Figure 4. Incomplete symmetric excision event of a REP doublet detected in Illumina sequencing data. The first line of the alignment shows the genomic sequence of SBW25 from position 598,553 to position 598,634. The second line of the alignment shows part of the sequence read that maps perfectly to the corresponding genome sequence apart from the excision in the center of the read. The cartoon below the alignment shows the general composition of the GI REP doublet. The last line in the picture shows the remaining REP sequence found in the sequence read. It only contains flanking sequence (a), the central palindrome and flanking sequence (ac).