Hematopoietic cell production, CFU-GM production, and telomere length of hematopoietic cells in wildtype, G3, and G6 mTerc−/− LTBMCs from different generations and genetic backgrounds.
Cultures were established from G3 and G6 mTerc−/− B6/Sv mice (panels A-C) or G3 mTerc−/− B6 mice (panel D) and were maintained in Myelocult M5300 medium plus 10−6 M hydrocortisone at 32°C, with weekly exchange of half of the medium. (A) (B) Total cells (panel A) and total CFU-GMs (panel B) in suspension per culture flask, were evaluated at weekly intervals. (C) At 5 weeks after initiation of the culture, the stromal layer of LTBMC was detached, and total CFU-GMs in stroma were evaluated. (D) Telomere fluorescence of total BM cells at the time of establishing LTBMC (day 0) was evaluated by flow-FISH (black bars); at the end of the cultures (day 35), telomere length of hematopoietic cells in suspension cells (gray bars) and hematopoietic cells in stroma (white bars) was also evaluated by gating the population of intermediate forward light scatter and low right-angle light scatter, characteristic of lymphoblastoid hematopoietic cells. Results are expressed as the mean ± SD of 3 different experiments *P < .01; mTerc−/− versus wildtype animals, for panels A-C; day 35 versus day 0 telomere length, for panel D.
