Hybrid IGKV sequences from multiplex PCR IGKV-IGKJ5. Examples of sequences from the cloned PCR products obtained from interleukin-1α (IL-1α) or lipopolysaccharide (LPS) -treated human pre-B 697 cells. Seven chimeric sequences were selected to illustrate different examples of IGKV type 2 replacement in terms of localization, in particular: from the FR to CDR targeted regions, internal replacement and IGKV gene usage as either a recipient or donor sequence. IMGT/V-QUEST38–33 was used for alignment with IGKV germline genes. IGKV-IGKJ5 rearrangements were identified as follow: on the alphabetic sequences of the cloned PCR products, dark green corresponds to IGKV genes, IGKJ5 sequences are shown in blue, and P- and N-diversity are shown by orange and red letters, respectively. The figures in brackets indicate the number of nucleotides deleted during the initial IGKV-IGKJ rearrangement. The lower aligned reference sequences are represented as dashes in cases of a perfect match and as letters in cases of discordance. The IGKV genes initially rearranged with the IGKJ5 gene (recipient IGKV gene) are shown in green and the donor IGKV genes replacing the initial rearranged recipient IGKV gene are shown in blue. Superimposed blue and green sequences indicate regions of sequence identity (not assigned). Potential AID hotspots (WRCY/RGYW motif with W:A/T; R:A/G; Y:C/T) are underlined and in bold.