08 Jul Epigenetics Key To Understanding Interplay Between Nature and Nuture

MedicalResearch.com Interview with:

Dr. Michelle Holland

Dr. Michelle L. Holland
The Blizard Institute, Barts and The London School of Medicine and Dentistry
Queen Mary University of London
London

MedicalResearch.com: What is the background for this study?

Response: There is strong evidence that the early life environment can influence lifelong health-a phenomenon termed ‘developmental programming.’ However, the mechanisms by which this occurs are poorly understood.

Here, we set out to explore whether epigenetic marks-modifications to DNA that influence whether a gene is ‘on’ or ‘off,’ are altered in response to the early life environment and whether this relates to later life health.

MedicalResearch.com: What are the main findings?

Response: We fed pregnant mice a protein restricted diet, containing about half the protein content of standard feed. As may be expected, the offspring of these mothers were smaller at weaning and also showed other metabolic differences in adulthood. We initially scanned the genome to see whether we could detect perturbations of DNA methylation-an epigenetic mark in these offspring. Surprisingly, we only saw a disturbance at a region of the genome that is not included in genome assemblies (i.e. maps). This part of the genome, called rDNA, encodes the RNA components of ribosomes-cellular machines involved in protein production. rDNA exists in hundreds of copies and even in a genetically controlled mouse strain, we found that these copies vary with regards to their genetic sequence. Furthermore, only specific genetic variants appear to alter DNA methylation in response to maternal protein restriction and the number of copies of this variant within the genome of an individual animal correlated not only with the amount of DNA methylation but also the amount of growth restriction induced by the diet.

MedicalResearch.com: What should readers take away from your report?

Response: The key message from this work is that this is an example of underlying genetic diversity driving a physiological outcome only after a particular environmental exposure. That is, nature and nurture are not distinguishable and interact in complex ways to determine an individual’s characteristics.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Response: It would be very interesting to see how much genetic diversity exists at rDNA in humans and whether such environmental interactions are occurring. Furthermore, our work and that of others suggests that regulation of protein production may be a key response to environmental stresses that may lead to persistent outcomes after the exposure has ceased.

MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.

Citation:

Vardhman Rakyan et al. Early-life nutrition modulates the epigenetic state of specific rDNA genetic variants in mice. Science, July 2016 DOI: 10.1126/science.aaf7040

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Last Updated on July 8, 2016 by Marie Benz MD FAAD