Tissue-selective deletion of dystroglycan. a, Western blot analysis of brain. WT, wild type; DG-null, GFAP-Cre/DG-null; DG+/-, heterozygous dystroglycan null; DGlox/-, heterozygous floxed/dystroglycan-null; DGlox/lox, homozygous floxed. b, Western blot with a b-DG antibody. c, b-DG immunofluorescence of control cerebral cortex shows staining of smooth muscle in a small cerebral artery on the pial surface and astrocyte foot processes along the glia limitans and cerebral microvessels (arrow points to one microvessel). d,b -DG immunofluorescence is retained in only a small cerebral artery on the surface of DG-null cerebrum. e, Dystrophin immunofluorescence parallels that of b-DG in control brain. f, Dystrophin immunofluorescence is retained only in vessels of the meninges of DG-null brain. The position of the unstained glia limitans is marked by a dashed white line in d and f.