B cell ontogeny in the bone marrow of BLT mice follows canonical patterns.

<p>(<b>A–B</b>) Flow cytometry and scatter plots reveal the relative paucity of mature B cells in the BM as defined according to CD10 and CD20 expression. (n = 15; 1 way ANOVA with Bonferroni's multiple comparisons tests). (<b>C–D</b>) Flow cytometry and scatter plots reveal that, as expected, immature B cells exhibited higher levels intracellular TdT expression, a protein that is active during B cell receptor rearrangement. (n = 15; 1 way ANOVA with Bonferroni's multiple comparisons tests). (<b>E–F</b>) Flow cytometry and scatter plots for CD10 expression show that the majority of BLT mouse BM CD19⁺ cells are Pre-B/Immature B cells. (n = 13, <i>t</i>-test). (<b>G–H</b>) More BLT mouse Pre-B/Immature B cells identified in (E–F) express the pre-B cell receptor surrogate light chain component lambda 5 than CD10^neg mature B cells. (n = 4, <i>t</i>-test). (<b>I–J</b>) Conversely, more CD10^neg mature B cells expressed intracellular IgM than did the Pre-B/Immature B cells present in BLT mouse BM (n = 13, <i>t</i>-test). ** indicates a p value less than 0.01. *** indicates a p value less than 0.001.