Science doi:10.1126/science.1176945 (2009)

It seemed a stubborn exception. One of the most useful research tools, gene silencing by RNA interference (RNAi), can't be used in a laboratory workhorse organism, the yeast Saccharomyces cerevisiae. Indeed, it was thought that the ability to do RNAi had been lost from all budding yeast species at some point in evolution.

But David Bartel of the Massachusetts Institute of Technology in Cambridge and his colleagues took a closer look at some related yeast species. They found all the necessary components of the RNAi pathway, including a previously unknown version of the Dicer protein, which is essential to the process.

By putting the components into S. cerevisiae, they were able to kick-start the pathway, potentially opening up new research directions for both the organism and the nature of gene silencing.