FIP200 is essential for the maintenance of fetal HSCs. (A) Diagram of the competitive repopulation experimental design for data in panels B-C. Fetal liver cells (200 000) from CD45.2⁺ control or CKO mice were injected into lethally irradiated CD45.1⁺ wild-type recipients along with 500 000 CD45.1 bone marrow cells. Reconstitution of peripheral blood by donor cells was monitored for 16 weeks after the transplantation. (B) Contribution of fetal liver-derived CD45.2-expression (donor) cells to peripheral blood leukocytes in reconstituted mice. (C) Contribution of donor cells to peripheral multilineages, including myeloid lineage (Mac1⁺, Gr1⁺), B-cell lineage (B220⁺), and T-cell lineage (CD3⁺). Data represent the average donor chimerism levels from 3 independent experiments with a total of 12 recipients per genotype.