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Publication Date

Spring 2013

Degree Type

Thesis - Campus Access Only

Degree Name

Master of Science (MS)


Biological Sciences


Miri K. VanHoven

Subject Areas

Genetics; Neurosciences


Critical processes such as perception, movement, and thought rely on correct

communication between neurons. The nervous system is made up of neurons that communicate through synapses formed between dendrites and axons. Dendrites typically receive information from the environment or other neurons, while axons typically relay information to other neurons. It is thought that molecular stop signals instruct axons when to stop extending during development and may maintain this length after development. Identifying the molecular stop signals and their receptors may provide researchers with molecular targets for designing drug therapies to treat nervous system injuries. With a sequence genome as well as a simple and well-characterized nervous system, C. elegans is an ideal model organism in which to conduct such studies. We labeled PHB-class sensory neurons with a cytosolic mCherry fluorophore to assay axon length. Analysis of loss-of-function mutants indicated that the transmembrane receptor SAX-3/Roundabout (Robo), previously isolated for its role in directing axons and cell bodies away from certain regions of the body, is also required for correct termination of axon outgrowth. Our project aimed to investigate the role of SAX-3/Robo in axon outgrowth termination and to elucidate the pathway by which it transduces the termination signal.