(A) Hierarchy of differentiation for immune cell progenitors. Bone marrow was harvested from SPF (black) and NME (green) pups at day of life (DOL) 3 and (B) LSK (Lin− Sca-1+ c-Kit+), (C) HSC (Lin− Sca-1+ c-Kit+ Flt-3− CD34−), (D) MPP4/LMPP (Lin− Sca-1+ c-Kit+ Flt-3hi), (E) GMP (Lin− Sca-1− c-Kit+ CD16+ CD34+), (F) MEP (Lin− Sca-1− c-Kit+ CD16− CD34−), (F) CLP (Lin− Sca-1− c-Kit− Flt3+) were enumerated flow cytometrically. 8-14 mice/group. Data was collected from 2-3 separate experiments. Example flow plots are from a DOL 3 NME mouse. Statistical analyses were determined using Mann-Whitney Test.