Hematopoietic differentiation of MPS-iPS cells. (A) Embryoid bodies were derived from iPS cells and induced to differentiate into hematopoietic cells. (B) Cells were harvested and assayed for expression of hematopoietic markers CD45 and CD34. No statistically significant differences were found when hematopoietic progeny of the MPS-iPS cells and gene-corrected MPS-iPS (MPS iPS IDUA) cells were compared as determined by CD34 expression (mean ± SEM, 9.2 ± 1.4 vs 13.5 ± 2.5), CD45 expression (17.0 ± 4.5 vs 18.2 ± 2.1), and simultaneous expression of CD34 and CD45 (4.5 ± 0.8 vs 5.7 ± 1.6; all P > .05). These data did not differ significantly from the CD34 and CD45 expression of the hematopoietic progeny of wild-type iPS cells and in iPS cells of any genotype at early (< 20) passage and late (> 20) passage iPS (data not shown). (C) Quantitative PCR analysis of BRACHYURY, TAL-1, GATA-2, CD34, and CD38 expression levels in wild-type iPS cells (IPS, green bars), hematopoietic progeny of wild-type iPS cells (heme IPS, red bars). and CD34⁺ cord blood cells (CB; black bars). (D) Quantitative PCR analysis of the same gene set in the MPS-iPS cells (IPS, green bars), hematopoietic progeny of gene-corrected MPS- iPS cells (Heme IPS, red bars), and CD34⁺ CB cells (black bars). Expression of all these genes in iPS cells of both wild-type and mutant genotype (each set arbitrarily to equal 10¹) was significantly elevated after induction of hematopoietic differentiation mirroring expression of these genes in hematopoietic progenitor cells derived from human CB. All values were normalized against endogenous GAPDH expression. (A) Images were obtained with a Nikon Eclipse TS100 scope, magnification 10×/0.25. Images were taken with a Nikon Coolpix 4300 digital camera with a microscope adaptor from Martin Microscope MMCOOL S/N:1228 Nikon UR-E4. All images were taken at room temperature.