Fig. 2.

Characterization of the Drosophila melanogaster methylome. (A) Average methylation levels were determined for all cytosine residues and then distributed into bins with increasing methylation ratios (blue bars). For comparison, the corresponding data are also shown for human sperm DNA that was spiked into the Drosophila sample before bisulfite conversion (black bars). The actual numerical values of the first bins are 99.7% (Drosophila) and 92.9% (human sperm). (B) Dinucleotide sequence context of unconverted cytosines in Drosophila (blue) and in human sperm (black). (C) Position-specific nonconversion ratios (red) and coverage (gray) of the Drosophila Invader4 element. Results are shown for the sequence with the lowest conversion rate among genomic Invader4 elements. The specific region previously reported to be methylated (24) is indicated as a green bar. Sequence position numbers refer to GenBank accession AE014135.3.