Loss of the Bcl2 ARE-rich sequence confers a competitive disadvantage to B cells.

<p><b>A</b>, Flow cytometry analysis of competitive bone marrow chimeras. BM cells from B6.SJL and mb1^cre mice (control group) or B6.SJL and Bcl2-ARE^flox/flox x mb1^cre mice (ARE^∆/∆ group) were mixed in a 1 to 1 ratio and injected into lethally irradiated B6.SJL mice. Blood samples were taken after eight weeks of BM reconstitution for flow cytometry using CD19, CD3 and CD45.2 as cell markers. <b>B</b>, Analysis of B and T cell proportions in BM chimera mice. A Mann-Whitney non parametric test was performed for statistical analysis of the data. P values are indicated. n = 8–9 mice per genotype. <b>C</b>, Analysis of B and T cells present in peripheral LNs of the mice described in A. Representative pseudo-colour dot plots are shown. <b>D</b>, Quantitation of B and T cell proportions in LNs. <b>E</b>, Survival analysis of LN B cells from C57BL/6, Eμ-bcl2–36, Bcl2-ARE^flox/flox x mb1^wt (flox/flox) and Bcl2-ARE^flox/flox x mb1^cre (∆/∆) mice. B cells were cultured <i>in vitro</i> in the absence of cytokines. Cell survival was tested at the indicated times by DAPI staining. A Mann-Whitney test was performed for statistical analysis of the data.