Actin cortex and microtubular system in morphogenesis: cooperation and competition

Area of Science:

• Cell Biology
• Cytoskeletal Dynamics
• Morphogenesis

Background:

• The cytoplasm's organization is governed by cytoskeletal networks, primarily actin cortex and microtubules.
• Cooperation and competition between these systems generate diverse cellular forms.
• Actin cortex alone can form functional units called actinoplasts.

Purpose of the Study:

• To investigate the roles of actin cortex and microtubules in cytoplasmic organization and morphogenesis.
• To explore the formation and behavior of actinoplasts and tubuloplasts.
• To understand how external factors influence cytoskeletal organization.

Main Methods:

• Induction of cytoplasmic segregation using tetradecanoyl phorbol-acetate (TPA) in fibroblasts.
• Analysis of actinoplast self-organization and microfilament bundle formation.
• Microscopical examination of cytoskeletal dynamics during cell spreading.
• Investigation of environmental factor effects, including cell-cell contact.

Main Results:

• Actin cortex alone organizes vectorized pseudopod-forming units (actinoplasts).
• Reversible segregation into actinoplasts and microtubule-rich tubuloplasts is crucial for morphogenesis.
• Actinoplast patterns depend on actin cortex tension, stabilized by microtubules.
• Environmental factors, like cell-cell contact, control pseudopodial activity.
• Cytoskeletal elements differentially affect intermediate filament distribution.

Conclusions:

• Actin cortex and microtubules are key determinants of cytoplasmic organization and cell shape.
• The interplay between actinoplasts and tubuloplasts is fundamental to morphogenesis.
• Environmental cues dynamically regulate cytoskeletal functions and cell behavior.