Figure 2. MBL subject with intraclonal diversification.

In A, genealogical analysis of related MBL subgroups based on sequences from 37 single MBL cells from subject 0602, and analysis of the rearranged immunoglobulin V_H3-07 heavy and V_L1b light chains from each MBL cell subgroup. Letters A — L represent individual subgroups of MBL cells with a related immunoglobulin heavy chain gene and light chain rearrangement. The number of individual cells identified from each subgroup is shown in orange to the right of the subclone sequence. GL represents the germline V_H3-07 sequence. Empty circles with dashed lines (representing multiple potential clones) and circles with dashed lines labeled H1, H2 and H3 (individual clones) represent hypothetical transitional MBL clones that were not observed in the analysis. In B, antigen drive analysis with p values calculated using the method of Lossos et al (2000) (23). In brief, the ratio of amino acid replacement (R) to synonomous (S) nucleotide base changes is compared in both the framework (Fr) and complementarity determining region (CDR) to determine if the observed mutations are random or antigen driven (21).