FIG. 6.

Insertions at atypical integration sites. Insertions 22, 64, and 65 (A, B, and C, respectively) occurred at sequences that do not resemble an L1 EN consensus cleavage site. Each event resulted in the deletion of target site nucleotides, and the sizes of the deletions are indicated below the respective preintegration sites. A 55- to 59-bp MaLR sequence is located at the 5′ genomic DNA/L1 junction in insertion 22 (depicted by a white box). An endogenous L1 (gray rectangle) was completely replaced by the newly integrated L1 in insertion 64, and three untemplated base pairs are present at the L1/3′ genomic DNA junction. A 292- to 527-bp segment of endogenous L1 (gray rectangle) is located at the 5′ genomic DNA/L1 junction in insertion 65. The origin of this DNA segment remains unknown. Small arrows indicate the positions of PCR primers used to characterize the insertions.