Study of the epigenetic signals in the human genome

Abstract

Epigenetics can be defined as changes in the genome that are inherited during cell division, but without direct modification of the DNA sequence. These genomic changes are supported by three major epigenetic mechanisms: DNA methylation, histone modification and small RNAs. Different epigenetic marks function regulate gene transcription, some of them when altered can trigger various diseases such as cancer. This work is focus on the epigenetic signals in the human genome, studding the dependency between the nucleotide word context and the occurrence of epigenomic marking. We based our study on histone epigenomes available in the NIH Roadmap Epigenomics Mapping Consortium database that contains various types of cells and various types of tissues. We compared genomic contexts of epigenetic marking among chromosomes and among epigenomes. We included a control scenario, the DNA sequence regions without epigenetic marking. We identified significant differences between context occurrence of control and epigenetic regions. The genomic words in epigenetic marking regions present significant association with chromosome and histone modification type.