Project description:We test the effects of overexpressing RNAi proteins Dcr1, Rdp1, or Ago1 in wildtype, dcr1M-bM-^HM-^F, ago1M-bM-^HM-^F, or rdp1M-bM-^HM-^F cells. We find that overexpression does not generally affect H3K9me2 at euchromatic loci, but there are varying effects in H3K9me2 on centromeric heterochromatin. Examination of genome-wide enrichment in H3K9 dimethylation in fission yeast haploid cells
Project description:RNA interference (RNAi) is a gene silencing mechanism conserved from fungi to mammals. Small interfering RNAs are products and mediators of the RNAi pathway and act as specificity factors in recruiting effector complexes. The Schizosaccharomyces pombe genome encodes one of each of the core RNAi proteins, Dicer, Argonaute and RNA-dependent RNA polymerase (dcr1, ago1, rdp1). Even though the function of RNAi in heterochromatin assembly in S. pombe is established, its role in controlling gene expression is elusive. Here, we report the identification of small RNAs mapped anti-sense to protein coding genes in fission yeast. We demonstrate that these genes are up-regulated at the protein level in RNAi mutants, while their mRNA levels are not significantly changed. We show that the repression by RNAi is not a result of heterochromatin formation. Thus, we conclude that RNAi is involved in post-transcriptional gene silencing in S. pombe.
