Tiny molecules that protect from dangers of sex identified
By ANIMonday, November 15, 2010
WASHINGTON - Scientists have discovered a gene-silencing pathway that protects 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.
This pathway was discovered in Cryptococcus neoformans, a fungus that commonly infects humans.
“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 Joseph Heitman.
“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.
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 team also identified abundant small RNAs, which map to repetitive transposable elements that could cause mutations if not silenced.
This work was published in the Nov. 15 issue of the journal Genes and Development. (ANI)
