
Frequency of L1 elements in different GC fractions of the human genome. The % GC was calculated over 20-kb windows. The bins from left to right correspond to an increasing 2% GC fraction. The family-specific L1 curves were built using the DNA flanks of 299 Ta-1 (squares), 300 L1PA2 (triangles), and 324 L1PA5 (diamonds) inserts. The total genome curve (heavy line) was built using Tables “gcPercent” at http://genome.ucsc.edu/ for all chromosomes.











