L1 endonuclease (EN) cleavage site analyses at the 5' and 3' junctions. For both the 5' and 3' target sites of each locus, the last four nucleotides of the target site and first nucleotide of the flanking sequence were compared to the canonical L1 EN cleavage motif (5'-TTTT/A-3'). To investigate the possibility that the candidate L1s were inserted in the antisense orientation, the 5' target site was reverse complemented and analysed. The black bars show the frequency of each divergence value at the 3' target site among our 39 loci, while the blue bars show values for the 5' target sites. The 3' target sites show more divergence from the typical EN cleavage motif than the 5' target site.