Fig. 1.
BMR fibroblasts display a unique concerted cell death phenotype. All cells were cultured at 3% oxygen concentration. (A) Fibroblasts of both S. judaei and S. golani species become confluent at high cell density and do not undergo early contact inhibition typical of naked mole rat cells. Cells were seeded at 5 × 105 cells per 10-cm dish and photographed at indicated time points. (Magnification: 100×.) (B) BMR fibroblast cultures undergo CCD irrespective of growth conditions. Mouse, denotes mouse fibroblasts, and NMR denotes naked mole rat fibroblasts cultured under our standard conditions of 15% FBS and EMEM media from ATCC. Blue growth curves correspond to BMR fibroblasts cultured in different concentrations of FBS and either EMEM media from ATCC or low-serum fibroblast growth media (FGM) from Lonza. FGM media was used with different concentrations of fibroblast growth factor indicated by (no. in blue) -F or 1/2F (1), 15% FBS, FGM (2), 15% FBS, FGM-F (3), 2% FBS, FGM (4), 15% FBS, EMEM (5), 2% FBS, FGM 1/2F (6), 5% FBS, EMEM (7), 0% FBS, FGM. BMR cells grew rapidly for several PDs, then invariably stopped proliferation and underwent CCD.