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:6/3/2016)... , June 3, 2016 ... Management) von Nepal ... und Lieferung hochsicherer geprägter Kennzeichen, einschließlich Personalisierung, ... führend in der Produktion und Implementierung von ... der Ausschreibung im Januar teilgenommen, aber Decatur ...
(Date:6/2/2016)... June 2, 2016   The Weather Company , an ... Ads, an industry-first capability in which consumers will be able ... to ask questions via voice or text and receive relevant ... Marketers have long sought an advertising solution ... can be personal, relevant and valuable; and can scale across ...
(Date:6/1/2016)... , June 1, 2016 ... in Election Administration and Criminal Identification to Boost Global ... a recently released TechSci Research report, " Global Biometrics ... Region, Competition Forecast and Opportunities, 2011 - 2021", the ... billion by 2021, on account of growing security concerns ...
Breaking Biology News(10 mins):
(Date:11/30/2016)... BEIJING , Nov. 30, 2016 Novogene ... services and solutions with cutting edge next-generation sequencing (NGS) ... a USD $75 Million [515 Million RMB] B round ... Capital Management ( Shenzhen ) Co., Ltd. ... Innovation") and Shanghai Sigma Square Investment Center LP ("Sigma ...
(Date:11/30/2016)... 30, 2016   Merck , a leading science ... into a set of agreements with Evotec AG, whereby ... of genetic reagents such as CRISPR and shRNA libraries. ... offers an accelerated pathway to explore and identify new ... identification of new targets, a process that can be ...
(Date:11/30/2016)... NC (PRWEB) , ... November 30, 2016 , ... ... engaged in the development of a new orally administered treatment for Alzheimer’s disease ... neuroimaging results of a Phase 2a clinical trial of T3D-959 in mild to ...
(Date:11/30/2016)... ... 30, 2016 , ... ProMIS Neurosciences (“ProMIS” or the “Company”), ... today announced that all five of its validated monoclonal antibody (mAb) therapeutic candidates ... prion-like forms of Amyloid beta (Aß) in vitro. , “We previously demonstrated that ...
Breaking Biology Technology: