SADS is a property common to multiple different senescence models and pathways. (A and B) SADS is present in a SMURF2-induced senescent BJ fibroblast, yet these cells do not form SAHF (B). (C and D) Oxidative stress-induced senescence of a Tig1 fibroblast results in distension of α-sat (green) and sat II (red) in a cell with SAHF (DAPI; D). (E and F) Quantification of SADS and SAHF in LF1 and BJ fibroblasts, induced with wild-type SMURF2 (n = 200, representative of one of three repeats). (G) Tig1 fibroblasts with SADS (green) may or may not be positive for p21 staining (red). (H–J) SADS in LF1 p21 knockout cells are quantified (n = 204; J) and a SAHF-positive senescent cell is shown (H and I) with α-sat (green), sat II (red), and DAPI (I).