NK-cell subsets in the fetal liver and spleen. Representative FACS profiles (A) and total numbers (B) of CD3⁻CD122⁺NK1.1⁺DX5⁺ iNK and (C-D) CD3⁻NK1.1⁺CD43⁺Mac-1⁺ mNK cells at the different time points in the fetal liver. Data represent mean ± SD values from 5 to 14 livers analyzed in 12.5- to 18.5-day-old fetuses from 3 to 4 litters. Numbers in FACS profiles are mean frequencies of cell populations within the indicated gates, relative to total liver cells. Profile from the adult BM is included as a control. Representative FACS profiles of (E) CD3⁻NK1.1⁺DX5⁺ iNK cells and (F) CD3⁻NK1.1⁺CD43⁺Mac-1⁺ mNK cells in the fetal spleen. (G) Total number of fetal spleen cells, and (H) total number of iNK and (I) total number of mNK cells in the fetal spleen. Data represent mean ± SD values from 5 to 6 spleens analyzed in 14.5- to 18.5-day-old fetuses from 2 litters. Two spleens were pooled for the analysis. Profile from the adult spleen is included as a control; 0 indicates values below the detection level. *P < .05, **P < .01, and ***P < .0001. ns indicates not significant.