The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
Hironori Niki - One of the best experts on this subject based on the ideXlab platform.
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Mating, Spore Dissection, and Selection of Diploid Cells in Schizosaccharomyces japonicus.
Cold Spring Harbor protocols, 2017Co-Authors: Kanji Furuya, Hironori NikiAbstract:Haploid yeast cells mate to form heterozygotes and subsequently undergo meiosis to form spores. This process can be used to produce gene combinations and variants that are useful for genetic analysis. For example, these spores can be used to generate double mutants or to measure genetic distances in a mutational analysis. Here, we describe mating and spore dissection procedures for Schizosaccharomyces japonicus cells. Although the overall procedures resemble those used in Schizosaccharomyces pombe, some differences exist, including the use of EMM2 medium without nitrogen (EMM-N) for mating and the shorter incubation time of 16-20 h for S. japonicus cells. Furthermore, the S. japonicus zygotes produce eight spores and thus require an "octad" analysis.
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Transformation of Schizosaccharomyces japonicus.
Cold Spring Harbor protocols, 2017Co-Authors: Keita Aoki, Hironori NikiAbstract:This protocol describes the use of electroporation to transform Schizosaccharomyces japonicus with plasmids or linear DNA. Plasmids are helpful for the complementation testing of mutations and for the expression of specific genes. Linear DNA fragments integrated into chromosomal DNA by homologous recombination are useful for gene deletion or to fuse a gene with a tag sequence (e.g., encoding a fluorescent protein). To introduce DNA into S. japonicus, electroporation methods are recommended because S. japonicus is sensitive to lithium acetate (LiOAc).
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Induction of Hyphal Growth in Schizosaccharomyces japonicus.
Cold Spring Harbor protocols, 2017Co-Authors: Hironori NikiAbstract:Schizosaccharomyces japonicus is a dimorphic yeast. Depending on the nutrient conditions, the transition between growth as yeast cells and growth as hyphal cells can be reversibly induced. In addition to nutrient stress, induced DNA lesions, such as those produced by camptothecin, also induce hyphal growth regardless of the nutrient status. This protocol describes both methods of induction.
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Mating response and construction of heterothallic strains of the fission yeast Schizosaccharomyces octosporus.
FEMS yeast research, 2017Co-Authors: Taisuke Seike, Hironori NikiAbstract:The fission yeast Schizosaccharomyces octosporus is one of four species in the genus Schizosaccharomyces. Recently released genome sequence data provide useful information for comparative studies. However, Sz. octosporus has not yet been genetically characterized because there have been no heterothallic strains of this species. Here we report the construction of stable heterothallic strains of Sz. octosporus for genetic crosses. First, we continuously observed the mating process of a homothallic strain, yFS286, and determined the mating frequency of Sz. octosporus on various sporulation media. It showed, on average, 30% zygote formation on mating, and a higher frequency of zygotes (43.8 ± 4.7%) on PMG medium. Regardless of sporulation, the number of spores within an ascus was variable. Schizosaccharomyces octosporus forms eight-spored asci, but preferentially produced four-spored asci on MEA or YMoA medium. To obtain heterothallic strains essential for genetic analyses, we isolated spontaneous mutants showing heterothallic-like phenotypes. We also constructed stable heterothallic strains by deleting the silent mat region. As a result, we established the following heterothallic strains, TS162 as h+ and TS150/TS161 as h-, which successfully mated with each other. These genetic tools will be useful for yeast genetics such as molecular cloning, gene complementation tests and tetrad (octad) analysis.
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Isolation of heterothallic haploid and auxotrophic mutants of Schizosaccharomyces japonicus.
Yeast (Chichester England), 2009Co-Authors: Kanji Furuya, Hironori NikiAbstract:The fission yeast Schizosaccharomyces japonicus var. japonicus belong to the genus Schizosaccharomyces, together with Schizosaccharomyces pombe, which has been well studied as a model organism. In contrast, Sz. japonicus is poorly characterized and genetic tools were yet to be developed. We here report the isolation of the heterothallic haploids NIG2017, NIG2025 and NIG2028, which were derivatives of a Sz. japonicus homothallic strain (NIG2008). Based on the genomic sequence of Sz. japonicus, released by the Broad Institute, we found that Sz. japonicus also possesses orthologues of the mating-type genes of Sz. pombe; two mat-M (-) and two mat-P (+) genes. As expected, heterothallic strains were defective in one of the Sz. japonicus mat genes (mat(sj)). We confirmed that NIG2017 and NIG2025 strains only expressed mRNA from the mat(sj)-P genes, while homothallic strains expressed both mat(sj)-M and mat(sj)-P. Although the NIG2028 strain expressed both gene products, mat(sj)-P was found mutated, which may have conferred the heterothallic phenotype of the mutant. Thus, we concluded that these were stable heterothallic strains. We designated NIG2017 and NIG2025 as h(+) and NIG 2028 as h(-), respectively. We also found additional h(-) strains (NIG5872 and NIG5873) that arose from the cross between NIG2017 and NIG2028 derivatives. In addition to that, we have constructed a ura4(sj)-deleted strain and an ade6(sj)-mutated strain. We used these heterothallic strains and the auxotroph strains to perform spore dissection analysis to determine the genetic distances between several loci, and found that the mating type loci and ade6(sj) locus were linked to centromeres.
