Conversion tracts in DT40 RAD51D and XRCC2 transfectants. (A) Schematic diagram of mutations in 31 Vλ regions from DT40 RAD51D-GFP transfectants, aligned with the germline Vλ region (top). Complementarity-determining regions (CDRs) which make major contacts with antigen are indicated. Each Vλ sequence is represented as a horizontal line; bars identify gene conversion tracts (black, 2 or more nt differences with germline; gray, one nt difference); and lollipops identify point mutations with no match in the germline sequence. Potential ψV donors for each converted tract are identified above the bars. Range and average length of conversion tracts indicated below. (B) Schematic diagram of mutations in 27 Vλ regions from DT40 XRCC2-GFP transfectants, aligned with the germline Vλ region (top line). Notations as in panel A. (C) Pie chart showing relative fractions of gene conversion events resulting in changes at 1 nt or 2 or more nt, in Vλ genes from DT40 RAD51D-GFP and DT40 XRCC2-GFP transfectants.