Neural crest cell migration: requirements for exogenous fibronectin and high cell density

Area of Science:

• Developmental Biology
• Cell Biology
• Biochemistry

Background:

• Neural crest cells are vital for embryonic development, involving extensive migration.
• Fibronectin (FN) has been indirectly implicated in neural crest cell migration.
• Direct experimental evidence for FN's role in neural crest cell adhesion and migration was lacking.

Purpose of the Study:

• To directly investigate the role of fibronectin (FN) in avian trunk neural crest cell adhesion and migration.
• To determine the influence of different substrates on neural crest cell behavior.
• To understand the impact of cell density on directional migration.

Main Methods:

• Utilized in vitro model systems with purified plasma FN and cellular FN substrates.
• Tested neural crest cell adhesion to various substrates including glass, collagen, and laminin (LN).
• Employed antibodies against FN's cell-binding region to inhibit and reverse migration, and manipulated cell densities.

Main Results:

• Avian trunk neural crest cells strongly adhered to FN substrates, with adhesion inhibited by anti-FN antibodies.
• Cells showed significantly less adhesion to LN, but epithelioid-phenotype cells bound equally to FN and LN.
• Migration rates were higher on FN than LN or collagen; cells preferentially migrated on FN when offered a choice.
• Migration on FN was random at low densities but directional at high densities, with in vitro rates matching in vivo observations.

Conclusions:

• Fibronectin (FN) plays a critical role in both neural crest cell adhesion and migration.
• Substrate composition and cell-cell interactions (density) significantly influence migration patterns.
• High neural crest cell densities within narrow migratory pathways are essential for effective directional migration in vivo.