K. Wolf - One of the best experts on this subject based on the ideXlab platform.
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Nucleotide sequence of the Schizosaccharomyces japonicus var. versatilis ribosomal RNA gene cluster and its phylogenetic implications
Current genetics, 1995Co-Authors: Joerg Naehring, Stefan Kiefer, K. WolfAbstract:Fission yeasts form a small but heterogeneous group of ascomycetes and it is still unclear whether they should be subdivided into three genera (Schizosaccharomyces, Octosporomyces, Hasegawaea) or remain a single genus (Schizosaccharomyces). In order to decide whether a new genus Hasegawaea should be established for the species Schizosaccharomyces japonicus and Schizosaccharomyces versatilis, we have characterized the entire rDNA cluster in Schizosaccharomyces japonicus var. versatilis and compared it with the homologous region from Schizosaccharomyces pombe and with complete rRNA gene sequences from other yeast genera. From a phage genomic library a recombinant lambda phage containing the entire rDNA repeat unit was isolated. In this paper we report the primary sequence of the 18s, 5.8s and 25s rRNA coding regions. The S. japonicus var. versatilis rRNA genes are 1823 (18s), 158 (5.8s) and 3422 (25s) nucleotides long. The two sequences of the larger rRNA genes exhibit 95.7% (18s) and 93% (25s) similarity with the homologous genes from S. pombe. The differences between the rRNA genes of S. japonicus and S. pombe, however, are much smaller than the intrageneric differences within the rDNA sequences of other yeast genera. Therefore, subdivision of fission yeasts into the genera Schizosaccharomyces and Hasegawaea does not to seem to be justified. The sequence has been deposited in the EMBL data bank under the accession number Z 32848.
Yasushi Hiraoka - One of the best experts on this subject based on the ideXlab platform.
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orfeome cloning and global analysis of protein localization in the fission yeast Schizosaccharomyces pombe
Nature Biotechnology, 2006Co-Authors: Akihisa Matsuyama, Ritsuko Arai, Yoko Yashiroda, Atsuko Shirai, Ayako Kamata, Shigeko Sekido, Yumiko Kobayashi, Atsushi Hashimoto, Makiko Hamamoto, Yasushi HiraokaAbstract:ORFeome cloning and global analysis of protein localization in the fission yeast Schizosaccharomyces pombe
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Corrigendum: ORFeome cloning and global analysis of protein localization in the fission yeast Schizosaccharomyces pombe
Nature Biotechnology, 2006Co-Authors: Akihisa Matsuyama, Ritsuko Arai, Yoko Yashiroda, Atsuko Shirai, Ayako Kamata, Shigeko Sekido, Yumiko Kobayashi, Atsushi Hashimoto, Makiko Hamamoto, Yasushi HiraokaAbstract:Corrigendum: ORFeome cloning and global analysis of protein localization in the fission yeast Schizosaccharomyces pombe
Joerg Naehring - One of the best experts on this subject based on the ideXlab platform.
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Nucleotide sequence of the Schizosaccharomyces japonicus var. versatilis ribosomal RNA gene cluster and its phylogenetic implications
Current genetics, 1995Co-Authors: Joerg Naehring, Stefan Kiefer, K. WolfAbstract:Fission yeasts form a small but heterogeneous group of ascomycetes and it is still unclear whether they should be subdivided into three genera (Schizosaccharomyces, Octosporomyces, Hasegawaea) or remain a single genus (Schizosaccharomyces). In order to decide whether a new genus Hasegawaea should be established for the species Schizosaccharomyces japonicus and Schizosaccharomyces versatilis, we have characterized the entire rDNA cluster in Schizosaccharomyces japonicus var. versatilis and compared it with the homologous region from Schizosaccharomyces pombe and with complete rRNA gene sequences from other yeast genera. From a phage genomic library a recombinant lambda phage containing the entire rDNA repeat unit was isolated. In this paper we report the primary sequence of the 18s, 5.8s and 25s rRNA coding regions. The S. japonicus var. versatilis rRNA genes are 1823 (18s), 158 (5.8s) and 3422 (25s) nucleotides long. The two sequences of the larger rRNA genes exhibit 95.7% (18s) and 93% (25s) similarity with the homologous genes from S. pombe. The differences between the rRNA genes of S. japonicus and S. pombe, however, are much smaller than the intrageneric differences within the rDNA sequences of other yeast genera. Therefore, subdivision of fission yeasts into the genera Schizosaccharomyces and Hasegawaea does not to seem to be justified. The sequence has been deposited in the EMBL data bank under the accession number Z 32848.
