Retroviral reconstitution of ST3Gal-IV KO cells partially corrects the defect in T-cell development. (A) Schematic illustration for the generation of retrogenic MBMC mice as described in the main text. Fold increase of T and B cells (B) or thymocyte subsets (C) within the reconstituted ST3Gal-IV–deficient mice-derived cell populations in the reconstitution group (purple) compared with the ST3Gal-IV–deficient mice-derived cell populations in the control group (light green) set to the value of 1. Bars represent the mean ± SEM of 3 independent experiments with 11 to 17 mice per group. **P < .01 and ***P < .001 by 2-tailed Student t test.