Figure 2
Chromosomal localization of ATRX and histone H3 tri-methylation on lysine 9 (H3K9 me3 ) in neonatal spermatogonia. A) Analysis of histone methylation patterns revealed that in spite of the absence of global DNA methylation (red) at pericentric heterochromatin (thin arrow), H3K9me3 (green) remained associated with centromeric domains in the chromosomes of neonatal spermatogonia. Importantly, H3K9me3 is also preferentially associated with one of the unmethylated chromosomes on each spread analyzed (bold arrow). B) In contrast, H3K4me2 (green) remains associated with entire chromatids in the majority of chromosomes (thin arrow). However, one of the unmethylated chromosomes was consistently found to be completely devoid of H3K4me2 (bold arrow). C) Notably, the chromatin remodeling protein ATRX (green) remains associated with pericentric heterochromatin and consistently marks a single unmethylated chromosome on each metaphase spread analyzed. Scale bar = 10 μm.