The small GTPase Arf6 regulates sea urchin morphogenesis

Area of Science:

• Developmental Biology
• Cell Biology
• Molecular Biology

Background:

• The small GTPase Arf6 is a conserved protein involved in cytoskeletal actin remodeling and membrane trafficking.
• While Arf6's cellular functions are well-studied, its physiological role in embryonic development remains largely unknown.

Purpose of the Study:

• To investigate the function of Arf6 in mediating cellular morphogenesis during early sea urchin development.
• To dissect Arf6's role in the migration and differentiation of primary mesenchyme cells (PMCs) and endodermal cells.

Main Methods:

• Utilized loss-of-function morpholino injections to inhibit Arf6 activity.
• Employed a constitutively active Arf6-Q67L construct to study its gain-of-function effects.
• Focused on sea urchin embryos, specifically examining PMCs and endodermal cells.

Main Results:

• Arf6 is essential for skeleton formation and primary mesenchyme cell migration, attributed to its actin remodeling capabilities.
• Arf6 loss-of-function leads to gastrulation defects.
• Constitutively active Arf6 causes endodermal cell detachment and reduced cadherin staining, suggesting a role in cadherin recycling.

Conclusions:

• Arf6 plays a significant role in embryonic morphogenesis by regulating actin dynamics and cell-cell adhesion.
• Arf6 impacts coordinated cell movements critical for the formation of embryonic structures.
• Arf6's involvement in cadherin recycling is crucial for maintaining epithelial integrity during development.