Aggregation is mildly impaired in the absence of WASP.

B cells from WASP⁻ (▪) and WASP⁺ (■) mice were cultured for 46 to 50 hours with indicated stimuli. (A) Cells were photographed using a camera connected to an inverted microscope with a × 20 objective. Similar results were obtained in at least 5 experiments. (B) Aggregate cultures were gently resuspended, and single versus aggregated cells were enumerated. Mean values of triplicate experiments are shown. Error bars represent 1 SD, and at least 500 cells were counted in each group. Brackets indicateP < .07 using a 2-tailed t test. This observation is representative of 3 similar experiments.