Centromeric and heterochromatic DNA sequences of Crassostrea gigas

Composition of DNA sequences underlying the active centromeres and H3K9me3-marked heterochromatic regions have not been explored in the Pacific oyster, despite the existing genomic data in the form of scaffolds and pseudochromosomes because the annotation of the parts of the genome enriched in repetitive sequences still faces serious problems. Thus, those parts are frequently left out from genome assemblies. In order to investigate DNA composition of genomic regions associated with the two specific chromatin types, we employed chromatin immunoprecipitation followed by high-throughput next-generation sequencing of the Cg-CenH3- and H3K9me3-associated sequences.