Phenotypic characterization of developing NK cells in CD45-congenic HSCT. Lethally irradiated B6 (H-2^b, CD45.2) mice were transplanted with 5 × 10⁶ Ly5.2 congenic (H-2^b, CD45.1) BMCs depleted of NK and T cells. Splenocytes of B6 (H-2^b) recipients were stained for CD45.1, NK1.1, CD3, Ly49C/I, Ly49G2, Ly49A, Ly49D, CD94, DX5, NKG2A, CD27, Thy1.2, CD11b, and CD43 at day 14 after congenic BM transplantation and compared with untreated control mice. Gated CD45.1⁺NK1.1⁺CD3⁻ cells are shown. (A) Frequencies of NK cells positive for CD94, DX5, CD11b, and CD43. (B) Frequencies of CD94^dim and CD94^bright NK cells. (C) Frequencies of NK cells positive for NKG2A. (D) Proportions of NK cells expressing CD27 and CD11b. (E) Frequency of Thy1.2⁺ NK cells. (F) Thy1.2 density shown as MFI on control (tinted gray) and transplanted (solid dark line) mice. The numbers represent the percentages of cells positive for the mentioned markers or MFI values. Data are representative of 5 experiments using 3-4 mice per group in each experiment.