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dc.contributor.advisor Stern, Michael J
dc.creatorSummerville, James Brian
dc.date.accessioned 2017-08-02T16:19:34Z
dc.date.available 2017-08-02T16:19:34Z
dc.date.created 2016-05
dc.date.issued 2016-04-21
dc.date.submitted May 2016
dc.identifier.citation Summerville, James Brian. "The Effects of ER Morphology on Synaptic Structure and Function in Drosophila melanogaster." (2016) Diss., Rice University. https://hdl.handle.net/1911/96186.
dc.identifier.urihttps://hdl.handle.net/1911/96186
dc.description.abstract Hereditary Spastic Paraplegias (HSPs) comprise a diverse set of genetic diseases caused by mutations in any of up to 70 genes, named SPG1 to SPG72. Age-dependent corticospinal axon degeneration, accompanied by spasticity and weakening of the lower limbs, represents the most prominent HSP clinical feature. Two genes implicated in HSPs encode proteins that regulate ER morphology. Atlastin (responsible for SPG3A), encodes an ER membrane GTPase responsible for the fusion of juxtaposed ER membranes, and Reticulon 2 (responsible for SPG12), inserts into the ER membrane, induces membrane curvature, and thus promotes ER tube formation. Here we describe the effects of altered atlastin (atl) and reticulon (Rtnl1) on ER structure, evoked neurotransmitter release, synaptic bouton formation (arborization), and locomotor behavior in Drosophila. Using a novel fluorescent ER marker, we show that the ER within wildtype motor nerve terminals forms an elaborate network of tubules that resembles a “basket”, but this network is fragmented and diffuse in larvae lacking atl. Additionally, we find that loss of atl or Rtnl1 decreases evoked transmitter release from motor neurons and increases motor neuron arborization. We also find that atl acts cell autonomously in the motor neuron to affect transmitter release, whereas Rtnl1 acts in all three cell types (neuron, muscle, and peripheral glia) of the tripartite synapse to control transmitter release. Similarly to other HSP genes, atl inhibits bone morphogenetic protein (BMP) signaling, and loss of atl causes age-dependent locomotor deficits in adults. These results demonstrate a critical role for the ER in neuronal function and identify mechanistic links between ER morphology, neuronal structure and function, BMP signaling, and adult behavior. These studies provide novel insights into the mechanisms underlying the neurological deficits in these HSPs.
dc.format.mimetype application/pdf
dc.language.iso eng
dc.subjectendoplasmic reticulum
atlastin
reticulon
ER morphology
synaptic transmission
Drosophila melanogaster
dc.title The Effects of ER Morphology on Synaptic Structure and Function in Drosophila melanogaster
dc.date.updated 2017-08-02T16:19:34Z
dc.type.genre Thesis
dc.type.material Text
thesis.degree.department Biochemistry and Cell Biology
thesis.degree.discipline Natural Sciences
thesis.degree.grantor Rice University
thesis.degree.level Doctoral
thesis.degree.name Doctor of Philosophy


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