Generation of iPS cells from BM hematopoietic progenitor cells. (A) FACS strategy to isolate candidate iPS cells from HSPCs. HSPCs were transduced with retroviruses expressing GFP, Oct3/4, Klf4, c-Myc, and Sox2 for 2 days and subsequently cultured for 14 days in ES cell conditions. On day 14, candidate iPS cells were isolated by FACS based on a GFP-CD45-EpCAM+SSEA-1+ phenotype and cultured in individual wells (25 cells sorted per well) until single iPS colonies emerged. (B) Representative FACS plots of a commercially available C57BL/6 ES cell line (Primogenix B6N1, left), and an established iPS line showing the simultaneous expression of EpCAM and SSEA-1 (right). (C) Expression of pluripotency factors and induction of Nanog expression in established iPS lines (5 independent experiments, 3 replicates/cell line). (D) Correlation plots of the genome-wide expression patterns of young and aged BiPS lines to ESCs (1 experiment, relative expression values were averaged from 2 replicate arrays per condition). A correlation plot of expression patterns in ESC to HSCs is also shown to highlight the similarity in expression patterns of iPS lines and ESCs. (E) Y chromosome fluorescent in situ hybridization of a cross-section of the hippocampus from a negative control female mouse (top) and an aged^BiPS primary chimera (bottom) generated from male aged^BiPS cells injected into a female blastocyst. (F) FACS plots showing the congenic immunophenotype (CD45.1/CD45.2 system) of the hematopoietic cells used for cell isolation and primary chimera generation (bottom right). Peripheral blood phenotype of a germline contributed aged^BiPS offspring.