Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Short DNA strands in the genome may be key to understanding human cognition and diseases

22.11.2012
Previously discarded, human-specific 'junk' DNA represents untapped resource in the study of diseases like Alzheimer's and autism

Short snippets of DNA found in human brain tissue provide new insight into human cognitive function and risk for developing certain neurological diseases, according to researchers from the Departments of Psychiatry and Neuroscience at Mount Sinai School of Medicine. The findings are published in the November 20th issue of PLoS Biology.

There are nearly 40 million positions in the human genome with DNA sequences that are different than those in non-human primates, making the task of learning which are important and which are inconsequential a challenge for scientists. Rather than comparing these sequences strand by strand, Schahram Akbarian, MD, PhD, Professor of Psychiatry and Neuroscience at Mount Sinai School of Medicine, wanted to identify the crucial set of differences between the two genomes by looking more broadly at the chromatin, the structure that packages the DNA and controls how it is expressed.

They found hundreds of regions throughout the human genome which showed a markedly different chromatin structure in neurons in the prefrontal cortex, a brain region that controls complex emotional and cognitive behavior, compared to non-human primates. The findings of the study provide important insights for diseases that are unique to humans such as Alzheimer's disease and autism.

"While mapping the human genome has taught us a great deal about human biology, the emerging field of epigenomics may help us identify previously overlooked or discarded sequences that are key to understanding disease," said Dr. Akbarian. "We identified hundreds of loci that represent untapped areas of study that may have therapeutic potential."

Dr. Akbarian and his research team isolated small snippets of chromatin fibers from the prefrontal cortex. Next, they analyzed these snippets to determine what genetic signals they were expressing. Many of the sequences with human-specific epigenetic characteristics were, until recently, considered to be "junk DNA" with no particular function.

Now, they present new leads on how the human brain has evolved, and a starting point for studying neurological diseases. For example, the sequence of DPP10—a gene critically important for normal human brain development—not only showed distinct human-specific chromatin structures different from other primate brains such as the chimpanzee or the macaque, but the underlying DNA sequence showed some interesting differences from two extinct primates—the Neanderthal and Denisovan, most closely related to our own species and also referred to as 'archaic hominins'.

"Many neurological disorders are unique to human and are very hard as a clinical syndrome to study in animals, such as Alzheimer's disease, autism, and depression," said Dr. Akbarian. "By studying epigenetics we can learn more about those unique pieces of the human genome."

The research team also discovered that several of these chromatin regions appear to physically interact with each other inside the cell nucleus, despite being separated by hundreds of thousands of DNA strands on the genome. This phenomenon of "chromatin looping" appears to control the expression of neighboring genes, including several with a critical role for human brain development.

"There is growing consensus among genome researchers that much of what was previously considered as 'junk sequences' in our genomes indeed could play some sort of regulatory role," said Dr. Akbarian.

This study was supported by grants from the National Institutes of Health. Dr. Akbarian plans to do more epigenetic studies in other areas of the brain to see if there are additional chromatin regions that are unique to humans. They also plan to study the epigenomes of other mammals with highly evolved social behaviors such as elephants.

Dr. Akbarian joined Mount Sinai in July 2012. He is internationally known for his cutting-edge research on the epigenetic mechanisms of psychiatric disorders. He is a widely recognized expert in advanced chromatin tools—many of which were developed in his laboratory—in conjunction with mouse mutagenesis and behavioral models of mental illness to bridge molecular, cellular, and behavioral investigations. He is also a renowned authority on the epigenetic analysis of human brain tissue examined postmortem.

Prior to joining Mount Sinai, Dr. Akbarian was Director of the Brudnick Neuropsychiatric Research Institute. He received his medical and doctorate degrees from the Freie Universitaet Berlin. Dr. Akbarian completed his postdoctoral training in neuroscience at the University of California at Irvine and the Whitehead Institute, and his residency in psychiatry at Massachusetts General Hospital.


About The Mount Sinai Medical Center
The Mount Sinai Medical Center encompasses both The Mount Sinai Hospital and Mount Sinai School of Medicine. Established in 1968, Mount Sinai School of Medicine is one of the leading medical schools in the United States. The Medical School is noted for innovation in education, biomedical research, clinical care delivery, and local and global community service. It has more than 3,400 faculty in 32 departments and 14 research institutes, and ranks among the top 20 medical schools both in National Institutes of Health (NIH) funding and by US News and World Report.

The Mount Sinai Hospital, founded in 1852, is a 1,171-bed tertiary- and quaternary-care teaching facility and one of the nation's oldest, largest and most-respected voluntary hospitals. In 2011, US News and World Report ranked The Mount Sinai Hospital 14th on its elite Honor Roll of the nation's top hospitals based on reputation, safety, and other patient-care factors. Mount Sinai is one of 12 integrated academic medical centers whose medical school ranks among the top 20 in NIH funding and US News and World Report and whose hospital is on the US News and World Report Honor Roll. Nearly 60,000 people were treated at Mount Sinai as inpatients last year, and approximately 560,000 outpatient visits took place.

Mount Sinai Press Office | EurekAlert!
Further information:
http://www.mssm.edu
http://www.mountsinai.org/

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

Topologische Quantenchemie

21.07.2017 | Life Sciences

Pulses of electrons manipulate nanomagnets and store information

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>