pYB1761 H3K9me2
Epigenetic regulation of heterochromatin in the fission yeast Schizosaccharomyces pombe relies on histone H3 lysine 9 methylation (H3K9me), which recruits silencing factors and contributes to nuclear organization. To investigate the distribution of heterochromatic marks on the exoDNA plasmid pYB1761, we performed chromatin immunoprecipitation followed by sequencing (ChIP-seq) for H3K9me2 in wild-type cells, together with matched input DNA controls. Cultures were grown in YES medium at 30 °C to mid-log phase, and chromatin immunoprecipitation was carried out using a monoclonal anti-H3K9me2 antibody (Abcam, catalog AB1225).  Library preparation and sequencing were performed by Novogene. Four independent biological replicates were pooled per sample (5 OD600 for input DNA, 15 OD600 for H3K9me2 ChIP IPs). DNA fragments were end-repaired and A-tailed prior to ligation with Illumina-compatible adapters. After size selection, libraries were amplified by PCR, pooled, and sequenced on an Illumina NovaSeq-6000 platform. Sequencing was performed with paired-end reads, and raw data were processed using a standard bioinformatics pipeline: read quality assessment with FastQC, adapter and index trimming with Trimmomatic, and mapping to the S. pombe reference genome (ASM294v2) using BWA. Aligned reads were normalized using bamCoverage (RPKM), and visualization was performed with IGV in 50 bp bins.  This dataset includes raw FASTQ files for H3K9me2 ChIP and input controls, as well as associated metadata. The data provide a resource for studying heterochromatin formation and plasmid-associated chromatin states in fission yeast.