Typical news headline with an article full of misunderstanding. An individual's DNA doesn't change, it's the profile of gene expression that does. It doesn't seem surprising that gene expression of certain cells would change in response to different seasons (it's fairly obvious that our bodies react and adapt to different environmental conditions) but the study is interesting for gathering data on this phenomenon, particularly with regard to immunology. That last bit could have important implications for seasonal healthcare provision.
Widespread seasonal gene expression reveals annual differences in human immunity and physiology
Dopico et al (2015)
Yes, the paper does not examine the individuals' DNA at all, just the amount of mRNA produced from the DNA. These changes in could be caused by changes in the DNA, but these changes are not due to changes to the sequence of the DNA, but to certain chemical tags (methyl groups) that get added to the DNA. These chemical tags that get added to the DNA and to the histone proteins that package the DNA in the nucleus help determine which DNA sequences are available and able to be expressed, and which DNA sequences are unavailable to be expressed. It would be an interesting follow up study to see if location of these chemical tags change with the seasons as well.
I wonder what this suggests for research on these tissues. Will experiments done during the summer give different results than experiments done in the winter?
This reminds me of sirt3, associated with human longevity:
Which gets upregulated during exposure to cold temperatures (and appetite restriction)
It's worth noting that there is some controversy surrounding whether the sirtuin genes are involved in aging and longevity (see these news articles from Science and Nature or this nice summary from the http://pipeline.corante.com/archives/2011/09/22/the_latest_sirtuin_controversy.php[/URL] blog).
It has long been observed that metabolism changes with seasons. The O-glcnac modification directly descends from glucose metabolism and is involved in writing almost every aspect of your epigenetic code, many other important gene regulatory processes, and internal clocks:
O-glcnac is invovled in the histone code:
O-glcnac is inovled in regulating DNA methylation:
O-glcnac is also involved with the protein complex that regulates histone acetylation:
O-glcnac regulates the circadian rythm:
O-glcnac regulates RNA poly II transcription and a whole bunch of transcription factors have their activity regulated by sugar metabolism:
Too many journal articles to read, but the main point is that many animals alter their metabolism during a period of hibernation. Even humans have documented changes in metabolism due to seasonal changes. Metabolism is essentially an extraordinary biosensor that links the environment, space, and time and digests that information to regulate the metabolic fluxes that produce the concentrations of UDP-GlcNAc--the metabolite responsible for the O-GlcNAc modification. If you were to permeabilize a cell to let in certain types of lectins (proteins that bind to sugar), you'd surprisingly find that chromatin for some reason is absolutely covered in sugar. We now recognize that almost every type of machinery involved in genetic transcription, epigenetic modifications, and even almost all of the proteins involved in higher order chromatin structure are in some way regulated by O-GlcNAc (which is why you find chromatin covered in sugar with lectins). O-GlcNAc is the link between environment/stress/and nutrition and epigenetics/genetic expression.
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