Effect (mean + SEM) of ovx on the expansion of ST-HSPCs and LT-HSPCs in T cell–replete and T cell–deficient mice. (A-C) Effects of ovx on the relative frequency of CD150⁻CD48⁻ LSK cells (ST-HSPCs/MPPs) and CD150⁺CD48⁻ LSK cells (LT-HSPCs) in WT, TCRβKO, and TCRβKO mice previously reconstituted with T cells. (Left) Representative flow cytometric dot plots from 1 mouse per group using the signalling lymphocyte activation molecule receptors CD150 and CD48. Parent population is Lin⁻Sca1⁺c-Kit⁺. The upper boxes delineate LT-HSPCs. The lower boxes delineate ST-HSPCs + MPPS. (Right) Mean + SEM for each group. Data are expressed as percentage of BMMCs. n = 10 mice per group. (D-I) Effect of ovx on peripheral blood cell expansion after primary competitive repopulation. The panels show the percentage of CD45.2⁺ myeloid cells (CD11b⁺), granulocytic cells (GR-1⁺), and B lineage cells (B220⁺) in the peripheral blood of lethally irradiated WT recipient mice that received CD45.2⁺ BM donor cells mixed in a 1:2 ratio with CD45.1⁺ competitor BM cells. CD45.2⁺ BM cells were obtained from WT, TCRβKO, and reconstituted TCRβKO mice subjected to sham operation or ovx 2 weeks earlier. CD45.1⁺ BM cells were obtained from intact WT mice. *P < .05 compared with the corresponding sham-operated group.