Loss of p27 does not alter nerve development. (A) Semithin sections of sciatic nerve from P60 WT and p27^−/− mice and fiber type distribution per axon diameter. Bar, 20 µm. (B) Quantification of Schwann cell number and percentage of BrdU-, Ki67-, and double BrdU/Ki67-positive staining in nerves of P5 WT and p27^−/− mice (n = 3 mice per genotype per experiment). (C) Western blots for Oct6 and Krox20 in sciatic nerve homogenate of P5 WT and p27^−/− mice. Calnexin was used as a loading control. Quantification is reported as the mean of three independent mice per genotype and represented as ratio Oct6 or Krox20/calnexin, assigning WT as 1. (D) Internodal length of P30 WT and p27^−/− sciatic nerve (n = 100 fibers per mouse, three mice per genotype). Paired Student’s t test: **, P ≤ 0.01. Error bars indicate SEM.