Figure 2.

Characterization of the conditional Dab1 transgenic mouse. A, Western blot of Dab1 expression in adult WT (Dab1^+/+), homozygous floxed Dab1 (Dab1^flox/flox), heterozygous floxed Dab1 (Dab1^flox/+), homozygous Dab1 crossed with a conditional ubiquitous Cre-line injected with tamoxifen (UbiCreER^T2/Dab1^flox/flox+TMX), and heterozygous Dab1 crossed with a conditional ubiquitous Cre-line (UbiCreER^T2/Dab1^flox/+). B, Scheme of the conditional Dab1 knockout triple-transgenic generation. Administration of TMX induces the removal of the dab1 expression cassette by Cre-mediated recombination and consequent expression of the β-galactosidase reporter. At the same time, the drug induces the expression of YFP in Nestin-expressing cells. C, D, Expression of the β-galactosidase reporter in adult-generated neurons in the DG after tamoxifen injection in adult NestinCreER^T2/Dab1^flox/flox mice. E–H, Expression of YFP in postnatally generated cells 7 weeks after injection of tamoxifen at P7–P8 or P28–P32 in NestinCreER^T2/R26YFP/Dab1^+/+ or NestinCreER^T2/R26YFP/Dab1^flox/flox mice. Arrows, Ectopically located cells; arrowhead, labeled glia in the hilus. I, Quantification of hilar ectopic DGCs showed increases in Nestin-CreER^T2/Dab1^flox/flox mice treated with TMX at P7–P8 (*p < 0.01) or P28–P32 (*p < 0.001), and in Nestin-CreERT2/Dab1^flox/+ given TMX at P7–P8 (*p = 0.001) versus TMX-treated Nestin-CreERT2/Dab1^+/+ controls (Con; early- and late-treated controls showed no difference and results were pooled). Scale bar: E–H (in E), 75 μm.