| Title | Muscle contractions guide rohon-beard peripheral sensory axons. | | Author(s) | Paulus JD, Willer GB, Willer JR, Gregg RG, Halloran MC | | Institution | Departments of Zoology and Anatomy and Cell and Molecular Biology Training Program, University of Wisconsin, Madison, Wisconsin 53706, USA. | | Source | J Neurosci 2009 Oct 21; 29(42):13190-201. | | MeSH | Animals
Animals, Genetically Modified
Axons
Body Patterning
Chondroitin ABC Lyase
Embryo, Nonmammalian
Gene Expression Regulation, Developmental
Green Fluorescent Proteins
Hedgehog Proteins
Muscle Contraction
Muscle Proteins
Muscle, Skeletal
Mutation
Neuromuscular Nondepolarizing Agents
Peripheral Nerves
Protein Kinases
Sensory Receptor Cells
Signal Transduction
Time Factors
Tubocurarine
Zebrafish
Zebrafish Proteins
| | Abstract | Multiple molecular cues guide neuronal axons to their targets during development. Previous studies in vitro have shown that mechanical stimulation also can affect axon growth; however, whether mechanical force contributes to axon guidance in vivo is unknown. We investigated the role of muscle contractions in the guidance of zebrafish peripheral Rohon-Beard (RB) sensory axons in vivo. We analyzed several mutants that affect muscle contraction through different molecular pathways, including a new mutant allele of the titin a (pik) gene, mutants that affect the hedgehog signaling pathway, and a nicotinic acetylcholine receptor mutant. We found RB axon defects in these mutants, the severity of which appeared to correlate with the extent of muscle contraction loss. These axons extend between the muscle and skin and normally have ventral trajectories and repel each other on contact. RB peripheral axons in muscle mutants extend longitudinally instead of ventrally, and the axons fail to repel one another on contact. In addition, we showed that limiting muscle movements by embedding embryos in agarose caused similar defects in peripheral RB axon guidance. This work suggests that the mechanical forces generated by muscle contractions are necessary for proper sensory axon pathfinding in vivo. | | Language | eng | | Pub Type(s) | Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
| | PubMed ID | 19846707 |
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