Axis formation in annual killifish: Nodal and β-catenin regulate morphogenesis without Huluwa prepatterning.
Philip B AbituaLaura M StumpDeniz C AkselAlexander F SchierPublished in: Science (New York, N.Y.) (2024)
Axis formation in fish and amphibians typically begins with a prepattern of maternal gene products. Annual killifish embryogenesis, however, challenges prepatterning models as blastomeres disperse and then aggregate to form the germ layers and body axes. We show that huluwa , a prepatterning factor thought to break symmetry by stabilizing β-catenin, is truncated and inactive in Nothobranchius furzeri . Nuclear β-catenin is not selectively stabilized on one side of the blastula but accumulates in cells forming the aggregate. Blocking β-catenin activity or Nodal signaling disrupts aggregate formation and germ layer specification. Nodal signaling coordinates cell migration, establishing an early role for this signaling pathway. These results reveal a surprising departure from established mechanisms of axis formation: Huluwa-mediated prepatterning is dispensable, and β-catenin and Nodal regulate morphogenesis.
Keyphrases
- epithelial mesenchymal transition
- cell proliferation
- cell migration
- signaling pathway
- lymph node
- neoadjuvant chemotherapy
- induced apoptosis
- pi k akt
- cell cycle arrest
- gene expression
- radiation therapy
- pregnant women
- body mass index
- oxidative stress
- endoplasmic reticulum stress
- genome wide identification
- transcription factor
- preterm birth
- cell fate