Silencing in trans: position matters in fission yeast.
The distinction in RNAi-mediated gene silencing between metazoans —which mostly use a post-transcriptional RNAi mechanism— and fission yeast —which use a transcriptional RNAi mechanism— seems to be less clear-cut than previously thought. Robin Allshire's group has recently published in  EMBO reports  that  S. pombe  can repress gene expression in  trans , which is reminiscent of mammalian post-transcriptional gene silencing.
Gullerova M, Proudfoot NJ