Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New insights into how genes turn on and off

28.03.2013
Findings could enhance our understanding of human development, cancer therapies and autism

Researchers at UC Davis and the University of British Columbia have shed new light on methylation, a critical process that helps control how genes are expressed. Working with placentas, the team discovered that 37 percent of the placental genome has regions of lower methylation, called partially methylated domains (PMDs), in which gene expression is turned off. This differs from most human tissues, in which 70 percent of the genome is highly methylated.

While PMDs have been identified in cell lines, this is the first time they have been found in regular human tissue. In addition to enhancing our understanding of epigenetics, this work could influence cancer research and help illuminate how environmental toxins affect fetal development. The paper was published online this week in the Proceedings of the National Academy of Sciences (PNAS).

Since it was unraveled more than ten years ago, the human genome has been the focus of both popular interest and intense scientific focus. But the genome doesn't act alone; there are many factors that influence whether genes are turned on or off. One of these is an epigenetic process called methylation, in which a group of carbon and hydrogen atoms (a methyl group) attaches to DNA, adjusting how genes are expressed.

"I like to think of epigenetics as a layer on top of your genetic code," said senior author Janine LaSalle, professor of medical microbiology and immunology. "It's not the DNA sequence but it layers on top of that — and methylation is the first layer. Those layers provide a lot of information to the cells on where and when to turn on the genes."

How and when genes are activated (or inactivated) can have a profound impact on human development, cancer and the biological legacy of environmental toxins. Prior to this research, PMDs had only been found in cultured cell lines, which led some scientists to wonder if they existed outside the test tube. This study confirms they exist in placental tissue, a critically important window into fetal development.

"The placenta is the interface between mother and fetus," said LaSalle, who is a researcher affiliated with the UC Davis MIND Institute. "It's a time capsule from when a lot of important methylation events occurred."

In addition, placental tissue was interesting to study because it has a number of invasive characteristics often associated with cancer. In fact, a number of cancers, such as breast and colon, have widespread PMDs. LaSalle notes that anti-cancer epigenetic therapies that adjust methylation could be refined based on this improved understanding of PMDs.

This work could also enhance our ability to detect genetic defects. Methylation, and other epigenetic data, provides information that cannot be found in the genome alone. For example, the vast majority of cells in the body contain identical genetic code. However, the added information provided by methylation allows scientists to determine where specific DNA came from.

"Methylation patterns are like fingerprints, showing which tissue that DNA is derived from," LaSalle said. "You can't get that information from just the DNA sequence. As a result, methylation studies could be a very rich source for biomarkers."

In the study, PMDs encompassed 37 percent of the placental genome, including 3,815 genes, around 17 percent of all genes. When found in low-methylation regions, these genes were less likely to be transcribed into proteins. Researchers also found that PMDs also contain more highly methylated CpG islands (genomic areas with large numbers of cytosine-guanine pairs), which are often associated with gene transcriptional silencing of promoters.

Because the placental PMDs contained many genes associated with neuronal development, and specifically autism, LaSalle notes that future research could investigate how epigenetics impacts autism genes at birth.

"We are looking for biomarkers that predict neurodevelopmental outcomes," LaSalle said. "Now we have a series of snap shots from a critical period where we think environmental factors are playing a role in the developing brain."

The study's other authors include: Diane I. Schroeder, John Blair, Paul Lott, Hung On Ken Yu, Danna Hong, Florence Crary, Paul Ashwood, Cheryl Walker, Ian Korf and Wendy P. Robinson.

At the UC Davis MIND Institute, world-renowned scientists engage in collaborative, interdisciplinary research to find the causes of and develop treatments and cures for autism, attention-deficit/hyperactivity disorder (ADHD), fragile X syndrome, 22q11.2 deletion syndrome, Down syndrome and other neurodevelopmental disorders. For more information, visit http://mindinstitute.ucdavis.edu.

Phyllis Brown | EurekAlert!
Further information:
http://www.ucdmc.ucdavis.edu

More articles from Life Sciences:

nachricht Embryonic development: How do limbs develop from cells?
18.05.2018 | Humboldt-Universität zu Berlin

nachricht Reading histone modifications, an oncoprotein is modified in return
18.05.2018 | American Society for Biochemistry and Molecular Biology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>