FIG. 7.

HP1βΔN blocks deposition of HP1 proteins in SAHF, but has no effect on chromosome condensation, deposition of macroH2A protein, or accumulation of H3K9Me in SAHF. (A) WI38 cells were infected with vector control (Cont or Con) or HP1βΔN-expressing virus, together with a virus containing an activated Ras oncogene, as indicated. The infected cells were selected with 3 μg/ml puromycin and 500 μg/ml G418. Eight days postinfection, the cells were stained with antibodies to HP1β and macroH2A1.2. (B) One hundred cells shown in panel A were scored for chromosome condensation (DAPI foci) and deposition of macroH2A1.2 and HP1β in SAHF (colocalization of macroH2A1.2 and HP1β, respectively, with DAPI). Cells with macroH2A foci do not include cells with a visible inactive X chromosome only. (C) As in panel A but stained with antibodies to H3K9Me2 and HP1β. (D) One hundred cells shown in panel C were scored for incorporation of H3K9Me2 and HP1β in SAHF (colocalization of H3K9Me2 and HP1β, respectively, with DAPI). coloc., colocalization.