Molecular control of neuronal shape and connectivity in the developing retina

Morphology is a key determinant of neuronal circuit function, influencing how and where signals are received and transmitted. Although decades of work have established detailed models for how axons are specified and guided to their targets, much less is known about dendrite development. We discovered that the atypical cadherin Fat3 is a key regulator of neuronal morphology. In this project, we aim to define how Fat3 sculpts the neuronal cytoskeleton in response to signals in the surrounding environment. To tackle this question, we are focusing on retinal amacrine cells, which elaborate a single dendritic arbor and no axon. We will investigate the earliest stages of dendrite specification by imaging individually labeled amacrine cells as they develop in an ex vivo retinal explant, examining both interactions with other processes and how actin, microtubules, and the Golgi apparatus are re-arranged in response to these interactions. Imaging studies will be paired with a molecular dissection of Fat3, examining both possible extracellular ligands and intracellular effectors.