Monoclonal antibody 2G13, a new axonal growth cone marker

Growth cones are specialized sensorimotor structures at the tips of neurite s implicated in pathfinding decisions and axonal outgrowth during neuronal development. We generated a mouse monoclonal antibody (mAb 2G13) against ch ick tectum and found that the antibody exclusively labelled axonal growth c ones, particularly their filopodia and lamellipodia, in developing rat CNS and in embryonic neurons in culture. The high fidelity of the staining of g rowth 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 la belling is intracellular and mainly associated with the filamentous actin c ytoskeleton. Experiments with cytochalasins, which depolymerise filamentous actin, showed that 2G13p (the protein recognised by mAb 2G13) is physicall y associated with filamentous actin in growth cones. These properties of 2G 13p suggest a role in growth cone motility.