Regulation of Nodal signaling propagation by receptor interactions and positive feedback
Abstract
During vertebrate embryogenesis, the germ layers are patterned by secreted Nodal signals. In the classical model, Nodals elicit signaling by binding to a complex comprising Type I/II Activin receptors (Acvr) and the co-receptor Tdgf1. However, it is currently unclear whether receptor binding can also affect the distribution of Nodals themselves through the embryo, and it is unknown which of the putative Acvr paralogs mediate Nodal signaling in zebrafish. Here, we characterize three Type I (Acvr1) and four Type II (Acvr2) homologs and show that - except for Acvr1c - all receptor-encoding transcripts are maternally deposited and present during zebrafish embryogenesis. We generated mutants and used them together with combinatorial morpholino knockdown and CRISPR F0 knockout (KO) approaches to assess compound loss-of-function phenotypes. We discovered that the Acvr2 homologs function partly redundantly and partially independently of Nodal to pattern the early zebrafish embryo, whereas the Type I receptors Acvr1b-a and Acvr1b-b redundantly act as major mediators of Nodal signaling. By combining quantitative analyses with expression manipulations, we found that feedback-regulated Type I receptors and co-receptors can directly influence the diffusion and distribution of Nodals, providing a mechanism for the spatial restriction of Nodal signaling during germ layer patterning.
Data availability
Figure 1 - Source Data, Figure 2 - Source Data, Figure 2 - Figure Supplement 1 - Source Data, Figure 2 - Figure Supplement 2 - Source Data, Figure 2 - Figure Supplement 3 - Source Data, Figure 3 - Source Data, Figure 3 - Figure Supplement 1 - Source Data, Figure 3 - Figure Supplement 2 - Source Data, Figure 3 - Figure Supplement 3 - Source Data, Figure 4 - Source Data, Figure 4 - Figure Supplement 1 - Source Data, Figure 5 - Source Data, Figure 6 - Source Data, Figure 6 - Figure Supplement 1 - Source Data and Figure 6 - Figure Supplement 2 - Source Data contain the numerical data used to generate the figures.
-
Baseline_expression_from_transcriptional_profiling_of_zebrafish_developmental_stagesEBI European Nucleotide Archive (accession no: PRJEB7244).
Article and author information
Author details
Funding
International Max Planck Research School From Molecules to Organisms"" (Graduate Student Fellowship)
- Hannes Preiß
- David Mörsdorf
- Patrick Müller
Max Planck Society (Max Planck Research Group)
- Patrick Müller
European Research Council (Grant agreement No 637840 (QUANTPATTERN))
- Patrick Müller
European Research Council (Grant agreement No 863952 (ACE-OF-SPACE))
- Patrick Müller
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Lilianna Solnica-Krezel, Washington University School of Medicine, United States
Ethics
Animal experimentation: All procedures were executed in accordance with the guidelines of the State of Baden-Württemberg and approved by the Regierungspräsidium Tübingen and the Regierungspräsidium Freiburg.
Version history
- Received: January 9, 2021
- Accepted: September 19, 2022
- Accepted Manuscript published: September 23, 2022 (version 1)
- Accepted Manuscript updated: October 5, 2022 (version 2)
- Version of Record published: October 27, 2022 (version 3)
Copyright
This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
Metrics
-
- 1,519
- views
-
- 327
- downloads
-
- 3
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Further reading
-
- Developmental Biology
We previously showed that SerpinE2 and the serine protease HtrA1 modulate fibroblast growth factor (FGF) signaling in germ layer specification and head-to-tail development of Xenopus embryos. Here, we present an extracellular proteolytic mechanism involving this serpin-protease system in the developing neural crest (NC). Knockdown of SerpinE2 by injected antisense morpholino oligonucleotides did not affect the specification of NC progenitors but instead inhibited the migration of NC cells, causing defects in dorsal fin, melanocyte, and craniofacial cartilage formation. Similarly, overexpression of the HtrA1 protease impaired NC cell migration and the formation of NC-derived structures. The phenotype of SerpinE2 knockdown was overcome by concomitant downregulation of HtrA1, indicating that SerpinE2 stimulates NC migration by inhibiting endogenous HtrA1 activity. SerpinE2 binds to HtrA1, and the HtrA1 protease triggers degradation of the cell surface proteoglycan Syndecan-4 (Sdc4). Microinjection of Sdc4 mRNA partially rescued NC migration defects induced by both HtrA1 upregulation and SerpinE2 downregulation. These epistatic experiments suggest a proteolytic pathway by a double inhibition mechanism:
SerpinE2 ┤HtrA1 protease ┤Syndecan-4 → NC cell migration.
-
- Developmental Biology
- Neuroscience
Human fetal development has been associated with brain health at later stages. It is unknown whether growth in utero, as indexed by birth weight (BW), relates consistently to lifespan brain characteristics and changes, and to what extent these influences are of a genetic or environmental nature. Here we show remarkably stable and lifelong positive associations between BW and cortical surface area and volume across and within developmental, aging and lifespan longitudinal samples (N = 5794, 4–82 y of age, w/386 monozygotic twins, followed for up to 8.3 y w/12,088 brain MRIs). In contrast, no consistent effect of BW on brain changes was observed. Partly environmental effects were indicated by analysis of twin BW discordance. In conclusion, the influence of prenatal growth on cortical topography is stable and reliable through the lifespan. This early-life factor appears to influence the brain by association of brain reserve, rather than brain maintenance. Thus, fetal influences appear omnipresent in the spacetime of the human brain throughout the human lifespan. Optimizing fetal growth may increase brain reserve for life, also in aging.