Navigation Links
Tiny molecules protect from the dangers of sex
Date:11/14/2010

DURHAM, N.C. 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.

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.


'/>"/>

Contact: Mary Jane Gore
mary.gore@duke.edu
919-660-1309
Duke University Medical Center
Source:Eurekalert

Related biology news :

1. Of 50,000 small molecules tested to fight cancer, 2 show promise
2. Study identifies key molecules in multiple myeloma
3. New class of biomolecules triggered in response to respiratory virus infection
4. Scientists trick bacteria with small molecules
5. MIT researchers develop a better way to see molecules at work in living brain cells
6. Scientists identify molecules involved in touch and other mechanically activated systems
7. Juelich researchers take a look inside molecules
8. Molecules delivering drugs as they walk
9. Nanoblasts from laser-activated nanoparticles move molecules, proteins and DNA into cells
10. Correcting a trick of the light brings molecules into view
11. Molecules typically found in blue jean and ink dyes may lead to more efficient solar cells
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/13/2017)... 2017 UBM,s Advanced Design and Manufacturing event ... emerging and evolving technology through its 3D Printing and ... alongside the expo portion of the event and feature ... focused on trending topics within 3D printing and smart ... event will take place June 13-15, 2017 at the Jacob ...
(Date:4/11/2017)... 2017 No two people are believed ... New York University Tandon School of Engineering and ... that partial similarities between prints are common enough ... phones and other electronic devices can be more ... lies in the fact that fingerprint-based authentication systems ...
(Date:4/5/2017)... YORK , April 5, 2017 Today ... is announcing that the server component of the HYPR ... known for providing the end-to-end security architecture that empowers ... HYPR has already secured over 15 million ... makers including manufacturers of connected home product suites and ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... , Oct. 10, 2017 SomaGenics announced ... the NIH to develop RealSeq®-SC (Single Cell), expected to ... profiling small RNAs (including microRNAs) from single cells using ... highlights the need to accelerate development of approaches to ... "New techniques for measuring levels of ...
(Date:10/9/2017)... ... , ... The award-winning American Farmer television series will feature 3 Bar Biologics ... at 8:30aET on RFD-TV. , With global population estimates nearing ten billion people ... to feed a growing nation. At the same time, many of our valuable resources ...
(Date:10/7/2017)... , ... October 06, 2017 ... ... experience providing advanced instruments and applications consulting for microscopy and surface analysis, ... in application consulting, Nanoscience Analytical offers a broad range of contract analysis ...
(Date:10/6/2017)... ... October 06, 2017 , ... On ... and webinar on INSIGhT, the first-ever adaptive clinical trial for glioblastoma (GBM). The ... The event is free and open to the public, but registration is required. ...
Breaking Biology Technology: