Southern blot analyses were performed on genomic DNA isolated from bone marrow to determine the contribution to hematopoietic repopulation made by HSCs of either 129/SvJ wild-type or Hmgb3^-/Y origin (see “Materials and methods”). For each set of primary and secondary recipients, the mean percent and standard deviation of donor (Hmgb3^-/Y or 129/SvJ wild-type) derived bone marrow repopulation was determined as outlined in “Materials and methods.” Statistical analyses were performed using the Student t test (mean percent values) and F test (standard deviation).