FIG 4.

Donor site segments and position by V region. (A) The number of donor site contribution segments in each high-confidence variable region sequence was determined in blastn output across the 41 samples. Usage was determined by the sum percentage of variable region sequences by segment. For instance, V1 has the greatest number of variable region sequences where only one donor site segment is used in a given V region sequence, consistent with its overall lack of diversity. (B) The position of donor site contributions within a variable region sequence was also determined for each donor site (i.e., “first” means the donor site was found to align to the 5′-most segment of the variable region sequence, “second” means the donor site was found to align to the central segment of the variable region sequence, and “third” to the 3′-most segment of the sequence). Within-sample percentages were summed for each variable region in order to adjust for differences in read coverage at each locus between samples. These summed percentages were then adjusted by the total summed percentage to add up to 100% for each variable region.