Figure 1. Expression of GFAP promoter-driven Cre recombinase deletes astrocytic YY1 in the brain.

(A) Genomic DNA from mouse tail snips were processed for genotyping by PCR, followed by agarose gel electrophoresis. GFAP^cre/− and YY1-floxed (YY1^flox/flox) mice show mutant DNA bands that are positive for inserting Cre recombinase and loxP sequences, respectively. YY1 cKO mice are positive for both GFAP^cre/− and YY1-floxed sequences. (B-C) Brain tissue samples from YY1-floxed only (WT) and YY1 cKO (cKO) mice were assessed for the expression of Cre recombinase (B) and YY1 (C) by western blotting. (C) Immunoblotting image and quantification of relative YY1 protein levels were assessed in the cortex (Ctx), midbrain (MB), and cerebellum (CB). β-actin was used as a loading control for proteins. (D-F) Expression of YY1, Iba, GFAP, and NeuN in the cortex (D), midbrain (E), and cerebellum (F) of WT and YY1 cKO mice (×40 magnification with a confocal microscope, scale represent 50 μm). Insets show a higher magnification of a region from the imaging. Yellow arrowheads depict YY1 (blue) in astrocytes (GFAP, green), as well as in microglia (Iba1, magenta) and neurons (NeuN, red) of WT cortex, midbrain, and cerebellum, whereas white arrowheads indicate no YY1 expression in astrocytes of YY1 cKO mice.