Monoclonal antibody 2G13, a new axonal growth cone marker

Growth cones are specialized sensorimotor structures at the tips of neurites implicated in pathfinding decisions and axonal outgrowth during neuronal development. We generated a mouse monoclonal antibody (mAb 2G13) against chick tectum and found that the antibody exclusively labelled axonal growth cones, particularly their filopodia and lamellipodia, in developing rat CNS and in embryonic neurons in culture. The high fidelity of the staining of growth cones by mAb 2G13 means that the antibody will be a useful marker for identifying growth cones. In growth cones of cultured neurons, mAb 2G13 labelling is intracellular and mainly associated with the filamentous actin cytoskeleton. Experiments with cytochalasins, which depolymerise filamentous actin, showed that 2G13p (the protein recognised by mAb 2G13) is physically associated with filamentous actin in growth cones. These properties of 2G13p suggest a role in growth cone motility.