FIG. 9.

HP1βΔN does not affect senescence-associated cell cycle arrest and expression of SA β-gal. (A) WI38 cells stably infected with an HP1βΔN-expressing retrovirus or a control (Cont or Con) virus were infected with viruses encoding activated Ras or a control virus. The infected cells were selected with 3 μg/ml puromycin and 500 μg/ml G418. Eight days later, the cells were pulse-labeled with 5′-bromodeoxyuridine (BrdU) for 1 h and stained with antibodies to 5′-BrdU. (B) One hundred cells shown in panel A were scored as 5′-BrdU positive or negative. (C) Cells shown in panel A were stained to detect expression of SA β-gal (blue).