Elucidating the Role of RNA-binding Proteins in Drosophila Sensory Neuron Development

Abstract

Neurons are a diverse group of cells, with their unique morphology often linked to specific functional requirements. The intricate morphology of neurons necessitates a multilayered developmental process, with regulation occurring at the transcriptional, post-transcriptional and post-translational levels. RNA-binding proteins (RBPs) that mediate post-transcriptional regulation can function at all stages of the lifecycle of a transcript, allowing for rapid and localized control over gene expression. These regulatory features are particularly important in cells as expansive and morphologically complex as neurons. The Drosophila larval class IV dendritic arborization (da) neurons provide an ideal system for studying the role of RBPs in neuron development. These highly branched sensory neurons completely and non-redundantly tile the larval body wall. Here, we analyze the role of the RBP Found in neurons (Fne) in regulating the space-filling dendrite growth that is characteristic of these neurons. Our results indicate that Fne regulates multiple transcripts and in doing so, is able to modulate both processes intrinsic to the neuron as well as interactions between the neuron and the surrounding environment. By regulating multiple, functionally-related transcripts in tandem, Fne is able to act as a central coordinator of neuronal morphology. This synchronized regulation is likely to be an important feature of many other RBPs that have been implicated in neuronal morphogenesis. Furthermore, our results reveal that the molecular mechanisms underlying the role of Fne in class IV da neurons are distinct from its recently revealed functions in the central nervous system. The differences in Fne function in various types of neurons, and therefore its participation in distinct regulatory processes, could be a feature that is common to many RBPs and may contribute to the vast morphological diversity observed in neurons.