Corporate Banner
Satellite Banner
Biomolecular Screening
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Short DNA Strands in the Genome May be Key to Understanding Human Cognition and Diseases

Published: Monday, November 26, 2012
Last Updated: Monday, November 26, 2012
Bookmark and Share
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.


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,400+ scientific posters on ePosters
  • More than 3,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.


Scientific News
New Tool Uses 'Drug Spillover' to Match Cancer Patients with Treatments
Researchers have developed a new tool that improves the ability to match drugs to disease: the Kinase Addiction Ranker (KAR) predicts what genetics are truly driving the cancer in any population of cells and chooses the best "kinase inhibitor" to silence these dangerous genetic causes of disease.
HIV Susceptibility Linked to Little-Understood Immune Cell Class
High levels of diversity among immune cells called natural killer cells may strongly predispose people to infection by HIV, and may be driven by prior viral exposures, according to a new study.
Sweet Revenge Against Superbugs
A special type of synthetic sugar could be the latest weapon in the fight against superbugs.
Access Denied: Leukemia Thwarted by Cutting Off Link to Environmental Support
A new study reveals a protein’s critical – and previously unknown -- role in the development and progression of acute myeloid leukemia (AML), a fast-growing and extremely difficult-to-treat blood cancer.
Long-sought Discovery Fills in Missing Details of Cell 'Switchboard'
A biomedical breakthrough reveals never-before-seen details of the human body’s cellular switchboard that regulates sensory and hormonal responses.
Tracking Breast Cancer Before it Grows
A team of scientists led by University of Saskatchewan researcher Saroj Kumar is using cutting-edge Canadian Light Source techniques to screen and treat breast cancer at its earliest changes.
Zebrafish Reveal Drugs that may Improve Bone Marrow Transplant
Compounds boost stem cell engraftment; could allow more matches for patients with cancer and blood diseases.
DNA Damage Seen in Patients Undergoing CT Scanning
Along with the burgeoning use of advanced medical imaging tests over the past decade have come rising public health concerns about possible links between low-dose radiation and cancer.
The Light of Fireflies for Medical Diagnostics
EPFL scientists have exploited the light of fireflies in a new method that detects biological molecules without the need for complex devices and high costs.
Vital Protein in Healthy Fertilization Process Identified
Researchers at the National Institutes of Health have discovered a protein that plays a vital role in healthy egg-sperm union in mice.
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,400+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!