DegrAAAded into silence.
In fission yeast, RNA interference (RNAi)-dependent heterochromatin formation silences transgenes inserted at centromeres. In this issue, Bühler et al. (2007) demonstrate that the RNAi machinery directly targets transgene transcripts. Furthermore, they link transgene silencing to a protein complex resembling the TRAMP complex of budding yeast, which promotes transcript degradation via the exosome. Thus, RNAi-independent transcript degradation may also contribute to heterochromatin gene silencing.
Bayne EH, White SA, Allshire RC