Robust axis elongation by a Nodal-dependent restriction of BMP signaling

Date

Jun 27, 2023

Time

11:30 AM - 12:30 PM

Speaker

Alexandra Schauer

Affiliation

Institute of Science and Technology Austria (ISTA)

Language

en

Main Topic

Biologie

Host

Jesse Veenvliet

Description

Embryogenesis is brought about by the coordinated activities of different signaling pathways controlling cell fate specification and morphogenesis. In vertebrate gastrulation, both Nodal and BMP signaling play key functions in germ layer specification and morphogenesis. Yet, how these pathways function in concert to render embryo patterning and morphogenesis so robust that key developmental processes unfold relatively normally even outside of the full embryonic context, is still not sufficiently understood. By analyzing ex vivo axis elongation in zebrafish embryonic explants, we show that Nodal signaling not only triggers axis elongation by induction of mesendodermal progenitors but also suppresses BMP signaling activity at the site of mesendoderm induction and thus explant elongation. Ectopic BMP signaling in the mesendoderm blocks cell alignment along the main explant axis and oriented mesendoderm intercalations, key processes to drive explant elongation. Translating these ex vivo observations to the intact zebrafish embryo showed that, similar to explants, Nodal signaling renders the dorsal domain less sensitive towards BMP signaling to allow effective cell intercalations, thereby conferring robustness to embryonic axis elongation. These findings suggest a dual function of Nodal signaling in embryonic axis extension by both inducing mesendoderm and maintaining low levels of BMP signaling activity in the dorsal portion of the mesendoderm.

Last modified: Jun 28, 2023, 7:35:49 AM