SOX11 expression leads to clonal expansion of B cells. (A) Deep sequencing of the genomic DNA from B1a cells showing increased IgH gene clonality in Tg-SOX11 mice vs WT mice. (B) Decreased total productive rearrangements in the BCR repertoire of B1a cells of Tg-SOX11 mice vs WT mice showing a decrease in IgH gene diversity. (C) Frequency of the top 10 rearrangements compared with all other rearrangements of the IgH locus in B1a cells showing clonality in 2 Tg-SOX11 mice and oligoclonality in 2 Tg-SOX11 mice vs normal IgH diversity in the 2 WT mice. (D) Productive frequency of the top 100 IgH gene rearrangements shows loss of IgH diversity in all Tg-SOX11 mice (N = 4) as compared with WT mice (N = 2). In the histogram, each color represents a unique IgH clone, whereas the numerals represent the frequency of top clone in each mouse.