Featured Research

from universities, journals, and other organizations

Tiny molecules protect fungi from the dangers of sex

Date:
November 14, 2010
Source:
Duke University Medical Center
Summary:
Pathogenic fungi have been found to protect themselves against unwanted genetic mutations during sexual reproduction, according to researchers. A gene-silencing pathway protects the fungal genome from mutations imposed by a partner during mating.

Pathogenic fungi have been found to protect themselves against unwanted genetic mutations during sexual reproduction, according to researchers at Duke University Medical Center. A gene-silencing pathway protects the fungal genome from mutations imposed by a partner during mating.

Related Articles


This pathway was discovered in Cryptococcus neoformans, a fungus that commonly infects humans, causing over one million cases of lung and brain infection each year, and more than 600,000 deaths. A related species, Cryptococcus gattii, is causing an expanding outbreak in the Pacific Northwest that is of considerable public health impact and concern.

"This discovery of how the genome is protected during sex might be leveraged as an Achilles' heel in the battle against C. neoformans, which frequently causes life-threatening illness in people," said senior author Joseph Heitman, M.D., Ph.D., chair of the Duke Department of Molecular Genetics and Microbiology. "This protective silencing effect also operates in some animals, and our studies demonstrate that the pathway operates to defend the genome during sexual reproduction."

Sexual reproduction in fungi produces airborne spores that are readily inhaled into the lungs and thought to be the source of human infections. Thus, agents that block fungal sex might stop the risk of infection at the source.

This work was published in the Nov. 15 issue of the journal Genes & Development.

C. neoformans uses a novel sex-induced RNAi (RNA interference) genome defense system that protects by effectively "silencing" the DNA, so that it is not vulnerable to repeated genes and transposable elements that could cause mutations.

The silencing system protects the genome from changes that might be imposed by transposable elements of DNA, called "jumping genes," that are also more active during the sexual cycle, said Xuying Wang, Ph.D., a postdoctoral associate who works in the Heitman lab.

Through deep sequencing of the small RNAi pieces which mediate the silencing in C. neoformans, the team also identified abundant small RNAs which map to repetitive transposable elements that could cause mutations if not silenced.

These small RNAs were absent in mutant strains (rdp1) that were studied. One group of transposable elements was greatly expressed during mating of rdp1 mutant strains and these fungi showed an increased transposition and mutation rate in the next generation, leading the researchers to conclude that the RNAi pathway squelches transposon activity during the sexual cycle.

Other authors included co-lead author Yen-Ping Hsueh, now of the California Institute of Technology, and formerly of Duke Molecular Genetics and Microbiology, as well as Wenjun Li, Anna Floyd, and Rebecca Skalsky of Duke Molecular Genetics and Microbiology. The work is supported by the National Institute of Allergy and Infectious Diseases.


Story Source:

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


Cite This Page:

Duke University Medical Center. "Tiny molecules protect fungi from the dangers of sex." ScienceDaily. ScienceDaily, 14 November 2010. <www.sciencedaily.com/releases/2010/11/101114190821.htm>.
Duke University Medical Center. (2010, November 14). Tiny molecules protect fungi from the dangers of sex. ScienceDaily. Retrieved March 6, 2015 from www.sciencedaily.com/releases/2010/11/101114190821.htm
Duke University Medical Center. "Tiny molecules protect fungi from the dangers of sex." ScienceDaily. www.sciencedaily.com/releases/2010/11/101114190821.htm (accessed March 6, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, March 6, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Giant Panda Goes Walkabout in Southwest China

Giant Panda Goes Walkabout in Southwest China

AFP (Mar. 6, 2015) — A giant panda goes walkabout alone at night in southwest China. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
Nesting Bald Eagle Covered in Snow Up to Its Neck

Nesting Bald Eagle Covered in Snow Up to Its Neck

Buzz60 (Mar. 6, 2015) — The Pennsylvania State Game Commission captured amazing shots of a nesting bald eagle who stayed on its nest during a snowstorm, even when the snow piled all the way up to its neck. Jen Markham (@jenmarkham) has the story. Video provided by Buzz60
Powered by NewsLook.com
'Extinct' Bird Isn't Extinct At All, Scientists Find

'Extinct' Bird Isn't Extinct At All, Scientists Find

Buzz60 (Mar. 6, 2015) — Scientists rediscover a bird thought to be extinct, so we may be able to cross it off the "Gone For Good" list. Sean Dowling (@seandowlingtv) has more details. Video provided by Buzz60
Powered by NewsLook.com
Lack of Snow Pushes Alaska Sled Dog Race North

Lack of Snow Pushes Alaska Sled Dog Race North

AP (Mar. 6, 2015) — A shortage of snow has forced Alaska&apos;s Iditarod Trail Sled Dog Race to move 300 miles north to Fairbanks. The ceremonial start through downtown Anchorage will take place this weekend, using snow stockpiled earlier this winter. (March 6) Video provided by AP
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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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