Building a Consistent Neuronetwork: Defining Molecular Cues Involved in the Synaptic Target Recognition of Drosophila Melanogaster

208 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2001.Every synaptogenesis begins with "synaptic target recognition", a cell-cell recognition event in which a neuron and its target stably adhere. Herein I describe two transmembrane molecules present on a subset of muscles in the Drosophila embryonic neuromuscular system, Fas3 and Toll, that affect this process in opposite ways. Fas3, an immunoglobulin molecule, is capable of homophilically inducing synaptic target recognition, while Toll, a leucine-rich repeat molecule, prevents the process. The effects of each protein, which are functionally disparate, can be summated by individual growth cones based upon the relative amounts of either cue present to arrive at a net synaptic decision. Both of these molecules act at the ultrastructural level to affect the presence of tight membrane-membrane apposition (focal adhesion) between neural and target membranes. In the case of Fas3, its promotion of adhesion is independent of its signaling capability, and this adhesion acts to permit an as yet unknown synaptic signaling cascade.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD