Fig. 1. Precocious astroglial differentiation in Dnmt1^–/– CNS in vivo. (A,B) Immunohistochemistry studies indicate enhanced S100ß- and GFAP-positive staining in E15.5 (A) and E18.5 (B) cervical spinal cords from littermate control (con) and Dnmt1^–/–mutant (mut) mice. Bottom rows show enlargements of the boxed areas in the tops rows. (C,D) Western blot analysis of GFAP (C) and S100ß (D) proteins in E12-18 spinal cords at cervical/thoracic level. (E) GFAP immunostaining (red, arrows) of the E18.5 cortical VZ/SVZ in coronal sections (relatively caudal regions) (LV, lateral ventricle; D/M, dorsal/medial; V/L, ventral/lateral). (F) GFAP immunostaining of E15.5 hippocampal primordial areas. Scale bar: 157 µm. (G) Western blot analysis of GFAP protein in E18.5 brain samples. CTX, cortex; CB, cerebellum; TH, thalamus; STR, striatum; OB, olfactory bulb. Reblotting with an antibody against ßIII-tubulin serves as an internal control for loading. (H) Northern analysis of GFAP mRNA in E18.5 whole brain samples. con, control; mut, Dnmt1^–/–.