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Updated: May 5, 2026

Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster
Published on: March 4, 2013
A signaling network for patterning of neuronal connectivity in the Drosophila brain
Mohammed Srahna1, Maarten Leyssen, Ching Man Choi
1Laboratory of Neurogenetics, Department of Molecular and Developmental Genetics, Flanders Interuniversity Institute for Biotechnology (VIB), University of Leuven School of Medicine, Leuven, Belgium.
Abstract:
The precise number and pattern of axonal connections generated during brain development regulates animal behavior. Therefore, understanding how developmental signals interact to regulate axonal extension and retraction to achieve precise neuronal connectivity is a fundamental goal of neurobiology. We investigated this question in the developing adult brain of Drosophila and find that it is regulated by crosstalk between Wnt, fibroblast growth factor (FGF) receptor, and Jun N-terminal kinase (JNK) signaling, but independent of neuronal activity. The Rac1 GTPase integrates a Wnt-Frizzled-Disheveled axon-stabilizing signal and a Branchless (FGF)-Breathless (FGF receptor) axon-retracting signal to modulate JNK activity. JNK activity is necessary and sufficient for axon extension, whereas the antagonistic Wnt and FGF signals act to balance the extension and retraction required for the generation of the precise wiring pattern.

