Project description:Gene number of the fission yeast Schizosaccharomyces pombe is the lowest in free-living eukaryotes. We further reduced the gene number to examine a minimal gene set required for growth. The genome-reduced strain, named ASP3894, has four chromosomal deletion regions: 168.4 kb deletion in the left arm of chromosome 1 (ALT), 155.4 kb deletion in the right arm of chromosome 1 (ART), 211.7 kb deletion in the left arm of chromosome 2 (BLT) and 121.6 kb deletion in the right arm of chromosome 2 (BRT). As a result of the 657.3 kb genome reduction, 224 genes of approximately 5100 total genes were reduced. ASP3894 transcriptional profiling was compared with a parent strain, ASP3880, that is a non-genome-reduced strain to examine the influence of genome reduction.
Project description:Hrp3_Purification from Schizosaccharomyces pombe 972h- Eukaryotic genome is composed of repeating units of nucleosomes to form chromatin arrays. A canonical gene is marked by nucleosome free region (NFR) at its 5’ end followed by uniformly spaced arrays of nucleosomes. In fission yeast we show both biochemically and in vivo that both Hrp1 and Hrp3 are key determinants of uniform spacing of genic arrays.
Project description:Experimental evolution studies with microorganisms such as bacteria and yeast have been an increasingly important and powerful tool to draw long-term inferences of how microbes interact. However, while several strains of the same species often exist in natural environments, many ecology and evolution studies in microbes are typically performed with isogenic populations of bacteria or yeast. In the present study, we firstly perform a genotypic and phenotypic characterization of two laboratory and eight natural strains of the yeast Schizosaccharomyces pombe. We then propagated, in a rich resource environment, yeast communities of 2, 3, 4, and 5 strains for hundreds of generations and asked which fitness-related phenotypes-maximum growth rate or relative competitive fitness-would better predict the outcome of a focal strain during the propagations. While the strain's growth rates would wrongly predict long-term coexistence, pairwise competitive fitness with a focal strain qualitatively predicted the success or extinction of the focal strain by a simple multigenotype population genetics model, given the initial community composition. Interestingly, we have also measured the competitive fitness of the ancestral and evolved communities by the end of the experiment (≈370 generations) and observed frequent maladaptation to the abiotic environment in communities with more than three members. Overall, our results aid establishing pairwise competitive fitness as good qualitative measurement of long-term community composition but also reveal a complex adaptive scenario when trying to predict the evolutionary outcome of those communities.
Project description:Opi10 is the S. pombe homolog of human Hikeshi, which imports Hsp70s into the nucei during the heat shock. We compared the gene expression of the S. pombe opi10+ and opi10- strains before, during and after the heat shock.