Figure 3.

Chromosomal distribution of three groups of MNase-seq reads in lengths of >152, 147 ± 5, and <142 bp. A, Distribution of MNase-seq reads (data from leaf tissue) along chromosome 4 of Arabidopsis. The two horizontal bars represent the positions of the pericentromeric region and a knob located in the short arm of the chromosome (both are highly heterochromatic; Fransz et al., 2000). B, Distribution of MNase-seq reads along chromosome 4 of rice. The short arm and pericentromeric region of the long arm, both highly heterochromatic (Cheng et al., 2001), are marked by two horizontal bars. The x axes show DNA positions along the chromosomes. The y axes represent the normalized DNA fragment count ratio (“Materials and Methods”) of a specific group within 100-kb windows. Heterochromatic regions are enriched with reads >152 bp in both species.