# Neuron-secreted chemokine-like Orion interacts with the glial receptor Draper during mushroom body neuronal remodeling in Drosophila

## TL;DR

The study shows that the chemokine-like protein Orion interacts with the Draper receptor in glial cells to regulate neuronal remodeling in fruit fly brains.

## Contribution

The study identifies Drpr as the glial receptor for Orion during mushroom body neuronal remodeling in Drosophila.

## Key findings

- A drpr null allele shows a pruning phenotype similar to orion null alleles.
- Tethering Orion to γ-axons causes strong genetic interactions with Drpr.
- Drpr is likely the glial receptor for Orion in neuronal remodeling.

## Abstract

Across the animal kingdom, neuronal remodeling is a crucial developmental mechanism to refine neurite targeting necessary for both maturation and function of neural circuits. The neuronal chemokine-like Orion is essential for astrocyte infiltration and likely for phagocytosis during mushroom body γ-neuron remodeling during metamorphosis in Drosophila. The Drpr phagocytic receptor is a critical and well-studied regulator of many aspects of neuronal remodeling, where it is required for neurite pruning and cell body removal. In this study, we show a drpr

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allele displaying a mushroom body (MB)-pruning phenotype very similar, if not identical, to that of orion

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alleles. Furthermore, when Orion is permanently tethered to the surface of the γ-axons, we show strong genetic interactions between neuronal Orion and glial Drpr. These results strongly suggest that Drpr is the glial receptor for Orion in mushroom body neuronal remodeling.