(Press-News.org) Despite progress in decoding the genome, scientists estimate that fully 95 percent of our DNA represents dark, unknown territory. In the October 1 issue of the journal Cell researchers at The Wistar Institute shed new light on the genetic unknown with the discovery of the ability of long non-coding RNA (ncRNA) to promote gene expression. The researchers believe these long ncRNA molecules may represent so-called gene enhancer elements—short regions of DNA that can increase gene transcription. While scientists have known about gene enhancers for decades, there has been no consensus about how these enhancers work.
These findings join a growing body of evidence that the classic "central dogma" of genetics is incomplete. In the central dogma, chromosomal DNA is transcribed into RNA, which is then translated by the cell into proteins. In recent years, however, scientists have found that not all transcribed RNA molecules become translated into proteins. In fact, studies have shown that whole swathes of the genome are transcribed for unknown reasons.
In the present study, the Wistar researchers pinpoint 3,000 long ncRNAs and estimate that there could be a total of between 10,000 to 12,000 long ncRNA sequences within our DNA. This number is comparable to the 20,000 genes that are known to encode proteins. Most long ncRNAs are encoded in DNA near genes known to be important to both stem cells and cancer. This observation also suggests that targeting ncRNAs may represent a new strategy in slowing cancer growth.
"We are excited, first of all, because this is a new discovery about the very nature of human DNA; a new class of genetic object and a new layer of genetic regulation," said Ramin Shiekhattar, Ph.D., Wistar's Herbert Kean, M.D., Family Professor and senior author of the study.
"Secondly, we may have solved, in part, a great mystery in modern genetics. These long non-coding RNA sequences may account for the activity of enhancer elements, which have been well-studied but never quite characterized," Shiekhattar said.
Almost three years ago, while at the Centre for Genomic Regulation in Barcelona, Spain, Shiekhattar began a prospective hunt for non-coding RNA sequences using GENCODE, a database that annotates the human genome with currently available scientific evidence. After filtering out protein-coding transcripts and non-coding RNAs that might overlap known protein-coding genes, they found approximately 3,000 long ncRNA sequences. At the time, GENCODE only accounted for a third of the genome, so Shiekhattar estimates that there are likely more.
The researchers mapped the ncRNA sites within the genome, and found that ncRNAs tended to be located near genes that influence how stem cells change into other cell types. Shiekhattar and his colleagues then developed new assays to screen cell cultures for these ncRNA sequences, and discovered that ncRNAs were found extensively in a variety of cell types.
The idea that molecules of RNA can have a DNA-regulating effect is well established. More than 1,000 so-called microRNAs are known to science, for example, and their effect on silencing genes has been well described. According to Shiekhattar, he assumed that long ncRNAs would also silence genes, not promote their activation. To his surprise, the researchers found that depleting a cell of ncRNAs actually decreased the degree of overall gene expression of neighboring genes, revealing a role for ncRNAs in potentiating gene expression.
In fact, when Shiekhattar and his colleagues depleted adult stem cells of a specific long ncRNA, known as ncRNA-activating 7 (ncRNA-a7), it had the same effect as depleting the protein product of a nearby gene, Snai1, which regulates how the cells migrate. Their studies further showed that inserting an ncRNA next to a gene for luciferase—the enzyme responsible for a firefly's glow—increased the amount of protein produced by that gene in cells grown in culture. While not all long ncRNAs may act like enhancers, the majority of the ones the team studied do, Shiekhattar says.
"We know long non-coding RNAs can promote gene expression, but what we need to know now is how they do it," Shiekhattar said, "which is precisely the object of our ongoing research plan."
INFORMATION:
Wistar co-authors include Ulf Andersson Ørom, Ph.D., first author and postdoctoral fellow in the Shiekhattar laboratory; Qihong Huang, M.D., Ph.D., a Wistar professor; Kiranmai Gumireddy, Ph.D., a senior staff scientist in the Huang laboratory; Malte Beringer, Ph.D., Alessandro Gardini, Ph.D., and Fan Lai, Ph.D., postdoctoral fellows in the Shiekhattar laboratory. Co-authors from the Centre for Genomic Regulation include Thomas Derrien, Ph.D., Giovanni Bussotti, Ph.D., Matthias Zytnicki, Ph.D., Cedric Notredame, Ph.D., and Roderic Guigo, Ph.D.
