Exploring the Role of MicroRNA in Synaptic Growth and Development in the Drosophila NMJ

Saturday, October 29, 2011
Hall 1-2 (San Jose Convention Center)
Julia Garcia , Division of Medical Sciences, Harvard Medical School, Boston, MA
Elizabeth McNeill, PhD , Cell Biology, Harvard Medical School, Boston, MA
David Van Vactor, PhD , Cell Biology, Harvard Medical School, Boston, MA
Understanding the normal formation, growth and development of synapses is fundamental to gaining insight into neurological disorders where these processes are disrupted such as Fragile X mental retardation, Spinal Muscular Atrophy (SMA) and autism.  The neuromuscular junction (NMJ) is a type of synapse between a motor neuron and muscles.  MicroRNAs are post-transcriptional repressors of gene expression that are potential regulators of the growth and development of the NMJ. Drosophila NMJ is used as model system because it has a conserved morphology and stereotyped connections.  This project is focused on beginning to identify microRNAs that play an important role in NMJ growth and development. 

MicroRNA sponge (miR-SP) technology is used to carry out the screening.  MiR-SP technology involves the expression of specific microRNA constructs using different drivers to decrease microRNA in a spatial and temporal manner.  We use the ubiquitous driver tubulin-Gal4 to decrease microRNA both pre- and post-synaptically. Immunoflourecence is used to visualize the morphology of the synaptic region and quantitative measurements of bouton number, branch number and synaptic area are collected on the NMJ of muscle 6/7. In this study we show MiR-8, a known regulator of synaptic development, is necessary for synaptic growth and morphology validating our methods for functional analysis of MiRs at the NMJ.