Neurexin Restricts Axonal Branching in Columns by Promoting Ephrin Clustering

Publication date: Available online 30 March 2017
Source:Developmental Cell
Author(s): Lina Liu, Yao Tian, Xiao-yan Zhang, Xinwang Zhang, Tao Li, Wei Xie, Junhai Han
Columnar restriction of neurites is critical for forming nonoverlapping receptive fields and preserving spatial sensory information from the periphery in both vertebrate and invertebrate nervous systems, but the underlying molecular mechanisms remain largely unknown. Here, we demonstrate that Drosophila homolog of α-neurexin (DNrx) plays an essential role in columnar restriction during L4 axon branching. Depletion of DNrx from L4 neurons resulted in misprojection of L4 axonal branches into neighboring columns due to impaired ephrin clustering. The proper ephrin clustering requires its interaction with the intracellular region of DNrx. Furthermore, we find that Drosophila neuroligin 4 (DNlg4) in Tm2 neurons binds to DNrx and initiates DNrx clustering in L4 neurons, which subsequently induces ephrin clustering. Our study demonstrates that DNrx promotes ephrin clustering and reveals that ephrin/Eph signaling from adjacent L4 neurons restricts axonal branches of L4 neurons in columns.

Graphical abstract

Teaser

Columnar restriction of neurites is commonly observed in the nervous system. Liu, Tian et al. demonstrate that α-neurexin promotes ephrin clustering via its intercellular domain and that ephrin/Eph signaling from adjacent L4 neurons restricts L4 axon branches into columns.


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