RRC ID 40040
Author Zeller J, Schneider V, Malayaman S, Higashijima S, Okamoto H, Gui J, Lin S, Granato M.
Title Migration of zebrafish spinal motor nerves into the periphery requires multiple myotome-derived cues.
Journal Dev. Biol.
Abstract In vertebrate embryos, spinal motor neurons project through segmentally reiterated nerves into the somites. Here, we report that zebrafish secondary motor neurons, which are similar to motor neurons in birds and mammals, depend on myotomal cues to navigate into the periphery. We show that the absence of myotomal adaxial cells in you-too/gli2 embryos severely impairs secondary motor axonal pathfinding, including their ability to project into the somites. Moreover, in diwanka mutant embryos, in which adaxial cells are present but fail to produce cues essential for primary motor growth cones to pioneer into the somites, secondary motor axons display similar pathfinding defects. The similarities between the axonal defects in you-too/gli2 and diwanka mutant embryos strongly suggest that pathfinding of secondary motor axons depends on myotome-derived cues, and that the diwanka gene is a likely candidate to produce or encode such a cue. Our experiments also demonstrate that diwanka plays a central role in the migration of primary and secondary motor neurons, suggesting that both neural populations share mechanisms underlying axonal pathfinding. In summary, we provide compelling evidence that myotomal cells produce multiple signals to initiate and control the migration of spinal nerve axons into the somites.
Volume 252(2)
Pages 241-56
Published 2002-12-15
PII S0012160602908523
PMID 12482713
MeSH Animals Cell Movement* In Situ Hybridization Motor Neurons / cytology* Somites Spine / embryology Spine / innervation* Zebrafish / embryology*
IF 3.262
Times Cited 58
Zebrafish rw0 (Tg(CM-isl1:GFP))