Latest Piwi Stories

Epigenetic memory may pass RNA silencing from 1 generation to the next Organisms employ a fascinating array of strategies to identify and restrain invasive pieces of foreign DNA, such as those introduced by viruses. For example, many viruses produce double-stranded (ds)RNA during their life cycle and the RNA interference (RNAi) mechanism is thought to recognize this structural feature to initiate a silencing response. Now, UMass Medical School researchers have identified a mechanism...

Small RNA-based nucleic acid drugs represent a promising new class of therapeutic agents for silencing abnormal or overactive disease-causing genes, and researchers have discovered new mechanisms by which RNA drugs can control gene activity. A comprehensive review article in Nucleic Acid Therapeutics, a peer-reviewed journal published by Mary Ann Liebert, Inc., details these advances. Short strands of nucleic acids, called small RNAs, can be used for targeted gene silencing, making them...

New research illustrates how the genome adapts to a transposon invasion Small, mobile sequences of DNA left over from viruses, called transposons or "jumping genes" because of their ability to move around the genome, pose a significant threat to the genetic integrity and stability of an organism. Considered genetic parasites, these transposable elements are believed to comprise as much as 50 percent of the human genome. Because of the damage transposons can do to an organism's DNA, an...

Berkeley Researchers Get First Look at Gene-Silencing Human RISC-Loading ComplexThe molecular architecture of a protein complex that helps determine the fate of human cells has been imaged for the first time by researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab). Known as a human RISC-loading complex, this structure consists of snippets of ribonucleic acid (RNA) that control whether genetic messages are silenced or expressed.From these new...

A class of small RNAs inherited from the mother determines offspring's fertility traitHereditary information flows from parents to offspring not just through DNA but also through the millions of proteins and other molecules that cling to it. These modifications of DNA, known as "epigenetic marks," act both as a switch and a dial "“ they can determine which genes should be turned on or off, and how much message an "on" gene should produce.One way in which epigenetic...

Tekmira Pharmaceuticals has announced that one of its collaborators, the National Cancer Institute, has presented promising preclinical data treating liver cancer using small interfering RNA enabled by the company's stable nucleic acid-lipid particles delivery technology. Scientists at the National Cancer Institute's (NCI's) Laboratory of Experimental Carcinogenesis and the surgery branch of the NCI worked in collaboration with Tekmira scientists to develop small interfering RNA (siRNA) to...