Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dartmouth Medical School geneticists discover new role for antisense RNA

28.02.2003


Dartmouth Medical School geneticists studying the biological clock have opened yet another window into the role of an unusual form of RNA known as antisense that blocks the messages of protein-encoding genes.



They found that antisense RNA appears to regulate core timing genes in the circadaian clock that drives the 24-hour light-dark cycle of Neurospora, a model organism better known as bread mold.

The results are reported in the February 27 Nature by Drs. Jennifer Loros and Jay C. Dunlap, both DMS professors, and Susan K. Crosthwaite, formerly a postdoctoral fellow at DMS, and Cas Kramer, both of the University of Manchester, England.


Messenger RNA, which has a single-stranded sequence of nucleotides, is called "sense" because it can be decoded to produce a gene product (a protein). Like DNA, this mRNA can form duplexes with a second strand of RNA whose base sequence is complementary to the first strand. The second strand is called the antisense strand because its nucleotide sequence is the complement of "sense" message. When mRNA forms a duplex with a complementary antisense RNA sequence, the message translation is turned off so the sense strand can no longer be decoded to yield a protein product.

As scientists identify more antisense RNAs, they are beginning to realize these might affect a wide variety of processes. The recent findings, write the authors, "provide an unexpected link between antisense RNA and circadian timing."

Studying the development of spores in the bread mold Neurospora, Dunlap and Loros have teased apart the molecular gears that form the basis of most living clocks. Light and dark cycles reset the clocks, they found, the way turning the hands of a clock does. The clock mechanism, a biological oscillator, keeps time through the delicately balanced interplay of the Neurospora clock genes and proteins in a complex of feedback loops.

"We found a long RNA antisense transcript that arises from the frequency gene, known to encode factors important for the operation of the circadian clock in Neurospora," says Dunlap. "The sense transcript encodes proteins that are involved in the feedback loop that is the oscillator in the clock. The antisense transcript runs in the opposite direction, and apparently does not encode a protein, so its actual role is unknown at present. It may simply bock translation, or it may destabilize the sense message. Antisense transcripts are already known, but usually they are quite small, on the order of 20 to 25 bases. This one is quite large, nearly 5,000 bases."

In normal bread mold strains living in the dark, levels of antisense frequency transcripts cycle with respect to the amount of sense frequency transcripts, and they are inducible by light, the researchers determined. However, in strains mutated to abolish induction of antisense frequency RNA by light, the internal clock time was delayed, and resetting of the clock by light was altered.

If similar environmental factors regulate both sense and antisense transcripts, the authors suggest, a role for antisense frequency RNA might be to confer the ability to keep accurate time by limiting the clock response to extremes in the environment. Likewise other antisense RNAs might be involved in maintaining internal stability in other organisms.

DMS Communications | EurekAlert!
Further information:
http://www.dartmouth.edu/

More articles from Life Sciences:

nachricht Nonstop Tranport of Cargo in Nanomachines
20.11.2018 | Max-Planck-Institut für molekulare Zellbiologie und Genetik

nachricht Researchers find social cultures in chimpanzees
20.11.2018 | Universität Leipzig

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nonstop Tranport of Cargo in Nanomachines

Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.

Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

Nonstop Tranport of Cargo in Nanomachines

20.11.2018 | Life Sciences

Researchers find social cultures in chimpanzees

20.11.2018 | Life Sciences

When AI and optoelectronics meet: Researchers take control of light properties

20.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>