Cell type composition of hematopoietic organs from wt and bik−/− littermates. (A) The total number of bone marrow cells from 5- to 11-week-old wt (n = 6) and bik−/− (n = 8) mice was determined, and the numbers of pro- and pre-B cells (B220+ sIgM− sIgD−), immature and mature B cells (B220+ sIgM+ sIgD+), macrophages (Mac1+ Grl−) and granulocytes (Mac1+ Grl+) was determined by FACS analysis. (B) The total number of thymocytes from 5- to 11-week-old wt (n = 8) and bik−/− (n = 8) animals was determined, and the number of pro-T (CD4− CD8−), pre-T (CD4+ CD8+), and mature T (CD4+ CD8− or CD4− CD8+) cells was determined by FACS analysis. (C) The total number of splenocytes from 5- to 11-week-old wt (n = 8) and bik−/− (n = 8) animals was determined, and the number of naive and mature B cells (B220+ sIgM+ sIgD+), other B cells (B220+ sIgM− sIgD−), mature T cells (CD4+ CD8− or CD4− CD8+), macrophages (Mac1+ Grl−), and granulocytes (Mac1+ Grl+) was determined by FACS analysis. (D) Peripheral blood from 30- to 46-week-old wt (n = 6) and bik−/− (n = 9) littermates was examined, and the total number of lymphocytes and granulocytes (neutrophils, monocytes, eosinophils, and basophils) per milliliter was determined.