Ab initio identification of a marsupial-specific imprinted gene via genome-wide histone state profiling in opossum fibroblasts
We generated genome-wide histone maps of four histone modifications, H3K4me3, H3K9Ac, H3K9me3, and H3K27me3, by ChIP-seq in male fibroblasts isolated from a model marsupial, Monodelphis domestica. We assayed the correlation and association of these histone modifications with each other, certain genomic elements such as CpG islands and predicted promoters, and the transcriptional states of the genes they mark. Generally, we found that promoters of actively transcribed genes are associated with H3K4me3 and H3K9Ac and lack H3K9me3 and H3K27me3. We also show that transcriptionally opposing, mutually exclusive histone modifications mark monoallelically expressed and imprinted genes in our samples. Overall design: Profiling of four histone modifications in adult ear fibroblasts of Monodelphis domestica by Illumina ChIP-seq.