(A) Fold change in expression of probe sets associated with NK cell differentiation or the cytotoxic effector program as measured by microarray analysis. (B) qRT-PCR analysis of Gzma, Gzmb, Gzmk, Prf1 and Tbet mRNA relative to Hprt mRNA in BM CD27+CD11b− NK cells from Ctrl (red) or RId2−/− (blue) mice. Representative of 3 experiments, N=3 per experiment. Error bars are S.D. (C) TBET, KLRG1 and IL-18R1 on CD27+CD11b− NK cells from Ctrl (shaded, grey) or RId2−/− (open, black) mice by flow cytometry. The open grey histogram is the FMO control. The MFI or percent positive cells is indicated for Ctrl (red) and RId2−/− (blue). Representative of 3–8 experiments. (D) Klr8−/− mice were injected with NK cells from the spleen of Ctrl or RId2−/− (CD45.2+) mice along with an equal number of WT CD45.1+ splenic NK cells and infected with MCMV. The percent of Ly49H+ NK cells in the spleen that were CD45.1+ (black gate) or CD45.2+ (red for Ctrl cells and blue for RId2−/− cells) was examined by flow cytometry on day 7. One representative experiment is shown. N=3. (E) Summary of data for multiple NK cell chimeric mice, set up as in (D). Each dot is one mouse. The mean +/− SD is shown. * P<0.05, ** P<.01, ***P<0.005.