In vivo loss of NK cells that bind to D^d. Fresh splenocytes from mice of the indicated strains were evaluated by flow cytometry for expression of the NK cell marker DX5 and either 4E5 (Ly-49D) or 4D11 (Ly-49G2). FVB, MHC-D^d, and D^d-ζ splenocytes did not show detectable levels of A1 (Ly-49A) or 5E6 (Ly49-C&I) staining (unpublished observations, February 22, 2000). The D^d-ζ cells were obtained from 130 strain mice.