Sequence data.

The number of raw sequence read pairs generated as well as the number of collapsed trimmed reads and the number of unique hits to reference genomes and passing quality filters are indicated. Endogenous DNA content was calculated by dividing the total number of unique hits passing quality filters and the total number of collapsed reads. BE: Blunt-End adapter ligation. AT: AT-overhang adapter ligation. The final concentration of adapter used for ligation is reported as standard (S) or low (L; see Material and Methods). C: Covaris sonication. B: Bioruptor sonication. N: Nebulization. While most DNA libraries were sequenced as Paired-End (2×100 cycles), one, indicated with an asterisk, was sequenced as Single-End. For this DNA library, #Collapsed refers to the numbers of reads considered post-trimming and not post-collapsing, as for other DNA libraries.