Final answer:
Antibodies to fibronectin inhibit the movement of neural crest cells during embryonic development, disrupting their migration. Fibronectin aids in cell adhesion to the ECM, which is essential for guiding the cells to their destinations. Exposure to such antibodies does not lead to cell division, death, or conversion to muscle cells, but specifically hampers migration.
Step-by-step explanation:
If antibodies to fibronectin are exposed to an embryo through which neural crest cells are migrating, the movement of these cells would be inhibited. Fibronectin is a critical component of the extracellular matrix (ECM) that facilitates cell adhesion and migration during embryonic development. Specifically, fibronectin binds to integrins on the cell surface, which allows the cells to attach to the ECM. In the context of neural crest cell migration, fibronectin acts as a pathfinder - it guides the cells to their appropriate destinations by providing a substrate for migration. Antibodies to fibronectin would disrupt this interaction, leading to an inhibition of neural crest cell movement. It is important for these cells to migrate properly as they differentiate to form many structures, including parts of the peripheral nervous system and craniofacial components.
Neural crest cells originate from the border of the neural tube and ectoderm during the early stages of embryogenesis. After the neural tube closes, these cells differentiate and migrate to various parts of the embryo. They do not divide uncontrollably as cancer cells would, they do not die upon exposure to fibronectin antibodies during migration, nor do they convert into muscle cells as a direct effect of antibody exposure. Proper signaling, facilitated by proteins like fibronectin in the ECM, is essential for the orderly differentiation and migration of neural crest cells.