Characterization of the diverse phenotypes associated to alterations of GALC expression in murine and human HSPCs. (A,D) Experimental schemes. (B) GALC activity (measured as fold to mock-transduced Galc+/+ cells) and LV copy number (VCN) measured on the in vitro progeny of murine Galc−/− and +/+ HSPCs transduced with the indicated LV and exposed or not to IGF1 after transduction. n ≥ 3 in each group. (C) Number (#) of colonies retrieved from colony-forming cell assays performed with murine HSPCs obtained from Galc−/− and +/+ mice after transduction with the specified LV and exposed to IGF1 after transduction, if indicated. n ≥ 3 in each group. (E) Survival curves of FVB/Twi Galc−/− and +/− mice after the intraperitoneal transplantation of Galc−/− HSPCs transduced with the indicated vectors and exposed to IGF1 after transduction, if indicated. n ≥ 3 in each group. (F-G) Engraftment failure frequency (F) and transduced cell engraftment (VCN in the BM; G) at 20 and at 120 days after transplantation or at death as in (*), measured in the same experimental groups as in panel E. (§) Similar results were obtained with +/+HSPCs. (H-I) TUNEL assay performed on murine (H) and human (I) HSPCs obtained from Galc−/− and +/+ mice and from normal donors (nd) CB and GLD patients' BM, 2 and 5 days (d) after transduction with the specified LV and exposed to IGF1 after transduction, if indicated. Percentage of TUNEL⁺ nuclei over the total number of nucleated cells is reported (≥ 8 fields and ≥ 100 cells were counted per condition). n ≥ 5 individual experiments per condition, average values ± SD are reported. *P < .05, **P < .01, ***P < .001 on 1-way ANOVA.