Figure 3.—

Whole-nucleus distribution of histone H3K9 and K27 mono-, di-, and trimethylation at pachytene. Methylated histone H3's are shown in green, DAPI (DNA) in red, and CENP-C (kinetochores) in blue. (A) H3K9me1 stains heterochromatin in a spotty pattern. (B) H3K9me2 stains euchromatin (i.e., regions that do not stain well with DAPI). (C) H3K9me3 stains euchromatin weakly. A 2× magnification of centromere staining with this antiserum (boxed region) is shown in Figure 7C. (D) H3K27me1 stains chromosomes uniformly. The boxed region is also shown as a 2× magnification in Figure 4A. (E) H3K27me2 stains heterochromatin. (F) H3K27me3 staining is enriched in several focused domains (one is shown in the center, arrow). Arrowheads indicate knobs.