Navigation Links
Micro-molecule plays big role in birth defects

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."


'"/>

Source:University of Florida


Related biology news :

1. White blood cell waste disposal system plays critical regulatory role
2. Sleeping beauty plays a significant role in identifying cancer genes
3. Neural stem cell gene plays crucial role in eye development
4. Got inexpensive contrast agent? Milk plays new role in imaging
5. Zinc plays important role in brain circuitry
6. Fish species plays surprise role in aiding coral reef recovery
7. Anticipation plays a powerful role in human memory, brain study finds
8. Motor protein plays key role in connecting neurons
9. Confirmed -- deforestation plays critical climate change role
10. Scientists document complex genomic events leading to the birth of new genes
11. One hit of crystal meth causes birth defects
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:2/1/2016)... NEW YORK , Feb. 1, 2016  Today, ... Heart Association (AHA) announced plans to develop a first ... cognitive computing power of IBM Watson. In the first ... disease, AHA, IBM (NYSE: IBM ), and Welltok ... metrics and health assessments with cognitive analytics, delivered on ...
(Date:1/25/2016)... 2016   Unisys Corporation (NYSE: UIS ) today ... (JFK) International Airport, New York City , to ... attempting to enter the United States using ... pilot testing of the system at Dulles last year. ... JFK during January 2016. --> pilot testing of ...
(Date:1/21/2016)... 2016 --> ... research report "Emotion Detection and Recognition Market by Technology (Bio-Sensors, ... Expression, Voice Recognition and Others), Services, Application Areas, ... 2020", published by MarketsandMarkets, the global Emotion Detection ... 22.65 Billion by 2020, at a CAGR of ...
Breaking Biology News(10 mins):
(Date:2/12/2016)... ... February 12, 2016 , ... The ... Center in Atlanta, Georgia, will include 848 exhibitors (count as of February 9) ... displaying products and services used by the scientific community in industrial, academic, and ...
(Date:2/11/2016)... (NASDAQ: NBIX ) today announced its financial results for the ... --> --> For the fourth quarter of 2015, ... loss per share, compared to a net loss of $19.4 million, ... For the year ended December 31, 2015, the Company reported a ... compared to a net loss of $60.5 million, or $0.81 loss ...
(Date:2/11/2016)... 2016  Wellcentive today announced it has been ... -based community care organization (CCO) with more ... quality reporting and care management solutions and services. ... of quality managers, analysts and care managers while ... serving FamilyCare members. Oregon ...
(Date:2/11/2016)... ... February 11, 2016 , ... Reichert Technologies, which has created ... pursue the highest level of accuracy and quality with the addition of two ... AR5 Refractometer. Accurate, reliable and tough enough for the most demanding applications, ...
Breaking Biology Technology: