Nav: Home

Genomic imprinting gets complicated in adults

October 03, 2016

While two copies of genes--one from each parent--is usually a good thing, for about a hundred genes, one copy--either the mother's or the father's copy--is silenced, a process known as genomic imprinting. This silencing was thought to be stable. But this silence doesn't last in certain cell types, finds a mouse study published September 20 in Cell Reports.

Whitehead Institute researchers made the discovery by using new technology that monitors changes in epigenetic marks on DNA over time (doi: 10.1016/j.cell.2015.08.046). With this resource, the researchers looked at a specific imprinted methylation mark (IG-DMR) in mouse embryonic stem cells that, if not in place on either the maternal or paternal copy of DNA, causes early embryonic death. As mice grew into adulthood, the investigators noticed that the imprinted methylation marks started to vary from cell to cell and that this variation differed depending on the cell type (e.g., retina cells kept much of the genomic imprinting while intestinal cells did not).

The study's findings indicate that these epigenetic marks can be regulated in adult tissues and challenge the hypothesis that genomic imprinting is maintained over time. Based on the analysis, it does appear that silencing one set of parental genes is essential during development, but afterwards, the silencing begins to vary by cell and cell type. In cells where the epigenetic marks are lost, the genes from the silenced parental DNA either cause overexpression or non-expression of those genes.

"There seems to be a requirement for more fine-tuned gene expression of imprinting in different tissues throughout development and in adulthood, which is a very exciting idea," says first author Yonatan Stelzer, a postdoctoral fellow in the lab of senior author Rudolf Jaenisch, of the Whitehead Institute for Biomedical Research and MIT.

The researchers plan to investigate why there could be cell type differences in genomic imprinting over time, whether there are any functional consequences of changes in imprinting, and whether environmental factors play a role in regulating these changes.

"It's essentially the first time that we can see epigenetic changes during development in vivo, this opens up a lot of questions because DNA methylation plays a role in key processes that we did not have a readout for," Stelzer says. "Now we can start applying unbiased screens of small molecules to affect this epigenetic phenomenon and ask basic questions on the role of DNA methylation changes in early development and disease."
-end-
This study was supported by the National Institutes of Health, a Human Frontier Postdoctoral Fellowship, and a NARSAD Young Investigator Fellowship. Rudolf Jaenisch is an advisor to Stemgent and a co-founder of Fate Therapeutics and Fulcrum Therapeutics.

Cell Reports, Stelzer et al.: "Parent-of-origin DNA methylation dynamics during mouse development" http://www.cell.com/cell-reports/fulltext/S2211-1247(16)31147-0

Cell Reports (@CellReports), published by Cell Press, is a weekly open-access journal that publishes high-quality papers across the entire life sciences spectrum. The journal features reports, articles, and resources that provide new biological insights, are thought-provoking, and/or are examples of cutting-edge research. Visit: http://www.cell.com/cell-reports. To receive Cell Press media alerts, contact press@cell.com.

Cell Press

Related Dna Articles:

Scientists now know what DNA's chaperone looks like
Researchers have discovered the structure of the FACT protein -- a mysterious protein central to the functioning of DNA.
In one direction or the other: That is how DNA is unwound
DNA is like a book, it needs to be opened to be read.
DNA is like everything else: it's not what you have, but how you use it
A new paradigm for reading out genetic information in DNA is described by Dr.
A new spin on DNA
For decades, researchers have chased ways to study biological machines.
From face to DNA: New method aims to improve match between DNA sample and face database
Predicting what someone's face looks like based on a DNA sample remains a hard nut to crack for science.
Self-healing DNA nanostructures
DNA assembled into nanostructures such as tubes and origami-inspired shapes could someday find applications ranging from DNA computers to nanomedicine.
DNA design that anyone can do
Researchers at MIT and Arizona State University have designed a computer program that allows users to translate any free-form drawing into a two-dimensional, nanoscale structure made of DNA.
DNA find
A Queensland University of Technology-led collaboration with University of Adelaide reveals that Australia's pint-sized banded hare-wallaby is the closest living relative of the giant short-faced kangaroos which roamed the continent for millions of years, but died out about 40,000 years ago.
DNA structure impacts rate and accuracy of DNA synthesis
DNA sequences with the potential to form unusual conformations, which are frequently associated with cancer and neurological diseases, can in fact slow down or speed up the DNA synthesis process and cause more or fewer sequencing errors.
Changes in mitochondrial DNA control how nuclear DNA mutations are expressed in cardiomyopathy
Differences in the DNA within the mitochondria, the energy-producing structures within cells, can determine the severity and progression of heart disease caused by a nuclear DNA mutation.
More Dna News and Dna Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

In & Out Of Love
We think of love as a mysterious, unknowable force. Something that happens to us. But what if we could control it? This hour, TED speakers on whether we can decide to fall in — and out of — love. Guests include writer Mandy Len Catron, biological anthropologist Helen Fisher, musician Dessa, One Love CEO Katie Hood, and psychologist Guy Winch.
Now Playing: Science for the People

#542 Climate Doomsday
Have you heard? Climate change. We did it. And it's bad. It's going to be worse. We are already suffering the effects of it in many ways. How should we TALK about the dangers we are facing, though? Should we get people good and scared? Or give them hope? Or both? Host Bethany Brookshire talks with David Wallace-Wells and Sheril Kirschenbaum to find out. This episode is hosted by Bethany Brookshire, science writer from Science News. Related links: Why Climate Disasters Might Not Boost Public Engagement on Climate Change on The New York Times by Andrew Revkin The other kind...
Now Playing: Radiolab

An Announcement from Radiolab