Figure 2
Stereotyped Axon Formation Follows Basal Protrusion Retraction (A) Image sequence from a time lapse showing a neuron with long basal protrusions (white arrows) that are fully retracted before axon initiation (blue arrow at time 3h09). The axon grows circumferentially and crosses the ventral floor plate (blue arrow at time 4h05) ( (B) Image sequence from a time lapse shows a neuron with long basal protrusions (white arrows) that are fully retracted before axon initiation (blue arrow at time 8h11). The axon is initiated from the ventral surface of the neuron and then grows longitudinally and ipsilaterally along the spinal cord (blue arrow at time 11h29). (C) Image sequence from a time lapse of a motor neuron with short basal protrusions (white arrows) that are retracted by time point 0h35. The exact point of axon extension is not clear, but the axon (blue arrow) changes direction to leave ventral spinal cord and grow into muscle at time 3h30. (D) Summary diagram of neuron morphologies shown in (A)–(C). Neurons were labeled with membrane-GFP (green) and H2B-RFP to show nuclei in A and C. All images are projected images from confocal z stacks. |
Reprinted from Developmental Cell, 49, Hadjivasiliou, Z., Moore, R.E., McIntosh, R., Galea, G.L., Clarke, J.D.W., Alexandre, P., Basal Protrusions Mediate Spatiotemporal Patterns of Spinal Neuron Differentiation, 907-919.e10, Copyright (2019) with permission from Elsevier. Full text @ Dev. Cell