Funding for this study was provided by the National Institutes of Health, the American Italian Cancer Foundation, and the Danish Council for Independent Research.
Wistar researchers discover new class of objects encoded within the genome
Long non-coding rna molecules function similar to gene enhancer elements
2010-10-07
ELSE PRESS RELEASES FROM THIS DATE:
UF study: Emotional effects of heavy combat can be lifelong for veterans
2010-10-07
GAINESVILLE, Fla. — The trauma from hard combat can devastate veterans until old age, even as it influences others to be wiser, gentler and more accepting in their twilight years, a new University of Florida study finds.
The findings are ominous with the exposure of today's men and women to heavy combat in the ongoing Iraq and Afghanistan wars on terror at a rate that probably exceeds the length of time for U.S. veterans during World War II, said UF sociologist Monika Ardelt.
"The study shows that we really need to take care of our veterans when they arrive home, because ...
New soy-based natural S-equol supplement reduces menopausal hot flashes, muscle and joint pain in first study among US women
2010-10-07
CHICAGO, IL (Oct. 6, 2010) – A new women’s health, whole soy germ-based nutritional supplement containing Natural S-equol reduced the frequency of moderate to severe hot flashes and reduced muscle and joint pain in the first study of its kind among postmenopausal U.S. women, according to peer-reviewed data presented as a poster presentation at the North American Menopause Society (NAMS) Annual Meeting. Also, the first study to report Natural S-equol contributions to bone health and a study of Natural S-equol safety were presented at NAMS.
“These data from U.S. women ...
Tip sheet: Soy-based natural S-equol supplement data presented from 4 studies at the North American Menopause Society Annual Meeting
2010-10-07
Four clinical studies that add to the evidence about the use of a new nutritional supplement containing the whole soy germ-based ingredient Natural S-equol to improve health were presented at the North American Menopause Society (NAMS) Annual Meeting. These studies include a poster about a first-of-its-kind study in U.S. women that documents the effectiveness of Natural S-equol in reducing the frequency of moderate to severe hot flashes and reducing muscle and joint pain. A second poster reported the first clinical study about Natural S-equol contributions to bone health. ...
Family ties bind desert lizards in social groups
2010-10-07
SANTA CRUZ, CA-- Researchers at the University of California, Santa Cruz, have found that a species of lizard in the Mojave Desert lives in family groups and shows patterns of social behavior more commonly associated with mammals and birds. Their investigation of the formation and stability of family groups in desert night lizards (Xantusia vigilis) provides new insights into the evolution of cooperative behavior.
The researchers reported the results of a five-year study of desert night lizards in a paper published in the Proceedings of the Royal Society B: Biological ...
GOES-13 on top of new seventeenth Atlantic (sub) tropical depression
2010-10-07
The GOES-13 satellite keeps a vigilant eye on the Atlantic Ocean and eastern U.S. and this morning at 5 a.m. EDT it saw System 97L organize into the seventeenth tropical depression of the Atlantic Ocean season. The only catch is that it is actually a subtropical depression, so it is currently known as Subtropical Depression 17 (TD17).
A subtropical storm is one where central convection (rapidly rising air that forms thunderstorms) is fairly near the center and it has a warming core in the mid-levels of the troposphere. Subtropical cyclones differ from tropical cyclones ...
Skin color linked to social inequality in contemporary Mexico, study shows
2010-10-07
WASHINGTON, DC, October 6, 2010 — Despite the popular, state-sponsored ideology that denies the existence of prejudice based on racial or skin color differences in Mexico, a new study from The University of Texas at Austin provides evidence of profound social inequality by skin color.
According to the study, individuals with darker skin tones have less education, have lower status jobs, are more likely to live in poverty, and are less likely to be affluent.
Andrés Villarreal, an associate professor in the Department of Sociology and the Population Research Center affiliate, ...
Swedish Research Council to bar cheaters
2010-10-07
Barred for up to ten years from receiving research grants from the Swedish Research Council. There will be serious consequences for the few researchers who are guilty of plagiarism, falsification, or inventing results.
"We need to be able to rely on research findings," says Pär Omling, Director General of the Swedish Research Council.
