Fig. 4

Pals1a and aPKCλ are not required for radial sorting and myelination by Schwann cells. TEM of a cross section of the PLLn at 3 dpf in control (A and A′), has^−/− (B and B′), and nok^−/− (C and C′) embryos. Magenta asterisks represent some large caliber myelinated axons. SC, Schwann cell. Scale bars = 0.5 μm. (D) Quantification of the number of myelinated axons per nerve at 3 dpf in control (average of 5.6 ± 0.55, 9 nerves, n = 5 embryos), has^−/− (5.55 ± 0.53, 9 nerves, n = 5 embryos), and nok^−/− (average of 5.9 ± 0.4, 10 nerves, n = 5 embryos) embryos. (ns, P > .87 in all other cases). (E) Quantification of the total number of axons per nerve at 3 dpf in control (average of 55 ± 2.85), has^−/− (average of 43.67 ± 3.94), and nok^−/− (average of 53 ± 3.22) embryos. (ns, P > .07 in all cases). (F) Quantification of the percentage of myelinated axons relative to the total number of axons per nerve at 3 dpf in control (average of 10.46 ± 1.14%), has^−/− (average of 12.88 ± 0.73%), and nok^−/− (average of 11.34 ± 0.85%) embryos. (ns, P > .18 in all cases). (G) Quantification of the percentage of axons relative to their diameter at 3 dpf in control (average of 59.15 ± 4.31% for 0-0.4 μm; average of 40.84 ± 4.2% for >0.4 μm), has^−/− (average of 54.4 ± 5.99% for 0-0.4 μm; average of 45.59 ± 5.8% for >0.4 μm), and nok^−/− (average of 56.3 ± 4.1% for 0-0.4 μm; average of 43.7 ± 4.2% for >0.4 μm) embryos. (ns, P > .87 in all cases). (H) Graph representing the distribution of axons relative to their diameter with 0.1 μm bin width at 3 dpf in control, has^−/− and nok^−/− embryos (ns, P > .999 in all cases)