MZ B-cell development is highly dependent on Akt1/2. (A) Representative analysis of splenocytes from chimeras established with Akt1^+/+Akt2^+/− (top) or Akt1^−/−Akt2^−/− (bottom) progenitors 12 to 14 weeks previously. Viable donor-derived cells were gated as in Figure 1. Numbers in plots show the frequency of events as a function of the indicated parent gate. (B) Absolute cell numbers for respective splenic B-cell subsets were calculated using the gates shown in panel A. Error bars indicate the SEM for each group; n = 5. Data are representative of 2 separate experiments. *P ≤ .05.