Beige^J and souris mice reproduce the clinical and immunologic phenotype of CHS. (A) Top panel: Diluted coat color of beige^J and souris mice. Middle panel: Uneven distribution of pigment in the hair shafts. Bottom panel: Typical inclusion bodies in granulocytes (white arrows). (B) Scheme of the LYST protein with indicated mutation sites in souris and beige^J mice. The mutation of souris mice is shown on genomic DNA level (position 92815; NCBI Reference Sequence NC_000079), whereas the beige^J mutation is shown on cDNA level (NCBI Reference Sequence NM_010748.2). (C-E) NK-cell degranulation and cytotoxicity. Mice were injected intraperitoneally with polyinosinic acid/polycytidylic acid, and spleen cells were analyzed 24 hours later. (C) Representative FACS plots of NK-cell degranulation showing CD107a surface expression on NK1.1⁺CD3⁻ cells after restimulation with YAC-1 cells or medium control. (D) Degranulation is shown as percentage increase of CD107a expression on NK1.1⁺CD3⁻ cells (ΔCD107a) after restimulation with YAC-1 cells compared with medium control. (E) Lytic activity of NK cells on YAC-1 target cells as determined in a ⁵¹Cr-release assay. (D-E) Data show results from one of 2 independent experiments with 3 mice per group. ***P < .001.