Frizzled/RYK mediated signalling in axon guidance

Successful axon navigation depends on the competence of the axon growing tip to receive and integrate information provided by multiple, spatially organised molecular cues arranged along the axon trajectory. Several recent studies have raised the intriguing possibility that 'morphogen' signalling, known to give cell-specific positional information during tissue patterning, is later used to provide part of this guidance information to the growth cone. How general this strategy is has now become apparent with new compelling evidence from the Wnt field, which shows that new ligand-receptor interactions underlie the evolutionary conserved role of the Wnt signalling cascade in the initiation, elongation and turning behaviour of the growth cone.