Fig. 1
Myrf ICKO mice have effective recombination in OPCs following moderate thoracic SCI. a Illustration of transgenes used in this experiment. Myrf ICKO mice were generated by crossing mice with exon 8 of Myrf floxed with mice with the PDGFRα-CreERT2 transgene to produce Myrffl/fl PDGFRα-CreERT2 mice. Control mice lacked the PDGFRα-CreERT2 transgene. b Illustration of experimental timeline. c Impact force (kilodynes) imparted on the spinal cord during SCI indicates no difference between groups (df = 25, t = 0.103, P = 0.912, Student’s t test). d Displacement (µm) of the impactor tip upon contact with the spinal cord during thoracic contusion shows no statistical difference between groups (df = 25, t = 0.037, P = 0.971, Student’s t test). e Overview images from the ventrolateral white matter adjacent to the lesion epicenter in control and Myrf ICKO mice crossed with a tamoxifen inducible reporter that tethers GFP to the membrane (mT/mG). The majority of PDGFRα + OLIG2 + cells are recombined (GFP expression, yellow arrows), but occasional nonrecombined PDGFRα + cells are observed (PDGFRα + GFP−, blue arrows). f Inlays of single optical sections demonstrating colabeling of PDGFRα with GFP in OLIG2 + cells. g Quantification of the recombination efficiency in OPCs at six WPI. There is no difference in recombination between control and Myrf ICKO mice (df = 10, t = 0.368, P = 0.627, Student’s t test). h Single optical confocal section micrographs demonstrating colabeling of MYRF in CC1 + OLIG2 + oligodendrocytes (yellow arrows). OLIG2 + cells lacking CC1 do not have MYRF expression in either group (blue arrows). i Single optical section from control or Myrf ICKO mice demonstrating colabeling of MYRF in CC1 + EdU + oligodendrocytes (blue arrows) in control mice, but not in CC1 + EdU + oligodendrocytes in Myrf ICKO mice (white arrows). j Spinal cord cross-section of the lesion epicenter stained for GFAP at six weeks post injury (WPI) in Myrf ICKO and control mice. k Quantification of GFAP + spared tissue at different distances from lesion epicenter. There is no significant difference between Myrf ICKO and control mice at any given distance from lesion epicenter (multiple Student’s t test with Holm-Šídák correction, epicenter t = 1.095, P = 0.291) ns non-significant. Scalebars = 50 µm (e), 10 µm (h), 5 µm (i), 100 µm (j) . Error bars are mean ± SEM
