Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Micro-molecule plays big role in birth defects

20.07.2005


UF Genetics Institute researcher finds way to explore role of microRNAs in specific tissue



University of Florida researchers have learned how to selectively shut down a flyweight-sized genetic molecule that packs a heavyweight punch, a discovery that may help doctors better understand cancer, birth defects and other health problems. The finding, which will be reported this week in the online Proceedings of the National Academy of Sciences, deals with tiny strands of genetic material called microRNAs.

Once thought to be little more than cellular debris, these short strands of RNA may perform a vital role in healthy development by strategically turning off gene activity.


By genetically modifying mice, scientists with the UF Genetics Institute were able to get the first-ever picture of how limbs would develop in a vertebrate without the help of microRNAs. When microRNAs were not available to turn off certain genes, the mice grew malformed, nonfunctional limbs.

The finding may provide insight into human birth defects, but scientists say its greater value will be as a new technique to study the function and malfunction of microRNAs, more than 200 types of which are thought to exist in the human body.

"We looked at limb development because it’s a great place to demonstrate the technique," said Brian Harfe, Ph.D., an assistant professor of molecular genetics and microbiology in the College of Medicine and lead author of the report. "We were able to show it’s feasible to eliminate the activity of microRNAs from a specific tissue while the rest of the tissue remains normal."

Had researchers inhibited microRNAs in every single cell, Harfe said the mouse embryos would survive little more than seven days after fertilization. "That isn’t enough time to study development," Harfe said. "Most structures, such as the heart, the gut and the lungs, haven’t even formed yet. Now we can bypass the problem of early mortality and study the structures as they develop. It’s a new tool for the genetic researcher’s toolbox."

No more than five years ago, microRNAs were considered to be little more than light seasoning in the genetic soup, distant and unnecessary cousins to the main ingredients, DNA, which contains all the genetic instructions for the human body, and RNA, which translates DNA’s message into proteins - the building blocks of life.

Scientists now think the pint-sized pieces of RNA may control as much as one-third of human gene expression by seeking out and binding to messenger RNA, thereby adjusting the protein-manufacturing process.

But for microRNAs to do their jobs, scientists believe an enzyme called Dicer must be present. Harfe, who worked in collaboration with researchers at the University of California at San Francisco and the Harvard Medical School, genetically modified mice so that scientists could eliminate Dicer in specific tissues at any stage in the developmental process, thus opening a window into the role of microRNAs in limb development.

In cases where Dicer is not present in developing limb tissue, Harfe showed that microRNAs were not processed and limbs were visibly smaller. "Many of the birth defects we see in people are mimicked by the defects we’ve seen in this mouse model," said Xin Sun, Ph.D., an assistant professor of genetics at the University of Wisconsin who is familiar with the research but who did not participate in it. "It indicates mutations in microRNAs might be responsible for birth defects, and this has not been discovered before. Using this same approach, we can look at other embryonic organs and ask what microRNAs do as a group."

Other research indicates microRNAs may play a role in diseases ranging from cancer to AIDS. "There is indirect evidence that if you remove two microRNAs from the human genome, leukemia develops," Harfe said. "We envision our mouse model may be a tool to directly test how microRNAs are involved in human cancers."

John Pastor | EurekAlert!
Further information:
http://www.vpha.health.ufl.edu

More articles from Life Sciences:

nachricht Fine organic particles in the atmosphere are more often solid glass beads than liquid oil droplets
21.04.2017 | Max-Planck-Institut für Chemie

nachricht Study overturns seminal research about the developing nervous system
21.04.2017 | University of California - Los Angeles Health Sciences

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

Im Focus: Quantum-physical Model System

Computer-assisted methods aid Heidelberg physicists in reproducing experiment with ultracold atoms

Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...

Im Focus: Glacier bacteria’s contribution to carbon cycling

Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.

A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

New quantum liquid crystals may play role in future of computers

21.04.2017 | Physics and Astronomy

A promising target for kidney fibrosis

21.04.2017 | Health and Medicine

Light rays from a supernova bent by the curvature of space-time around a galaxy

21.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>