TY - JOUR T1 - Neuropil Pattern Formation and Regulation of Cell Adhesion Molecules in <em>Drosophila</em> Optic Lobe Development Depend on Synaptobrevin JF - The Journal of Neuroscience JO - J. Neurosci. SP - 7548 LP - 7556 DO - 10.1523/JNEUROSCI.19-17-07548.1999 VL - 19 IS - 17 AU - Peter Robin Hiesinger AU - Christian Reiter AU - Harald Schau AU - Karl-Friedrich Fischbach Y1 - 1999/09/01 UR - http://www.jneurosci.org/content/19/17/7548.abstract N2 - To investigate a possible involvement of synaptic machinery inDrosophila visual system development, we studied the effects of a loss of function of neuronal synaptobrevin, a protein required for synaptic vesicle release. Expression of tetanus toxin light chain (which cleaves neuronal synaptobrevin) and genetic mosaics were used to analyze neuropil pattern formation and levels of selected neural adhesion molecules in the optic lobe. We show that targeted toxin expression in the developing optic lobe results in disturbances of the columnar organization of visual neuropils and of photoreceptor terminal morphology. IrreC-rst immunoreactivity in neuropils is increased after widespread expression of toxin. In photoreceptors, targeted toxin expression results in increased Fasciclin II and chaoptin but not IrreC-rst immunoreactivity. Axonal pathfinding and programmed cell death are not affected. In genetic mosaics, patches of photoreceptors that lack neuronal synaptobrevin exhibit the same phenotypes observed after photoreceptor-specific toxin expression. Our results demonstrate the requirement of neuronal synaptobrevin for regulation of cell adhesion molecules and development of the fine structure of the optic lobe. A possible causal link to fine-tuning processes that may include synaptic plasticity in the development of the Drosophila CNS is discussed. ER -