The Swedish Research Council has made a decision about how it should deal with researchers who are found to have committed research fraud. Any researcher who has been vetted by a panel of experts within the Central Ethical Review Board ...
Gene therapy reveals unexpected immunity to dystrophin in patients with Duchenne muscular dystrophy
2010-10-07
An immune reaction to dystrophin, the muscle protein that is defective in patients with Duchenne muscular dystrophy, may pose a new challenge to strengthening muscles of patients with this disease, suggests a new study appearing in the October 7, 2010, issue of The New England Journal of Medicine.
Duchenne muscular dystrophy (DMD) is a hereditary and lethal neuromuscular disease characterized by progressive loss of muscle strength and integrity. Genetic information important for production of a functional dystrophin protein is deleted from the DMD gene of many patients. ...
Drug that helps adults addicted to opioid drugs also relieves withdrawal symptoms in newborns
2010-10-07
(PHILADELPHIA) - Thousands of infants each year have exposure to opioids before they are born. Over half of these infants are born with withdrawal symptoms severe enough to require opioid replacement treatment in the nursery. Such treatment is associated with long hospital stays which interferes with maternal/infant bonding. Now, a team of researchers at Thomas Jefferson University has tested a semi-synthetic opioid they say has the potential to improve the treatment of these newborns, which could save hundreds of millions in healthcare costs annually if future tests continue ...
High risk of acute mountain sickness on Mount Kilimanjaro
2010-10-07
New Rochelle, NY, October 6, 2010 –Climbers of high peaks such as Mount Kilimanjaro are at high risk for Acute Mountain Sickness (AMS). Trekkers should not ignore AMS warning signs, which can progress to more serious medical outcomes. Mountain climbers can best minimize their risk for altitude sickness by becoming acclimatized to increased altitudes before an ascent, according to a study in the current issue of High Altitude Medicine & Biology, a peer-reviewed journal published by Mary Ann Liebert, Inc. (www.liebertpub.com). The article is available free online at www.liebertpub.com/ham
The ...
LAST 30 PRESS RELEASES:
H.E.S.S. collaboration detects the most energetic cosmic-ray electrons and positrons ever observed
Novel supernova observations grant astronomers a peek into the cosmic past
Association of severe maternal morbidity with subsequent birth
Herodotus' theory on Armenian origins debunked by first whole-genome study
Women who suffer pregnancy complications have fewer children
Home testing kits and coordinated outreach substantially improve colorectal cancer screening rates
COVID-19 vaccine reactogenicity among young children
Generalizability of clinical trials of novel weight loss medications to the US adult population
Wildfire smoke exposure and incident dementia
Health co-benefits of China's carbon neutrality policies highlighted in new review
Key brain circuit for female sexual rejection uncovered
Electrical nerve stimulation eases long COVID pain and fatigue
ASTRO issues update to clinical guideline on radiation therapy for rectal cancer
Mount Sinai opens the Hamilton and Amabel James Center for Artificial Intelligence and Human Health to transform health care by spearheading the AI revolution
Researchers develop tools to examine neighborhood economic effects on spinal cord injury outcomes
Case Western Reserve University awarded $1.5 million to study vaginal bacterial linked to serious health risks
The next evolution of AI begins with ours
Using sunlight to recycle black plastics
ODS FeCrAl alloys endure liquid metal flow at 600 °C resembling a fusion blanket environment
A genetic key to understanding mitochondrial DNA depletion syndrome
The future of edge AI: Dye-sensitized solar cell-based synaptic device
Bats’ amazing plan B for when they can’t hear
Common thyroid medicine linked to bone loss
Vaping causes immediate effects on vascular function
A new clock to structure sleep
Study reveals new way to unlock blood-brain barrier, potentially opening doors to treat brain and nerve diseases
Viking colonizers of Iceland and nearby Faroe Islands had very different origins, study finds
One in 20 people in Canada skip doses, don’t fill prescriptions because of cost
Wildlife monitoring technologies used to intimidate and spy on women, study finds
Around 450,000 children disadvantaged by lack of school support for color blindness
[Press-News.org] Wistar researchers discover new class of objects encoded within the genomeLong non-coding rna molecules function similar to gene enhancer elements