(A) Average G/R ratios of each cell type in brain parenchyma of P60 mutant-MADM mice. * P<0.05, ** P<0.01, paired T-test. “#” P<0.0001, one-way ANOVA.
(B) Left chart: with a single BrdU injection (1.5 hours prior to sacrifice) at P60, BrdU-positive mutant (−/−) cells in the brain parenchyma consist entirely of OPCs (PDGFRα+). Right chart: upon BrdU administration by drinking water for one week, all BrdU-positive mutant (−/−) cells in the brain parenchyma belong to the oligodendrocytic lineage (Olig2+), and the majority of them are OPCs (PDGFRα+).
(C–E) “4+1” channel staining shows that all BrdU+ mutant OPCs in a P60 mutant-MADM mouse brain belong to the oligodendrocyte lineage. (C) Without Olig2 staining, all MADM labeled BrdU+ cells are mutant (green). Notably, some BrdU+ mutant cells are PDGFRα negative (marked with cyan circles).
(D) An adjacent section stained with Olig2 together with MADM, BrdU, and PDGFRα, shows that all mutant BrdU+ cells have red nuclei, indicating positive staining of Olig2. (E) Representative magnified confocal images show: mutant cells without Olig2 staining (left), mutant cells with Olig2 staining in red channel (middle), and heterozygous yellow cells (right). The orthogonal Z-axis is shown on the side of each panel. Scale bars: (C and D): 20μm, insets, 5 μm; (E): 5μm.
(F) G/R ratios of BrdU+ cells in the SVZ and NeuN+ cells in the olfactory bulb (OB) from P60 mutant-MADM mice. BrdU was given in drinking water for 7 days.
(G) Quantification of cells with indicated genotypes among all BrdU+ cells in the non-SVZ brain parenchyma (left chart) or the SVZ (right chart) after one week of BrdU administration. N=3 mice for all quantification in (A, B, F and G). See and Extended experimental procedures for detailed systematic sampling schemes. Error bars represent +/− SEM. Total cell numbers counted in (A, B, F and G) are shown in parenthesis. Each number is the sum from 3 brains.
See also .