Epigenetics and Exercise

Turning on some genes
Turning on some genes

If, like me, you sometimes need more motivation to exercise consistently—even though you know that it is good for you—you may be interested in the findings of a paper published recently in PLOS Genetics. The paper showed that consistent exercise over a 6-month period caused potentially beneficial changes in gene expression. In short, regular exercise caused expression of some “good” genes, and repression of “bad” ones, and these changes appeared to be controlled by epigenetic mechanisms.

Epigenetic changes are modifications to DNA that affect gene expression but don’t alter the underlying sequence. Perhaps the best understood example of an epigenetic change is DNA methylation—where methyl groups bind to the DNA at specific sites and alter expression, often by preventing transcription. Epigenetic changes have been shown to occur throughout all stages of development and in response to environmental factors such as diet, toxin exposure, or stress. The study of epigenetics is revealing more and more about how the information stored in our DNA is expressed in different tissues at different times and under different environmental circumstances. Continue reading “Epigenetics and Exercise”

A New Edge in Bisulfite Conversion

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Aberrant methylation events have significant impacts in terms of incidence of cancer and development disregulation. Researchers studying DNA methylation are often working with DNA from “difficult” tissues such as formalin-fixed, paraffin embedded tissues, which characteristically yield DNA that is more fragmented than that purified from fresh tissue. Traditional methods for bisulfite conversion involve a long protocol, harsh chemicals, and generally yield highly fragmented DNA. The DNA fragmentation may significantly impact the utility of the converted DNA in downstream applications such as bisulfite-specific PCR or bisulfite sequencing.

An ideal bisulfite conversion system enables complete conversion of a DNA sample in a short period of time, provides high yield of DNA, minimally fragments the DNA, works on a wide range of input DNA amounts (from a wide variety of sample types), and, while we’re at it, is easy to use and to store. Whew! That’s quite the list.

Continue reading “A New Edge in Bisulfite Conversion”

Hypomethylation in the Hippocampus: Can Age-Related Cognitive Decline in Mice Be Reversed by the Activity of One Gene?

Partial ribbon structure of DNMT3a Source: Protein Database
Buried in the middle of the August issue of Nature Neuroscience is an article (1) by Oliveira, Hemstedt and Bading that caught my eye. It isn’t often that I see a paper about gene rescue in a neuroscience journal, especially in a study about cognitive decline.

I looked for a News and Views summary of the article, thinking that if the conclusions of the article were anything like what the title and abstract indicated, there must be an editorial summary. I wasn’t disappointed. Su and Tsai provided a nice summary of the paper and discussed some of the potential implications of the work (2). Continue reading “Hypomethylation in the Hippocampus: Can Age-Related Cognitive Decline in Mice Be Reversed by the Activity of One Gene?”

Bisulfite Conversion and Next Gen Sequencing

WebinarsIn my last entry, I gave a little summary of one of many techniques that are used to study DNA methylation patterns in a loci-specific fashion using the COBRA technique. This time, we’ll take a look at a high-throughput, genome-wide method for analyzing DNA methylation status using a next generation sequencing approache called bisulfite sequencing, or Bis-Seq. Continue reading “Bisulfite Conversion and Next Gen Sequencing”

The Link Between Childhood Adversity and Cellular Aging

Neglected childAdversity and stress are known risk factors for psychiatric disorders, cardiovascular and immune disease, cognitive decline and other health problems. The long-term negative effects of adversity seem to be greatest if the traumatic events were experienced during childhood, when the brain and other biological systems are developing and maturing. Researchers are working to identify the mechanisms involved and have identified telomere shortening as one possible mechanism by which adversity increases morbidity and mortality. Continue reading “The Link Between Childhood Adversity and Cellular Aging”