A self-generated Toddler gradient guides mesodermal cell migration

Area of Science:

• Developmental biology
• Cell migration
• Embryogenesis

Background:

• Germ layer formation during gastrulation requires precise cell movements.
• The guidance cues for long-range progenitor cell migration are not fully understood.
• Directional cell migration typically involves chemokine gradients from localized sources.

Purpose of the Study:

• To identify the guidance cues controlling zebrafish ventrolateral mesoderm migration during gastrulation.
• To elucidate the mechanism by which mesodermal cells achieve directed migration.
• To investigate the role of the protein Toddler and its receptor in embryonic development.

Main Methods:

• Utilized zebrafish as a model organism for studying gastrulation.
• Investigated the expression patterns of Toddler and its receptor during embryogenesis.
• Performed experiments to assess the function of the Apelin receptor in cell migration.
• Analyzed the formation and sensing of the Toddler gradient.

Main Results:

• Zebrafish ventrolateral mesoderm migration is guided by a self-generated gradient of Toddler/ELABELA/Apela.
• The Apelin receptor, expressed in mesodermal cells, acts as both a scavenger receptor to create the gradient and a chemokine receptor to sense it.
• This single receptor-based mechanism effectively steers mesodermal cell migration.

Conclusions:

• A novel self-generated gradient mechanism, mediated by a single receptor, guides mesodermal cell migration during zebrafish gastrulation.
• The Apelin receptor plays a dual role in gradient formation and sensing, providing a robust guidance system.
• This finding reveals an enigmatic guidance cue essential for navigating the complex embryonic environment.