Expression of SR proteins in MDM. A: Western blot detection of ASF/SF2 and SC35 in nuclear extracts from uninfected and HIV-infected MDM over a 4–5 week period following infection. Representative of 6 cultures. B: Densitometric analysis as in Fig. 3 of Western blot expression of SC35 and ASF/SF2 in 3 representative infected MDM cultures (Donors A-C; black, grey and white bars respectively) relative to uninfected cells (Exp [I] : Exp [UI]) at each time point. Mean expression levels are shown in the top right hand panel (mean + SEM of 6 cultures). Relative SC35 expression, normalized to levels at 1 week post-infection, is shown in the bottom right hand panel. C: Confocal scanning laser microscopy of SC35 expression in the nuclei of uninfected and infected MDM 2 and 5 weeks after infection of a separate donor culture from those used in A and B above. Specific nuclear fluorescence (Fn-b) for infected and uninfected cells (bottom left hand panel) and relative nuclear fluorescence (Fn-b [I] : Fn-b [UI], bottom right hand panel) over that period, as per Fig. 3, are shown. Top right hand panel shows the ratio of nuclear to cytoplasmic fluorescence (Fn/c) of infected cells relative to uninfected cells (Fn/c [I] : Fn/c [UI]) for weeks 2 and 5. Fn/c > 1 indicates predominantly nuclear localisation, while Fn/c < 1 represents predominantly cellular localisation. Representative of 6 donors.