Pearl mice show a delay in virus control.C57BL/6, pearl, pearl-ash^+/−, ashen, and PKO mice were infected with 200 pfu of LCMV-WE and (A) virus titer in spleens were determined on days 4, 8, and 12 after infection. (B) Days 8 and 12 virus titers are shown for lung and liver. The means and the SDs are indicated. Graphs show pooled data of 2 independent experiments with 3-4 mice per group. For ashen mice data of 3 mice obtained in 2 different experiments are shown. The dashed lines indicate the detection limit.