FIG. 3.

Chimeric L1 insertions associated with genomic deletions. Insertions 60, 61, and 62 (A, B, and C, respectively) resulted in the formation of chimeric L1s and the concomitant deletion of target site nucleotides. Each insertion initiated by TPRT then likely was joined to target site DNA by single-strand annealing (the process is depicted in full in panel A). The undulating and straight black lines represent L1 mRNA and minus-strand L1 cDNA, respectively. The gray rectangles represent endogenous L1s, and “Am” represents the position of their poly(A) tails. The upward-pointing open-headed arrow indicates the L1 integration site. The gray/black-shaded rectangle indicates the resultant chimeric L1. “An” indicates the poly(A) tail at the end of the newly integrated L1. Small horizontal arrows indicate the positions of PCR primers used to characterize the insertion. The sizes of the target site deletions (in base pairs) are indicated in each panel.