Adaptation and Changing Phenotypes through Transgenerational Epigenetics
The field of epigenetics is ripe with exciting new discoveries that have far reaching implications for adaptation and changing phenotypes, particularly in the area of transgenerational epigenetics, defined as non-DNA sequence-based alterations that can be transmitted from one generation to the next. Different from inter-generational or parental effects, such as in utero exposure to chemicals that impact germ line cells in the developing embryo, transgenerational epigenetic inheritance refers to DNA CpG dinucleotide methylations and biochemical changes in DNA associated histone proteins that persist, even in the absence of initial causes that led to the changes, such as environmental exposure. This type of phenomenon may have evolved to allow organisms to adapt to environmental conditions and transmit information critical for survival under extreme conditions to subsequent generations. Research shows that these non-DNA sequence-based epigenetic marks can be inherited across several generations in organisms ranging from plants to single celled eukaryotes, mice, rats, and even humans. The repertoire of epigenetic signals found to be transgenerational include histone modifications as well as DNA methylations. Environmental factors known to induce transgenerational epigenetic changes include hypoxic conditions, temperature variability, nutrition, sunlight, toxins, radiation, osmotic stress in plants, and odorants. Evidence also exists for social and behavioral variables impacting transgenerational epigenetic inheritance patterns including maternal nurturing, trauma, activity levels or exercise, and predator-prey interactions. Epigenetic marks, notably DNA methylations, are responsible for gene imprinting, which silences alleles based on their maternal or paternal origin. Importantly, the imprints are reprogrammed during spermatogenesis and oogenesis. How the reprogramming is achieved and why other epigenic marks escape it, allowing the epigenomic landscape to be inherited is not fully understood. This Article Collection contains articles, reviews, and brief reports documenting evidence of these phenomena in humans as well as other organisms, especially studies delineating potential molecular mechanisms regulating transmission and reprogramming of epigenetic information.
Edited by
Lon J. Van Winkle PhD(Rocky Vista University/Midwestern University)
Dr Van Winkleis a Professor of Medical Humanities at Rocky Vista University. His work has been supported by grants from the Illinois Board of Higher Education, the Illinois Regenerative Medicine Institute, and the National Institutes of Health publishing over 100 peer reviewed publications and five books concerning biomembrane transport, embryo development, stem cells, emerging talents in pharmacology, and interprofessional education.
Philip M. Iannaccone MD, PhD(Northwestern University (NU))
Dr Iannaccone served as the Chairman of the Board of Scientific Counselors of the National Institute of Environmental Health. He served as the Director of the Developmental Biology Program of the Stanley Manne Children’s Research Institute, the Deputy Director and Senior Vice President of the Institute, the Director of the Northwestern University MD/Ph.D. and NU’s Markey Program in Developmental Biology.
Rebecca J. Ryznar PhD(Rocky Vista University)
Dr. Ryznar is currently an Associate Professor of Molecular Biology at Rocky Vista University. Her research interests include stress response and regulation, psychoneuroimmunology axis, transgenerational epigenetics, and trauma.