Project description:We used CRISPR/Cas9 to delete the DBP1 ORF in SK1 budding yeast cells. We then used ribosome profiling and mRNA-seq to observe gene expression profiles of wild-type and dbp1∆ cells during meiosis.
Project description:Changes in gene expression are hallmarks of cellular differentiation. Sexual differentiation in fission yeast (Schizosaccharomyces pombe) provides a model system for gene expression programs accompanying and driving cellular specialization. The expression of hundreds of genes is modulated in successive waves during meiosis and sporulation in S. pombe, and several known transcription factors are critical for these processes. We used DNA microarrays to investigate meiotic gene regulation by examining transcriptomes after genetic perturbations (gene deletion and/or overexpression) of rep1, mei4, atf21 and atf31, which encode known transcription factors controlling sexual differentiation. This analysis reveals target genes at a genome-wide scale and uncovers combinatorial control by Atf21p and Atf31p. We also studied two transcription factors that are upregulated during meiosis but had not been previously implicated in sexual differentiation : Rsv2p induces stress-related genes during spore formation, while Rsv1p acts as a repressor for glucose-metabolism genes. Our data further reveal negative feedback interactions: both Rep1p and Mei4p not only activate specific gene expression waves (early and middle genes, respectively), but are also required for repression of genes induced in the previous waves (Ste11p-dependent and early genes, respectively).
Project description:Changes in gene expression are hallmarks of cellular differentiation. Sexual differentiation in fission yeast (Schizosaccharomyces pombe) provides a model system for gene expression programs accompanying and driving cellular specialization. The expression of hundreds of genes is modulated in successive waves during meiosis and sporulation in S. pombe, and several known transcription factors are critical for these processes. We used DNA microarrays to investigate meiotic gene regulation by examining transcriptomes after genetic perturbations (gene deletion and/or overexpression) of rep1, mei4, atf21 and atf31, which encode known transcription factors controlling sexual differentiation. This analysis reveals target genes at a genome-wide scale and uncovers combinatorial control by Atf21p and Atf31p. We also studied two transcription factors that are upregulated during meiosis but had not been previously implicated in sexual differentiation : Rsv2p induces stress-related genes during spore formation, while Rsv1p acts as a repressor for glucose-metabolism genes. Our data further reveal negative feedback interactions: both Rep1p and Mei4p not only activate specific gene expression waves (early and middle genes, respectively), but are also required for repression of genes induced in the previous waves (Ste11p-dependent and early genes, respectively).
Project description:Inactivation of the yeast IME4 gene, the yeast homologue of METTL3, was shown to result in the loss of m6A in mRNA of mutant cells grown in sporulation medium. We attempted to characterize the effects of ime4 deletion on gene expression under vegetative and meiosis-inducing conditions. The results show that in vegetatively-growing ime4-/- cells there is an increased expression of the RME1 gene (repressor of meiosis) which prevents precocious entry into the meiotic program. Mutant yeast cells showed reduced expression levels of genes involved in ribosome biogenesis and gene expression processes. Surprisingly, despite the fact that a diploid strain was analyzed, there was also a striking change in the expression level of haploid-specific genes, suggesting that RNA methylation may be used to enforce the sexual identity of diploid cells, required for the implementation of the gametogenesis program. Consistently, when cells were induced to undergo meiosis, ime4-/- diploids failed to undergo the meiotic divisions. Among the genes showing reduced expression in the mutant were IME1 and IME2, the two known inducers of meiosis. Thus, the yeast IME4 gene plays an important role in the regulation of the developmental switch from vegetative cells into gametogenesis.
Project description:We have analysed the activity of the nuclear exosome during meiosis by deletion of TRF4, which encodes a key component of the exosome targeting complex TRAMP. We find that TRAMP mutants produce high levels of CUTs during meiosis that are undetectable in wild-type cells, showing that the nuclear exosome remains functional for CUT degradation. Lack of TRAMP activity stabilises ~1600 CUTs in meiotic cells, which occupy 40% of the binding capacity of the nuclear cap binding complex (CBC).
Project description:We studied the meiotic regulation of transcription, by comparing the mRNA level at time t=1h to t=8h after meiosis induction, to the mRNA level at time t=0h. Keywords: yeast meiotic time course, transcriptome
Project description:Dynamic proteome in diploid yeast cells undergoing mitotic growth and meiotic development. The proteome of growing (YPA) and differentiating yeast cells at 6 hours (SPII 6, middle meiosis) and 8 hours (SPII8, late meiosis) were compared using the TOP3 GeLC-MS/MS method.