Figure 6.

DINE deficiency causes morphological alterations in immature Schwann cells along the phrenic nerve. A, Semithin sections of the sagittal diaphragm at E17.5 of WT and KO mice stained with toluidine blue (top) and higher magnification of toluidine blue-stained sections of diaphragm (bottom). Dashed line indicates border between phrenic nerve and muscle. Phrenic nerve of WT mouse has spindle-shaped cells (white arrowheads), whereas the cells in the KO mouse are rounded (black arrowheads). B, Sagittal sections of paraffin-embedded diaphragm at E17.5 from WT and KO mice immunostained with anti-p75 (green) and anti-neurofilament (NF, red) antibodies and DAPI (blue). Bottom three rows represent higher magnification of white frame in the top. Most DAPI-stained nuclei possibly indicate p75-positive immature Schwann cells. The shapes of DAPI-stained nuclei are flat in the WT mouse (white arrowheads) but rounded in the KO mouse (open arrowheads). Dashed line indicates outline of phrenic nerve. Scale bars: A, B, 20 μm.