CD43⁺ B cells accumulate in the bone marrow of TgE Notch1^lox/lox CD19^+/Cre mice. Total cells isolated from the bone marrow of each indicated genotype were stained with B220 and CD43 fluorochrome-conjugated antibodies and analyzed by flow cytometry. Live cell populations, designated by forward and side scatter properties, were gated and B220 and CD43 expression was examined. A representative dot plot for each genotype is shown (A). (B) The average percentage of B cells in the bone marrow that express CD43 is shown plus or minus SE. Populations are represented as the percentage of total bone marrow that is CD43⁺ (% total) as well as the percentage of B cells that are CD43⁺ (%B220). *P = .05, **P = .04 by t test. Notch1^lox/lox, n = 5 mice; Notch1^lox/lox CD19^+/Cre, n = 5; TgE Notch1^lox/lox, n = 8; TgE Notch1^lox/lox CD19^+/Cre, n = 11.