RRC ID 33662
Author Wanner SJ, Prince VE.
Title Axon tracts guide zebrafish facial branchiomotor neuron migration through the hindbrain.
Journal Development
Abstract Appropriate localization of neurons within the brain is a crucial component of the establishment of neural circuitry. In the zebrafish hindbrain, the facial branchiomotor neurons (FBMNs) undergo a chain-like tangential migration from their birthplace in rhombomere (r) 4 to their final destination in r6/r7. Here, we report that ablation of either the cell body or the trailing axon of the leading FBMN, or 'pioneer' neuron, blocks the migration of follower FBMNs into r5. This demonstrates that the pioneer neuron and its axon are crucial to the early migration of FBMNs. Later migration from r5 to r6 is not dependent on pioneer neurons but on the medial longitudinal fasciculus (MLF), a bundle of axons lying ventral to the FBMNs. We find that MLF axons enter r5 only after the pioneer neuron has led several followers into this region; the MLF is then contacted by projections from the FBMNs. The interactions between FBMNs and the MLF are important for migration from r5 to r6, as blocking MLF axons from entering the hindbrain can stall FBMN migration in r5. Finally, we have found that the adhesion molecule Cdh2 (N-cadherin) is important for interactions between the MLF and FBMNs, as well as for interactions between the trailing axon of the pioneer neuron and follower FBMNs. Interestingly, migration of pioneer neurons is independent of both the MLF and Cdh2, suggesting pioneer migration relies on independent cues.
Volume 140(4)
Pages 906-15
Published 2013-2
DOI 10.1242/dev.087148
PII dev.087148
PMID 23325758
PMC PMC3557781
MeSH Animals Axons / physiology* Cell Movement / physiology* Facial Nerve / cytology* Immunohistochemistry Microscopy, Confocal Models, Neurological Morpholinos / genetics Motor Neurons / physiology* Rhombencephalon / embryology* Zebrafish / embryology*
IF 5.763
Times Cited 13
Zebrafish Tg(isl1:GFP)/rw0