In the context of tissue development, Netrin-1 has roles in guiding what processes?

• A. DNA replication
• B. Cell migration and survival
• C. Protein synthesis
• D. Ion transport

Answer: (B)

Netrin-1 is a secreted guidance cue that helps shape tissue development by directing where cells move and whether they survive as they migrate. It forms gradients that cells detect through receptors such as DCC and UNC5. When netrin-1 binds DCC, migrating cells and growing axons are attracted toward higher concentrations, guiding proper pathfinding. Interaction with UNC5 can mediate repulsion or, depending on receptor context, promote survival signals, helping cells avoid apoptosis during morphogenesis. This combination of directing movement and supporting survival explains why its roles center on cell migration and survival rather than processes like DNA replication, protein synthesis, or ion transport.