Fig. 5

Radial glia are required to restrict ectopic peripheral glial migration into the spinal cord. A: Images from a 24-h time-lapse of a Tg(sox10:eos) embryo treated at 24 hpf with MTZ and imaged from 48 to 72 hpf. Arrow denotes peripheral sox10⁺ cell that migrated into the spinal cord. Red dashed line denotes the edge of the spinal cord. Yellow dashed line denotes ectopically migrating PNS cell. B: Images from a 24-h time-lapse of a Tg(sox10:eos) embryo treated at 48 hpf with MTZ and imaged from 72 to 96 hpf. Arrow denotes peripheral sox10⁺ cell that migrated into the spinal cord. Red dashed line denotes the edge of the spinal cord. Yellow dashed line denotes ectopically migrating PNS cell. C: Schematic of the use of Eos photoconversion to demonstrate that peripheral sox10⁺ cells enter the spinal cord. PNS located glia at 48 hpf were photoconverted. D: In the experiment outlined in C, unconverted (green) and converted (red) Eos is shown in DMSO and MTZ-treated animals. Only in MTZ-treated animals are converted (red cells with asterisk) ectopically observed within the spinal cord. Arrowheads denote converted cells in controls that did not enter the spinal cord. Arrows denote radial glia endfeet in DMSO-treated animals and radial glia debris in MTZ-treated animals. Note that the ectopic cell in MTZ-treated animals also express unconverted Eos, distinguishing it from mcherry⁺ debris. E: Quantification of data from A and B showing the number of times a nerve had a cell ectopically migrate into the spinal cord (n = 6). Scale bars, 25 µm.