Figure 5.

The dnRAG1 CD19⁺ B220^lo B-cell repertoire is largely unmutated and exhibits biased usage of Vκ19–32 and Jκ1 gene segments. (a) Wild-type (WT) and dnRAG1 splenic CD19⁺ B220^hi and CD19⁺ B220^lo B cells were isolated by FACS for preparation of genomic DNA or total RNA. Post-sort purity was routinely > 97%. (b) Genomic DNA prepared from sorted B cells shown in (a) was analysed for V_H to DJ_H and Vκ to Jκ rearrangements as in Fig. 4. (c) Igκ cDNAs prepared from total RNA isolated from sorted B cells indicated in (a) were amplified, cloned, and sequenced to determine Vκ and Jκ gene usage (top panel and lower left panel, respectively) and mutation status (lower right panel).