Journal of Neuroscience, Vol 13, 1498-1510, Copyright © 1993 by Society for Neuroscience
Developmental expression of TERM-1 glycoprotein on growth cones and terminal arbors of individual identified neurons in the grasshopper
T Meier, S Therianos, D Zacharias and H Reichert
Department of Zoology, University of Basel, Switzerland.
The chemoaffinity theory postulates the existence of cell-specific
molecular signals that uniquely identify individual developing neurons.
Such molecules are thought to promote both accurate axon outgrowth and the
formation of correct synaptic connections. To identify candidates for such
neuron-specific recognition molecules, we generated monoclonal antibodies
that recognize surface-associated antigens expressed by individual
identified neurons in the grasshopper embryo. Here we report on a molecular
label that is expressed exclusively by two pairs of sibling interneurons in
the developing CNS. Our experiments indicate that during axogenesis, this
molecule is expressed at the surface of the growth cones of these cells,
while during subsequent synaptogenesis, it becomes concentrated at the
cells' developing terminal arbors. In both cases the molecule appears to be
secreted by the labeled structures. This molecule, which we call TERM-1, is
a glycoprotein with a molecular weight of approximately 48 kDa. The highly
restricted spatiotemporal expression pattern of TERM-1 implies that
individual developing neurons can acquire and retain unique molecular
labels that may be important for neuron-specific outgrowth and target
recognition.