refined pattern within the diffusible environment of early embryos.

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Rahimi, N., Averbukh, I., Carmon, S., Schejter, E. D., Barkai, N., Shilo, B.-Z.. 2018-12-26. Dynamics of Spaetzle morphogen shuttling in the Drosophila embryo shapes pattern. https://doi.org/10.1101/505925

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