Randy L. Jirtle, Ph.D.

Radiation Epigenetics

Bernal, et. al. FASEB (Nov 2012)

These findings provide the first evidence that epigenetic alterations resulting from low-dose ionizing radiation (LDIR) play a role in radiation hormesis, bringing into question the assumption that every dose of radiation is harmful. Humans are exposed to LDIR from a number of environmental and medical sources. In this study, we show that LDIR significantly increases DNA methylation at the viable yellow agouti (Avy) locus in a dose- and sex-dependent manner. Moreover, maternal dietary antioxidant supplementation mitigated both the DNA methylation changes and coat color shift in the irradiated offspring. Thus, LDIR exposure during gestation elicits epigenetic alterations that lead to positive adaptive phenotypic changes that are negated with antioxidants, indicating they are mediated in part by oxidative stress.

January 19, 2013Tweet

NIH Wednesday Afternoon Lecture Series

On April 18, 2012, Dr. Jirtle delivered a lecture on "Epigenetics: How Genes and Environment Interact" as part of the NIH Director's prestigious Wednesday Afternoon Lecture Series.

August 9, 2012Tweet

Invitation by the Nobel Assembly

Dr. Jirtle was invited to speak by the Nobel Assembly at their 2011 meeting on Pharmacogenomics and Epigenomics in Clinical Medicine. His lecture was entitled "Environmental Epigenomics and the Developmental Origins of Adult Disease."

August 9, 2012Tweet

Person of the Year 2007 Nominee

Nora Volkow, Director of the National Institute on Drug Abuse and pioneer in the science of addiction, nominated Dr. Jirtle to be Time Magazine's Person of the Year 2007.

I'd select the Duke University scientist whose pioneering work in epigenetics and genomic imprinting has uncovered a vast territory in which a gene represents less of an inexorable sentence and more of an access point for the environment to modify the genome. The trailblazing discoveries of Dr. Randy Jirtle have produced a far more complete and useful understanding of human development and diseases.

August 9, 2012Tweet

Genome-wide mapping of human imprinted genes

Luedi, et. al. Genome Res. (Dec 2007)

Imprinted genes are at high risk for envolvement in diseases since a single genetic mutation or an environmentally-induced epigenetic change can alter their function. A genome-wide search for imprinted genes in the human genome, with the use of computer-learning algorithms, resulted in the identification of 156 novel candidate imprinted genes, fewer than the number predicted in mice and in many cases different. Consequently, mice may not be a suitable choice for studying diseases resulting principally from the epigenetic deregulation of imprinted genes, or for assessing human risk from environmental factors that alter the epigenome.

August 9, 2012Tweet

Negative bisphenol A effects on the epigenome blocked by nutritional supplements

Dolinoy, et. al. Proc. Natl. Acad. Sci. USA 104:13056-13061 (2007)

In utero or neonatal exposure to bisphenol A (BPA), a high-production-volume chemical used in the manufacture of polycarbonate plastic, is associated with higher body weight, increased breast and prostate cancer, and altered reproductive function. This study shows that exposure to BPA during pregnancy changes offspring phenotype by stably altering the epigenome, an effect that can be counteracted by maternal dietary supplements.

August 9, 2012Tweet

2006 Distinguished Achievement Award

University of Wisconsin-Madison, College of Engineering

Dr. Jirtle received the Distinguished Achievement Award from the University of Wisconsin-Madison College of Engineering at the 59th annual Engineers' Day.

Dr. Jirtle happily straddles the fields of biology and physics, and once again is using his engineering training as he begins a project to understand the impact of radiation on the epigenome. His efforts may enable him to identify nutritional supplements that protect the body from low-dose radiation.

August 9, 2012Tweet

Genistein methylates the fetal epigenome

Dolinoy, et. al. Environ Health Perspect 114:567-72 (2006)

Maternal dietary genistein supplementation of mice during gestation was shown in this paper to shift the coat color of Avy offspring from yellow to pseudoagouti by altering the epigenome rather than mutating the genome; a clear example of nature via nurture. Genistein, the major phytoestrogen in soy, is linked to diminished female reproductive performance and to cancer chemoprevention and decreased adipose deposition. Dietary genistein may also play a role in the decreased incidence of cancer in Asians compared with Westerners, as well as increased cancer incidence in Asians immigrating to the United States.

August 9, 2012Tweet

Genome-wide prediction of imprinted murine genes

Luedi, et. al. Genome Res 15:875-84 (2005)

A machine learning approach was used to both identify imprinted gene candidates and predict their parental expression preference across the entire mouse genome. This subset of genes is particularly important medically becasue imprinted genes could function as targets for linking environmental exposures during pregnancy to the susceptibility of developing chronic disorders as adults. Among those predicted to be imprinted are strong candidate genes for complex human conditions where parent-of-origin inheritance is involved, including Alzheimer disease, autism, bipolar disorder, diabetes, male sexual orientation, obesity, and schizophrenia.

August 9, 2012Tweet

Nobel symposium lecture

Dr Jirtle was invited to speak at the Nobel Symposium on Epigenetic Reprogramming in Development and Disease, held June 19-21, 2004 in Stockholm. He spoke on the “Biological Consequences of the Divergent Evolution of M6P/IGF2R Imprinting".

August 9, 2012Tweet