After the term ‘epigenetics’ was introduced in 1942 in the context of developmental studies, the meaning of epigenetics has undergone a major paradigm-shift over time. Over the last 40 years or so, epigenetics has gradually evolved from a phenomenon to a modern field of research. Epigenetics holds great promise, particularly in complementing genomics, in understanding the normal and diseased state of life. The combination of all epigenetic modifications in a genome constitutes the epigenome. An epigenome adds an additional layer of regulatory complexity to the genome of an organism by editing and modifying the language of the genome written in its DNA sequence. The fact that various epigenetic modifications (epigenetic marks) can be transmitted transgenerationally makes the study of epigenetics important.
Currently, epigenetics is going through a major documentation phase, which is typical of a rapidly evolving science. However, despite great progress in recent years in understanding various facets of epigenetics, including the molecular mechanisms of epigenetic regulation of gene expression, we are far from understanding the genome-epigenome interaction and how it can shape the plasticity, adaptability and evolvability of life. We are even struggling to understand whether epigenetic changes can be separated as adaptive, versus adverse epigenetic changes. Based on the current direction of research, there is reason to hope that these issues will be addressed in the near future.
Historically, whenever a field in life science has made such remarkable progress within a short period of time, it has rekindled a lot of hope about revolutionizing the understanding of basic sciences as well as clinical sciences. Epigenetics is no exception to this tradition. The hope about personalized medicine and nutrition that was raised following the sequencing of the human genome has been renewed with the advances in epigenetics/epigenomics. Naturally, it is a logical step for the scientific community to assess the progress and the state of the science and be able to differentiate the hype from the hope surrounding its potential utility in benefiting mankind.
This special issue is an attempt to capture an essence of epigenetics through various articles written by experts in the field. Some articles specifically highlight the potential utility of epigenetics in toxicology. The articles in this special issue discuss both basic research in epigenetics as well as its potential applications in product safety assessment, be it a drug, environmental chemical or food additive. The reader will find several take-home conclusions including plenty of hope regarding the future of epigenetics in benefiting both the basic and the clinical sciences.
Supratim Choudhuri, PhD.
Guest Editor: Special Issue on Epigenetics and Toxicology
U.S. Food and Drug Administration,
Center for Food Safety and Applied Nutrition,
OFAS/DBGNR, HFS- 255,
5100 Paint Branch Parkway,
College Park, MD 20740, USA.
Tel: 301-436-1286; Fax: 301-436-2965.
E-mail: [email protected]