Microsurgical Manipulations to Isolate Collectively Migrating Mesendoderm

Area of Science:

• Developmental Biology
• Cell Biology
• Biophysics

Background:

• Mesendoderm mantle closure in Xenopus laevis embryos is a key gastrulation event.
• Mesenchymal tissues, unlike epithelial tissues, lack tight junctions, yet mesendoderm cells migrate collectively.
• Xenopus mesendoderm cells are large, motile, and undertake significant migratory paths during development.

Purpose of the Study:

• To provide a protocol for preparing mesendoderm tissue explants and windowed embryos.
• To enable the study of collective cell behaviors in a mesenchymal context.
• To facilitate high-resolution imaging of cellular structures during migration.

Main Methods:

• Microsurgical preparation of mesendoderm tissue explants.
• Preparation of 'windowed' Xenopus embryos.
• Culture of mesendoderm on rigid substrates for enhanced visualization.

Main Results:

• Mesendoderm cells cultured on glass substrates exceed 100 µm in length.
• These cells display highly persistent leading lamellipodia, extending over 20 µm.
• The large size and migratory behavior allow visualization of polarized adhesive and cytoskeletal structures.

Conclusions:

• The Xenopus mesendoderm provides a unique system for investigating collective cell migration in mesenchymal tissues.
• The described protocols facilitate detailed analysis of cellular dynamics and structures.
• This model system is valuable for understanding fundamental principles of cell motility and tissue morphogenesis.