Figure 3
Excessive apoptotic neuroblasts and reduction of cells in the granule cell lineage in the draxin KO SGZ. (A) Immunostaining of the P21 DG for active caspase-3. Arrowheads indicate apoptotic cells. (B) Quantification of immunoreactive cells in (A) Apoptotic cells were remarkably increased in KO mice (n = 6). (C) Confocal images of SGZ cells double-labeled for active caspase-3 and granule cell lineage markers. Over 150 active caspase-3-immunoreactive cells per mouse were counted for each marker (n = 4). Note that NeuroD1-expressing neuroblasts, but not nestin-expressing neural stem/progenitor cells or NeuN-expressing mature neurons, underwent excessive apoptosis in the KO SGZ. Number of apoptotic cells tends to increase in late progenitors expressing Tbr2 in draxin KO mice, but it was not significant from that in WT mice. (D–K) Confocal images of DG sections of P21 WT (D–G) and KO (H–K) mice immunostained with markers for neural stem cells (GFAP and Sox2; D and H), neural stem/early progenitor cells (nestin and Sox2; E and I), late progenitor cells (Tbr2; F and J), and neuroblasts (NeuroD1; G and K). Immunoreactive cells were quantified in L–O, respectively. Draxin deficiency drastically decreased the number of progenitors and neuroblasts (n = 4). Error bars indicate s.e.m. *p < 0.03, **p < 0.01 (Student’s t-test). Scale bars: 100 µm.
