Navigation Links
MicroRNA may have fail-safe role in limb development

A tiny strand of molecules plays a role in how our arms and legs develop and grow - a finding that sheds light on perplexing bits of material once dismissed as genetic "junk," say scientists at the University of Florida and Harvard University.

The research, available today in the online edition of Nature, may help scientists understand whether bits of RNA called microRNAs act as protective mechanisms in healthy development not just by strategically turning off gene activity, but by making sure it stays turned off.

More specifically, researchers report linking a specific microRNA - miR 196 - to limb development, a finding that may be useful in understanding birth defects.

Until about five years ago, genetic researchers focused on DNA, which contains all the genetic instructions for the human body, and RNA, which translates DNA's message into proteins - the building blocks of cells, organs and all of the various systems of the body.

Unnoticed next to the main ingredients, microRNAs were considered to be "junk" DNA, leftovers from millions of years of evolution. More recently, this genetic material is suspected to be part of an intricate mechanism that helps repress about one-third of our 25,000 genes. It has been linked to diabetes, hepatitis C, leukemia, lymphoma and breast cancer.

But only now have microRNAs been connected to actual growth processes.

"We found miR 196 expressed only in the hindlimbs of mice, not the forelimbs - in other words, the feet but not the hands," said Brian Harfe, Ph.D., an assistant professor of molecular genetics and microbiology in the College of Medicine and a member of the UF Genetics Institute. "In developmental biology, there has always been debate about why forelimbs are different from hindlimbs. We now think this microRNA is regulating something important in the hindlimbs but not in the forelimbs."

Scientists do not know exactly what is happening, but they think miR 196 acts a s a protective mechanism in the hindlimbs in the event normal gene transcription goes awry.

"A large body of evidence indicates this new class of regulators is not something to turn things off in the first place, but a fail-safe," said Clifford Tabin, Ph.D., a professor of genetics at Harvard Medical School and senior author of the research. "You don't want cells in a hindlimb seeing cells that should only be in a forelimb - it would create a defective limb. So you not only want to shut the faucet tight on the wrong cells, you want to shove a towel into it, too, to really make sure the wrong thing doesn't leak out. One way of doing that is with microRNA."

Researchers looked at gene activity in chicken embryos and in mice, finding miR-196 silences a chemical important for transferring information from DNA to RNA within a cell - a transcription factor.

"It's turning off a transcription factor in the hindlimb that is important for forelimb development," Harfe said. "But it still doesn't explain why a hindlimb is a hindlimb and a forelimb is a forelimb."

The next step in the research is to observe limb development in mice engineered to not express miR 196.

"The authors have shown a role for miR 196 in limb development," said John Fallon, the University of Wisconsin's Harland Winfield Mossman professor of anatomy. "People talked about ways microRNA may have a role in embryonic development, and this work is a solid contribution that supports that idea. Researchers have also been looking for differences between gene expression in forelimbs and hindlimbs, with little success. This paper suggests there is a new mechanism to control the fidelity of protein expression in the limbs through microRNA expression. That is a hypothesis that people in the field will have to test, but it is strongly supported by their research."


'"/>

Source:University of Florida


Related biology news :

1. Yale Scientists Find MicroRNA Regulates Ras Cancer Gene
2. Cooperation is key—a new way of looking at MicroRNA and how it controls gene expression
3. MicroRNAs play a big part in gene regulation - and evolution
4. MicroRNA tweaks protein that controls early heart development
5. MicroRNAs have shaped the evolution of the majority of mammalian genes
6. MicroRNA gene that regulates lifespan found by Yale scientists
7. MicroRNAs can be tumor suppressors
8. MicroRNA helps prevent tumors
9. MicroRNAs as tumor suppressors
10. A much-needed shot in the arm for HIV vaccine development
11. Clam embryo study shows pollutant mixture adversely affects nerve cell development
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:5/16/2016)... --  EyeLock LLC , a market leader of iris-based ... IoT Center of Excellence in Austin, Texas ... embedded iris biometric applications. EyeLock,s iris authentication ... with unmatched biometric accuracy, making it the most proven ... platform uses video technology to deliver a fast and ...
(Date:4/28/2016)... India , April 28, 2016 ... Infosys (NYSE: INFY ), and Samsung SDS, a ... that will provide end customers with a more secure, ... services.      (Logo: http://photos.prnewswire.com/prnh/20130122/589162 ) , ... services, but it also plays a fundamental part in enabling ...
(Date:4/19/2016)... The new GEZE SecuLogic access ... "all-in-one" system solution for all door components. It can ... door interface with integration authorization management system, and thus ... minimal dimensions of the access control and the optimum ... offer considerable freedom of design with regard to the ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... 2016 Houston Methodist Willowbrook Hospital has ... Association to serve as their official health care ... Willowbrook will provide sponsorship support, athletic training services, ... coaches, volunteers, athletes and families. "We ... Association and to bring Houston Methodist quality services ...
(Date:6/23/2016)... , June, 23, 2016  The Biodesign Challenge ... envision new ways to harness living systems and biotechnology, ... Art (MoMA) in New York City ... 130 participating students, showcased projects at MoMA,s Celeste Bartos ... Paola Antonelli , MoMA,s senior curator of architecture and ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... STACS DNA ... Technical Leader at the Arkansas State Crime Laboratory, has joined STACS DNA as a ... STACS DNA team,” said Jocelyn Tremblay, President and COO of STACS DNA. “In further ...
(Date:6/23/2016)... 2016  Blueprint Bio, a company dedicated to identifying, ... community, has closed its Series A funding round, according ... "We have received a commitment from Forentis Fund ... to meet our current goals," stated Matthew Nunez ... to complete validation on the current projects in our ...
Breaking Biology Technology: