Genealogical trees for the V_H and the V_κ rearrangements of case 2.

There were 38 cells with a V_H as well as a V_κgene amplificate (the names of the cells are given in the tree). For the V_H tree we made one correction of the tree generated by the software: one point mutation (71 C; see sequences available from the EMBL data library) was regarded as a shared mutation, although a group of cells had no mutation at this position. Consequently, we included 71 C as a mutation event in the construction of the genealogical tree. For the V_κ tree we made some modifications of the MacVector trees to aquire congruence of heavy and light chain genes: we observed a point mutation shared by 21 sequences incompatible regarding the construction of the V_H- and V_κ-based trees (see the 3 branches with f3-47, f1-21, and the branch with the assumed intermediate originating from f1-39). Therefore, it was assumed that this mutation happened 3 times independently. F3-22 was assumed to originate from f1-39, although the software-generated tree suggested another position. Importantly, the number of mutation events remained the same for this modification. For f1-27, f1-35, and f2-48, one backmutation was introduced in each of the V_κ sequences. See Figure 2 for additional explanations.