FIGURE 9.

Higher number of oligodendrocyte lineage cells in prenatal PTPα^−/− mouse brain and delayed maturation of oligodendrocytes in postnatal PTPα^−/− mouse brain. A, embryonic day 16 (E16) PTPα^−/− mouse embryos have more oligodendrocyte lineage cells in the forebrain compared with E16 WT mouse embryos. Brain sagittal sections of E16 mouse embryos were immunostained with antibodies against Olig2. The numbers of Olig2-positive cells in the thalamus region were counted. Scale bar, 85 μm. B, postnatal day 10 (P10) PTPα^−/− mice have fewer mature oligodendrocytes in the corpus callosum compared with P10 WT mice. Brain coronal sections of P10 and postnatal day 18 (P18) mice were immunostained with antibodies against NG2 and adenomatous poliposis coli (APC, clone CC1). The numbers of NG2-positive and CC1-positive cells in the central region of the corpus callosum (about 0.03 mm²) were counted. Scale bar, 30 μm. A and B, two sections/animal were counted. The values indicate mean ± S.D. cell counts obtained from two sections from three mice of each genotype per time point. C, P10 PTPα^−/− mice have less O4 immunoreactivity in corpus callosum compared with P10 WT mice. Brain coronal sections of P10 mice were immunostained with antibodies against NG2 and oligodendrocyte marker O4. Scale bar, 30 μm.