(A) Schematic diagram of the Cre-IRES-LacZ transgene that was inserted at the first coding ATG of the Gad1 gene on BAC RPCI23-118N13. The Neo cassette was removed by Flp-mediated recombination at the frt sites after selection. (B) Gad1-Cre-mediated recombination visualized using anti-EG(Y)FP antibody in a 4.5 month-old Gad1-Cre, Rosa26yfp/yfp mouse. Upper panels: Representative images of a sagittal (left), and a coronal section (right). Lower panels: magnification of the areas indicated with solid and dotted lines in the upper left panel. Lower left panel: layers I–VI of somatosensory cortex. Lower right panel: anterior part of the hippocampus. bs, brainstem; cb, cerebellum; co, colliculi; cx, neocortex; dg, dentate gyrus; hi, hippocampus; hy, hypothalamus; st, striatum; th, thalamus; bactP, bacterial promoter; frt, Flp recombinase target site; H, hybrid intron; HA, homologous arm; IRES, internal ribosomal entry site; LacZ, beta-galactosidase encoding gene; Neo, neomycin resistance gene; PA, polyadenylation signal; SVe, SV40 enhancer.