Temporal dynamics of BMP/Nodal ratio drive tissue-specific gastrulation morphogenesis

Area of Science:

• Developmental Biology
• Cell Biology
• Genetics

Background:

• Vertebrate anteroposterior axis elongation relies on convergence and extension (C&E) movements in mesoderm and neuroectoderm.
• The molecular regulation of C&E across different tissues is not fully understood.

Purpose of the Study:

• To investigate whether molecular regulation of C&E differs between neuroectoderm and mesoderm.
• To identify the signaling pathways and temporal dynamics that control tissue-specific C&E.

Main Methods:

• Utilized a zebrafish explant model to study anteroposterior axis extension.
• Employed precise temporal manipulation of Bone Morphogenetic Protein (BMP) and Nodal signaling pathways.
• Observed C&E in intact zebrafish gastrulae.

Main Results:

• Demonstrated that neuroectoderm and mesoderm C&E can be uncoupled ex vivo.
• Identified a critical developmental window where BMP/Nodal ratios dictate tissue-specific C&E.
• Showed that increased BMP activity specifically enhances ectodermal C&E in vivo.

Conclusions:

• Temporal dynamics of BMP and Nodal signaling activate distinct morphogenetic programs for C&E.
• These findings reveal tissue-specific regulation of gastrulation movements.
• Highlights the importance of signaling timing in developmental processes.