Regulation of Drosophila Neural Circuit Assembly by Cell Surface Molecules

Abstract

Nervous systems assemble with remarkable organization and precision. Developmental mechanisms ensure that neurons identify and form specific synapses with the correct set of neurons at the appropriate subcellular locations. This precise connectivity determines how information flows within circuits and defines key aspects of neural circuit function. Understanding the molecular mechanisms that underlie synapse specificity has the potential to provide insight into neurodevelopmental disorders and their etiology, and to inform the development of treatments. Cell surface molecules (CSMs) are well positioned to regulate synaptic partner choice and have emerged as key regulators of axon guidance, cell recognition, and synapse formation. To better understand synapse specificity, it is critical to characterize CSM function and their roles in neural development. Here, I describe a model system designed to identify CSMs, or other classes of genes, that regulate synapse specificity in pairs of larval Drosophila neurons. Using this model system, I investigated the role of Dpr/DIP genes, cell adhesion molecules in the immunoglobulin family, in synapse formation. Furthermore, I explored the role of axon guidance molecules, Robo-2 and Unc-5, in the subcellular positioning of synapses in these neurons, and explored the contribution of dendritogenesis in the regulation of synapse specificity. This dissertation contains previously published co-authored material (Chapter 4).