Project description:In S. pombe, about 5% of genes are meiosis-specific and accumulate little or no mRNA during vegetative growth. Here we use Affymetrix tiling arrays to characterize transcripts in vegetative and meiotic cells. In vegetative cells, many meiotic genes, especially those induced in mid-meiosis, have abundant antisense transcripts. These results suggest that antisense transcription represses sense transcription of meiotic genes in vegetative cells. Although the mechanism(s) of antisense mediated transcription repression need to be further explored, our data indicates that RNAi machinery, such as Rdp1, is not required for repression. Previously, we and others used non-strand specific methods to study splicing regulation of meiotic genes and concluded that 28 mid-meiotic genes are spliced only in meiosis. We now demonstrate that the “unspliced” signal in vegetative cells comes from the antisense RNA, not from unspliced sense RNA, andwe argue against the idea that splicing regulates these mid-meiotic genes. Most of these mid-meiotic genes are induced in mid-meiosis by the forkhead transcription factor Mei4. Interestingly, deletion of a different forkhead transcription factor, Fkh2, allows low levels of sense expression of some mid-meiotic genes in vegetative cells. We propose that expression of mid-meiotic genes is kept tightly off in vegetative cells by two independent ways: antisense transcription and Fkh2 repression.
Project description:High-resolution time-course analysis of the fission yeast (S. pombe) cell cycle transcriptional program following synchronization by cdc25 (ts) block and release
Project description:High-resolution time-course analysis of the fission yeast (S. pombe) cell cycle transcriptional program following synchronization by centrifugal elutriation
Project description:3 replicates of WT and srbA knockout strains grown on GMM plates, harvested spores and inoculated 5x10^5 spores/ml in 300 ml of LGMM. Cultures incubated for 10h at 28C and then shifted for 2h to 37C (both at 200rpm) so they are just germinating at the start of the treatment. Cultures were shifted to hypoxia (37C, 200rpm) and incubated for 1hr. Samples were collected by pouring them over a filter paper in a Buechner funnel and snap froze the cells immediately in liquid nitrogen, and stored the cells at -80C and lyophilized all tissue at the same time after all samples were collected. RNA extraction was then done simultaneously with all time points.
Project description:In-vitro-cultured seedlings of WT (Col-0) and all possible combinations of single, double, and triple T-DNA insertion mutants of the cytokinin receptors AHK2 (ahk2-5), AHK3 (ahk3-7) and AHK4 (cre1-2) at growth stage 1.00 were treated for 0, 15 and 120 min with 5micromolar of the synthetic cytokinin 6-benzyladednie (BA).