Axon guidance and bundling are linked

Netrin-1 bound to Draxin
Netrin-1 (blue/green), a molecule that guides axons towards the midline, works together with Draxin (pink), which drives axons to gather into bundles. IMAGE: Liu Y. et al. 2018


EMBL scientists discover how two guidance cues work together when neurons project axons across the midline

Rob Meijers’ lab at EMBL in Hamburg have found that axon guidance is more complicated than was thought. During spinal cord development, neurons have to project axons across the midline, to coordinate movements between the left and right sides of the body. Working with collaborators at Peking University (China), Meijers discovered how a molecule that guides axons towards the midline (Netrin-1) works together with another that drives axons to gather into bundles (Draxin). In a study published in Neuron, they determined the 3D structure of Draxin alone, bound to part of Netrin-1, and bound to the receptor that the axon uses to detect both guidance cues, and found that Netrin-1 and Draxin can link up to form a bridge between axons.

Meijers describes the paper in a video abstract for Neuron: