(Press-News.org) DALLAS – August 18, 2014 – Researchers at UT Southwestern Medical Center have found a new way that internal body clocks are regulated by a type of molecule known as long non-coding RNA.
The internal body clocks, called circadian clocks, regulate the daily "rhythms" of many bodily functions, from waking and sleeping to body temperature and hunger. They are largely "tuned" to a 24-hour cycle that is influenced by external cues such as light and temperature.
"Although we know that long non-coding RNAs are abundant in many organisms, what they do in the body, and how they do it, has not been clear so far," said Dr. Yi Liu, Professor of Physiology. "Our work establishes a role for long non-coding RNAs in 'tuning' the circadian clock, but also shows how they control gene expression."
Determining how circadian clocks work is crucial to understanding several human diseases, including sleep disorders and depression in which the clock malfunctions. The influence of a functional clock is evident in the reduced performance of shift workers and the jet lag felt by long-distance travellers.
Dr. Liu and his team were able to learn more about the circadian rhythms by studying model systems involving the bread mold, Neurospora crassa. The researchers found that the expression of a clock gene named frequency (frq) is controlled by a long non-coding RNA named qrf (frq backwards) − an RNA molecule that is complementary, or antisense, to frq. Unlike normal RNA molecules, qrf does not encode a protein, but it can control whether and how much frq protein is produced.
Specifically, qrf RNA is produced in response to light, and can then interfere with the production of the frq protein. In this way, qrf can "re-set" the circadian clock in a light-dependent way. This regulation works both ways: frq can also block the production of qrf. This mutual inhibition ensures that the frq and qrf RNA molecules are present in opposite "phases" of the clock and allows each RNA to oscillate robustly. Without qrf, normal circadian rhythms are not sustained, indicating that the long non-coding RNA is required for clock functions.
The findings are published online in the journal Nature.
"We anticipate a similar mode of action may operate in other organisms because similar RNAs have been found for clock genes in mice. In addition, such RNAs may also function in other biological processes because of their wide presence in genomes," said Dr. Liu, who is the Louise W. Kahn Scholar in Biomedical Research.
UT Southwestern investigators are leaders in unraveling the gene networks underlying circadian clocks and have shown that most body organs, such as the pancreas and liver, have their own internal clocks, and that virtually every cell in the human body contains a clock. It now appears that the clocks and clock-related genes – some 20 such genes have been identified – affect virtually all of the cells' metabolic pathways, from blood sugar regulation to cholesterol production.
Other UT Southwestern researchers involved in the latest findings include Dr. Zhihong Xue, Qiaohong Ye, Dr. Juchen Yang and Dr. Guanghua Xiao. Support for this research included grants from the National Institutes of Health, the Welch Foundation, the Cancer Prevention Research Institute of Texas, and the Biotechnology and Biological Sciences Research Council.
"This study adds to an important body of work that has shown the ubiquity of a circadian clock across species, including humans, and its role in metabolic regulation in cells, organs, and organisms," said Dr. Michael Sesma, Program Director in the Division of Genetics and Developmental Biology at the of the National Institutes of Health's National Institute of General Medical Sciences, which partially funded the research. "These new results from Dr. Liu and his colleagues also extend beyond understanding the function of an anti-sense RNA in the fine tuning of a cell's daily rhythm; they provide an example of the means by which anti-sense transcription likely regulates other key molecular and physiological processes in cells and organisms."
INFORMATION:
About UT Southwestern Medical Center
UT Southwestern, one of the premier academic medical centers in the nation, integrates pioneering biomedical research with exceptional clinical care and education. The institution's faculty includes many distinguished members, including six who have been awarded Nobel Prizes since 1985. Numbering more than 2,700, the faculty is responsible for groundbreaking medical advances and is committed to translating science-driven research quickly to new clinical treatments. UT Southwestern physicians provide medical care in 40 specialties to nearly 91,000 hospitalized patients and oversee more than 2 million outpatient visits a year.
Researchers obtain key insights into how the internal body clock is tuned
2014-08-18
ELSE PRESS RELEASES FROM THIS DATE:
UM research improves temperature modeling across mountainous landscapes
2014-08-18
MISSOULA – New research by University of Montana doctoral student Jared Oyler provides improved computer models for estimating temperature across mountainous landscapes.
The work was published Aug. 12 in the International Journal of Climatology in an article titled "Creating a topoclimatic daily air temperature dataset for the conterminous United States using homogenized station data and remotely sensed land skin temperature."
Collaborating with UM faculty co-authors Ashley Ballantyne, Kelsey Jencso, Michael Sweet and Steve Running, Oyler provided a new climate dataset ...
Passport study reveals vulnerability in photo-ID security checks
2014-08-18
Security systems based on photo identification could be significantly improved by selecting staff who have an aptitude for this very difficult visual task, a study of Australian passport officers suggests.
Previous research has shown that people find it challenging to match unfamiliar faces.
"Despite this, photo-ID is still widely used in security settings. Whenever we cross a border, apply for a passport or access secure premises, our appearance is checked against a photograph," says UNSW psychologist Dr David White.
To find out whether people who regularly carry out ...
New study reveals vulnerability in photo-ID security checks
2014-08-18
Passport issuing officers are no better at identifying if someone is holding a fake passport photo than the average person, new research has revealed.
A pioneering study of Australian passport office staff by a team of psychologists from Aberdeen, York and Sydney, revealed a 15% error rate in matching the person to the passport photo they were displaying.
In real life this degree of inaccuracy would correspond to the admittance of several thousand travellers bearing fake passports.
The findings are published today (Monday August 18) in the journal PLOS ONE.
They ...
Older coral species more hardy, UT Arlington biologists say
2014-08-18
New research indicates older species of coral have more of what it takes to survive a warming and increasingly polluted climate, according to biologists from the University of Texas at Arlington and the University of Puerto Rico – Mayagüez.
The researchers examined 140 samples of 14 species of Caribbean corals for a study published by the open-access journal PLOS ONE on Aug. 18.
Jorge H. Pinzón C., a postdoctoral researcher in the UT Arlington Department of Biology, is lead author on the study. Co-authors are Laura Mydlarz, UT Arlington associate professor of biology, ...
Tropical Storm Karina: status quo on infrared satellite imagery
2014-08-18
Since Tropical Storm Karina weakened from hurricane status, and since then, NASA satellite data has shown that the storm has been pretty consistent with strength and thunderstorm development.
Hurricane Karina formed on August 13, 2014 off the Mexican coast. The Tropical Rainfall Measuring Mission or TRMM satellite passed directly above the center of intensifying tropical storm Karina on August 14, 2014 at 1927 UTC (3:27 p.m. EDT). TRMM's Microwave Imager showed that storms near Karina's center were dropping rain at a rate of over 50mm (almost 2 inches) per hour. After ...
Surprising number of older adults weathered 'The Great Recession' without financial strain
2014-08-18
The "Great Recession" may have put a dent in many older adults' pocketbooks, but a new study by Baylor University found that more than 40 percent reported a decrease in "financial strain" between 2006 and 2010.
Researcher Lindsay R. Wilkinson, an assistant professor of sociology in Baylor University's College of Arts & Sciences, drew on 5,205 respondents from the Health and Retirement Study (HRS) to examine the effect of financial strain on the mental health and use of mood-altering drugs by older adults. HRS, sponsored by the National Institute on Aging, is the largest ...
12th tropical depression appears huge on satellite imagery
2014-08-18
The Eastern Pacific has generated the twelfth tropical depression of the hurricane season, and satellite imagery showed that it dwarfs nearby Tropical Storm Karina.
Tropical cyclones are usually a couple of hundred miles in diameter. The average size of a tropical cyclone is around 304 nautical miles (350 miles/600 km) in diameter. The National Hurricane Center noted on August 18 at 11 a.m. EDT that Tropical Depression 12-E was at least 800 nautical miles (920.6 miles/1,482 km) in diameter! By comparison, Tropical Storm Karina is a couple of hundred miles in diameter. ...
Zombie ant fungi manipulate hosts to die on the 'doorstep' of the colony
2014-08-18
A parasitic fungus that must kill its ant hosts outside their nest to reproduce and transmit their infection, manipulates its victims to die in the vicinity of the colony, ensuring a constant supply of potential new hosts, according to researchers at Penn State and colleagues at Brazil's Federal University of Vicosa.
Previous research shows that Ophiocordyceps camponoti-rufipedis, known as the "zombie ant fungus," controls the behavior of carpenter ant workers -- Camponotus rufipes -- to die with precision attached to leaves in the understory of tropical forests, ...
Why aren't pregnant women getting flu vaccine?
2014-08-18
Both mother and fetus are at increased risk for complications of flu infection during pregnancy. And prenatal care providers say they're advising women to get the flu vaccine, in line with recommendations from various organizations. But many pregnant women don't understand the importance of this advice—and don't get the vaccine.
Robert Arao, MPH, a biostatistician at Group Health Research Institute, did a statewide survey—the first of its kind—to assess what doctors think and do about flu vaccines for pregnant women. Mr. Arao was at the Oregon Health & Science University ...
Massachussetts General-developed device monitors key step in development of tumor metastases
2014-08-18
A microfluidic device developed at Massachusetts General Hospital (MGH) may help study key steps in the process by which cancer cells break off from a primary tumor to invade other tissues and form metastases. In their report published in Nature Materials, the investigators describe an stands for epithelial-mesenchymal transition, a fundamental change in cellular characteristics that has been associated with the ability of tumor cells to migrate and invade other sites in the body. Therapies that target this process may be able to slow or halt tumor metastasis.
"This ...