Mouse strains

All transgenic animals used in this study were maintained on ICR/CD-1, FVB/N-Tg, or C57BL/6J genetic backgrounds and genotyped by PCR. The day of the vaginal plug was stipulated as E0.5. The Gfap::Gfp line (16) (the Jackson Laboratory, stock number 003257) was in an FVB/N-Tg genetic background, the Gad67::Gfp line (43) was in C57BL/6J, and the R26^tdTomato Cre-dependent line (the Jackson Laboratory, stock number 007908) and the Gbx2^CreERT2/+ mouse line (18) were in an ICR/CD-1 genetic background. Tamoxifen induction of Cre recombinase in the double-mutant embryos (Gbx2^CreERT2/+::R26^tdTomato) was performed as previously described (44). The Committee on Animal Research at the University Miguel Hernández approved all the animal procedures, which were carried out in compliance with Spanish and European Union regulations.