Features of heterochromatin are concentrated on autosomal arms and the leftmost region of the X chromosome in C. elegans. (A) Chromosomal heatmaps depicting median Z-scores of ChIP-chip signal over 2-kbp regions for HPL-2, H3K9me1, H3K9me2, H3K9me3, H3K27me3, and LEM-2, along with standardized repetitive element densities and gene densities over 10-kbp regions. Red indicates enrichment, blue indicates depletion. HPL-2-enriched arms are marked by black bars. Validations of anti-HPL-2 antibody and ChIP-chip of HPL-2 from hpl-2 mutant embryos are shown in Supplemental Figure S1. (B) Genome-wide Pearson correlation coefficients (PCCs) for median Z-scores of ChIP-chip signal between pairs of the chromatin marks and genomic features shown in panel A. PCCs for regions that lie either in HPL-2-enriched arms or in chromosome centers are shown in Supplemental Figure S3. (C) Immunofluorescence images showing DNA (blue), H4K12ac (green), and HPL-2 (red) staining of wild-type hermaphrodite germline nuclei. Arrows point to paired X chromosomes. Scale bar, 2 μm.
