Fig. 5. Dystroglycan siRNA causes a decrease in oligodendrocyte differentiation and myelin protein production. (A) Dystroglycan expression is reduced in oligodendrocytes differentiated following transfection with siRNA designed to target dystroglycan mRNA (DG siRNA) compared with control siRNA (ctrl siRNA). Representative fields of cells visualized with -dystroglycan antibodies (anti-DG) are shown. (B) Immunoblots using lysates obtained from cells transfected with control (ctrl) or dystroglycan (DG) siRNA following 2 or 4 days differentiation. Blots were probed with antibodies to detect -dystroglycan, ß-dystroglycan, MBP (late-stage oligodendrocyte marker; MBP' shows a longer exposure to visualize the MBP at day 2), CNP (2',3'-cyclic nucleotide 3'-phosphodiesterase, mid-stage oligodendrocyte marker), NG2 (early stage oligodendrocyte marker) or actin (loading control). (C,D) Average expression, relative to control siRNA at 100%, for MBP or CNP at day 2 (C; n=3; ^*P<0.05 and ^**P<0.01) or day 4 (D; n=4; ^**P<0.01) (error bars represent s.d.). Black bars depict control siRNA and gray bars depict dystroglycan siRNA. (E) Average percentage of cells, treated with either control (ctrl) or dystroglycan siRNA, that express MBP, as determined by immunocytochemistry (n=4, error bars represent s.d.). (F) Representative fields of MBP immunocytochemistry as described in E.