Featured Research

from universities, journals, and other organizations

Dartmouth Medical School Geneticists Discover New Role For Antisense RNA

Date:
February 28, 2003
Source:
Dartmouth Medical School
Summary:
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.

Hanover, NH – 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.


Story Source:

The above story is based on materials provided by Dartmouth Medical School. Note: Materials may be edited for content and length.


Cite This Page:

Dartmouth Medical School. "Dartmouth Medical School Geneticists Discover New Role For Antisense RNA." ScienceDaily. ScienceDaily, 28 February 2003. <www.sciencedaily.com/releases/2003/02/030228072503.htm>.
Dartmouth Medical School. (2003, February 28). Dartmouth Medical School Geneticists Discover New Role For Antisense RNA. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2003/02/030228072503.htm
Dartmouth Medical School. "Dartmouth Medical School Geneticists Discover New Role For Antisense RNA." ScienceDaily. www.sciencedaily.com/releases/2003/02/030228072503.htm (accessed August 22, 2014).

Share This




More Health & Medicine News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Two US Ebola Patients Leave Hospital Free of the Disease

Two US Ebola Patients Leave Hospital Free of the Disease

AFP (Aug. 21, 2014) Two American missionaries who were sickened with Ebola while working in Liberia and were treated with an experimental drug are doing better and have left the hospital, doctors say on August 21, 2014. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Cadavers, a Teen, and a Medical School Dream

Cadavers, a Teen, and a Medical School Dream

AP (Aug. 21, 2014) Contains graphic content. He's only 17. But Johntrell Bowles has wanted to be a doctor from a young age, despite the odds against him. He was recently the youngest participant in a cadaver program at the Indiana University NW medical school. (Aug. 21) Video provided by AP
Powered by NewsLook.com
American Ebola Patients Released: What Cured Them?

American Ebola Patients Released: What Cured Them?

Newsy (Aug. 21, 2014) It's unclear whether the American Ebola patients' recoveries can be attributed to an experimental drug or early detection and good medical care. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins