Coordinated motor neuron axon growth and neuromuscular synaptogenesis are promoted by CPG15 in vivo.
We have used in vivo time-lapse two-photon imaging of single motor neuron axons labeled with GFP combined with labeling of presynaptic vesicle clusters and postsynaptic acetylcholine receptors in Xenopus laevis tadpoles to determine the dynamic rearrangement of individual axon branches and synaptogenesis during motor axon arbor development. Control GFP-labeled axons are highly dynamic during the period when axon arbors are elaborating. Axon branches emerge from sites of synaptic vesicle clusters. These data indicate that motor neuron axon elaboration and synaptogenesis are concurrent and iterative. We tested the role of Candidate Plasticity Gene 15 (CPG15, also known as Neuritin), an activity-regulated gene that is expressed in the developing motor neurons in this process. CPG15 expression enhances the development of motor neuron axon arbors by promoting neuromuscular synaptogenesis and by increasing the addition of new axon branches.
Javaherian
Ashkan
A
Graduate Program in Genetics, Stony Brook University, Stony Brook, New York 11790, USA.
Cline
Hollis T
HT
D000818:Animals; D001369:Axons / Q000502:physiology*; D001426:Bacterial Proteins / Q000378:metabolism; D002038:Bungarotoxins / Q000378:metabolism; D003952:Diagnostic Imaging / Q000379:methods; D018274:Electroporation / Q000379:methods; D015870:Gene Expression / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000502:physiology*; D009046:Motor Neurons / Q000166:cytology*; D009419:Nerve Tissue Proteins / Q000502:physiology*; D009469:Neuromuscular Junction / Q000196:embryology* / Q000502:physiology; D038081:Organogenesis; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D013572:Synaptic Vesicles / Q000378:metabolism; D016708:Synaptophysin / Q000378:metabolism; D014982:Xenopus laevis / Q000196:embryology
D001426:Bacterial Proteins; D002038:Bungarotoxins; D008164:Luminescent Proteins; D008565:Membrane Proteins; C484390:NRN1 protein, Xenopus; D009419:Nerve Tissue Proteins; D016708:Synaptophysin; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins; D010751:Phosphopyruvate Hydratase