PUBLICATION

The role of maternal Activin-like signals in zebrafish embryos

Authors

Hagos, E.G., Fan, X., and Dougan, S.T.

ID

ZDB-PUB-070820-1

Date

2007

Source

Developmental Biology 309(2): 245-258 (Journal)

Registered Authors

Dougan, Scott T., Fan, Xiang, Hagos, Engda

Keywords

Zebrafish, squint, Nodal-related proteins, Maternal, TGF-β, SB-505124, Mesoderm, Endoderm

MeSH Terms

Activins/genetics
Activins/metabolism*
Activin Receptors/genetics
Activin Receptors/metabolism
Signal Transduction
Body Patterning
Zebrafish Proteins/genetics
Zebrafish Proteins/metabolism*
Pyridines/pharmacology
Nodal Signaling Ligands
Mesoderm/embryology
Mesoderm/metabolism
Animals
Zebrafish/embryology
Zebrafish/metabolism*
Transforming Growth Factor beta/genetics
Transforming Growth Factor beta/metabolism
Transforming Growth Factor beta/physiology
Receptors, Transforming Growth Factor beta/antagonists & inhibitors
Receptors, Transforming Growth Factor beta/metabolism
Imidazoles/pharmacology
Benzodioxoles/pharmacology
Mutation
Endoderm/embryology
Endoderm/metabolism
Activin Receptors, Type I

(all 26)

PubMed

17692308 Full text @ Dev. Biol.

Abstract

Maternal Activin-like proteins, a subgroup of the TGF-beta superfamily, play a key role in establishing the body axes in many vertebrates, but their role in teleosts is unclear. At least two maternal Activin-like proteins are expressed in zebrafish, including the Vg1 orthologue, zDVR-1, and the nodal-related gene, Squint. Our analysis of embryos lacking both maternal and zygotic squint function revealed that maternal squint is required in some genetic backgrounds for the formation of dorsal and anterior tissues. Conditional inactivation of the ALK4, 5 and 7 receptors by SB-505124 treatment during the cleavage stages ruled out a role for maternal Squint, zDVR-1, or other Activin-like ligands before the mid-blastula transition, when the dorsal axis is established. Furthermore, we show that maternal Squint and zDVR-1 are not required during the cleavage stages to induce zygotic nodal-related gene expression. nodal-related gene expression decreases when receptor inhibition continues past the mid-blastula transition, resulting in a progressive loss of mesoderm and endoderm. We conclude that maternally expressed Activin-like signals do not act before the mid-blastula transition in zebrafish, but do have a variably penetrant role in the later stages of axis formation. This contrasts with the early role for these signals during Xenopus development.

Genes / Markers

Figures