Influence of janusin and tenascin on growth cone behavior in vitro.

摘要: Janusin and tenascin are glia-derived, structurally related, extracellular matrix glycoproteins of the J1 family that expressed in vivo at times locations where active neurite outgrowth occurs, but also when formation or stabilization cytoarchitectonic boundaries appears to be operation. To resolve this apparent functional dichotomy, we have studied behavioral response growth cones, growing culture on permissive substrate laminin, janusin tenascin, by video time lapse microscopy. When were offered as sharp boundaries, dorsal root ganglion (DRG) retinal neuron cones avoided these molecules, not induced collapse. On other hand, offered, a mixture with uniform substrates, DRG displayed collapsed morphology able advance faster rate than laminin alone. In contrast, was completely inhibited under conditions, underscoring cell type specificity molecules. Using several monoclonal antibodies binding distinct epitopes molecule, identified two domains responsible for cone repulsion, epidermal factor (EGF)-like repeats 3-5 fibronectin III homologous 4 5. These different from one previously recognized involved substrate. We conclude both molecules may promote retard advance, depending spatial expression pattern neuronal type. © 1993 Wiley-Liss, Inc.