epigenome

Studying zebrafish embryos, researchers at Washington University School of Medicine in St. Louis have shown that the epigenome plays a significant part in guiding development in the first 24 hours after fertilization. The research may deepen understanding of congenital defects and miscarriage.

The genome is the instruction book for life. But reading that instruction book and carrying out its directives are controlled by the epigenome, which attaches chemical markers to DNA to activate or silence genes. For the first time, researchers at the School of Medicine and elsewhere have assembled a comprehensive map of the human epigenome. 

A Washington University in St. Louis team is participating in the modENCODE project, a massive ongoing effort to map all the elements in model organisms that affect whether genes are silenced or expressed. The work supports the more complex ENCODE project, which is tasked to map the same elements in the human genome. While the genome is the same in every cell, each cell type expresses a different set of genes. In people, moreover, roughly 95 percent of the genome is silenced. Together the projects will “put flesh on the bones” of the Human Genome Project, says team leader Sarah C.R. Elgin.