José Antonio Suárez-lepe - One of the best experts on this subject based on the ideXlab platform.
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Schizosaccharomyces pombe: A Promising Biotechnology for Modulating Wine Composition
Fermentation, 2018Co-Authors: Iris Loira, Felipe Palomero, Antonio Morata, Carmen González, José Antonio Suárez-lepeAbstract:There are numerous yeast species related to wine making, particularly non-Saccharomyces, that deserve special attention due to the great potential they have when it comes to making certain changes in the composition of the wine. Among them, Schizosaccharomyces pombe stands out for its particular metabolism that gives it certain abilities such as regulating the acidity of wine through maloalcoholic fermentation. In addition, this species is characterized by favouring the formation of stable pigments in wine and releasing large quantities of polysaccharides during ageing on lees. Moreover, its urease activity and its competition for malic acid with lactic acid bacteria make it a safety tool by limiting the formation of ethyl carbamate and biogenic amines in wine. However, it also has certain disadvantages such as its low fermentation speed or the development of undesirable flavours and aromas. In this chapter, the main oenological uses of Schizosaccharomyces pombe that have been proposed in recent years will be reviewed and discussed.
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Schizosaccharomyces pombe: A Promising Biotechnology to Modulate Wine Composition
2018Co-Authors: Iris Loira, Felipe Palomero, Antonio Morata, Carmen González, José Antonio Suárez-lepeAbstract:There are numerous yeast species related to wine making, particularly non-Saccharomyces, that deserve special attention due to the great potential they have when it comes to making certain changes in the composition of the wine. Among them, Schizosaccharomyces pombe stands out for its particular metabolism that gives it certain abilities such as regulating the acidity of wine through maloalcoholic fermentation. In addition, this species is characterized by favouring the formation of stable pigments in the wine and releasing large quantities of polysaccharides during ageing on lees. Moreover, its urease activity and its competition for malic acid with lactic acid bacteria make it a safety tool by limiting the formation of ethyl carbamate and biogenic amines in wine. However, it also has certain disadvantages such as its low fermentation speed or the development of undesirable flavours and aromas. In this chapter, the main oenological uses of Schizosaccharomyces pombe that have been proposed in the last years will be reviewed and discussed.
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Use of Schizosaccharomyces strains for wine fermentation-Effect on the wine composition and food safety.
International journal of food microbiology, 2016Co-Authors: A.e. Mylona, Felipe Palomero, Santiago Benito, Antonio Morata, Fernando Calderón, J.m. Del Fresno, Iris Loira, M.a. Bañuelos, José Antonio Suárez-lepeAbstract:Schizosaccharomyces was initially considered as a spoilage yeast because of the production of undesirable metabolites such as acetic acid, hydrogen sulfide, or acetaldehyde, but it currently seems to be of great value in enology.o ced Nevertheless, Schizosaccharomyces can reduce all of the malic acid in must, leading to malolactic fermentation. Malolactic fermentation is a highly complicated process in enology and leads to a higher concentration of biogenic amines, so the use of Schizosaccharomyces pombe can be an excellent tool for assuring wine safety. Schizosaccharomyces also has much more potential than only reducing the malic acid content, such as increasing the level of pyruvic acid and thus the vinylphenolic pyranoanthocyanin content. Until now, few commercial strains have been available and little research on the selection of appropriate yeast strains with such potential has been conducted. In this study, selected and wild Sc. pombe strains were used along with a Saccharomyces cerevisiae strain to ferment red grape must. The results showed significant differences in several parameters including non-volatile and volatile compounds, anthocyanins, biogenic amines and sensory parameters.
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Selection of appropriate Schizosaccharomyces strains for winemaking
Food microbiology, 2014Co-Authors: Santiago Benito, Felipe Palomero, D. Palmero, Fernando Calderón, José Antonio Suárez-lepeAbstract:This paper describes the selection of Schizosaccharomyces yeasts with adequate oenological suitability and high capacity for the degradation of malic acid. Despite the almost non-existent number of commercial strains, the use of this yeast genus has recently been recommended by the International Organisation of Vine and Wine (OIV, in French). Thus, in the present study, a large number of Schizosaccharomyces strains were isolated using a selective differential medium. Initially, classic parameters of oenological interest for the use of fermentative strains of Saccharomyces cerevisiae (the most frequently used type of yeast) were assessed. Only five strains of moderate acetic acid production lower than 0.4 g/L were obtained at the end of fermentation. Other, more specific features of this yeast genus' physiology were also studied, including urease activity and the production of pyruvic acid and glycerol. Finally, oenological suitability was determined by comparing selected strains with other Schizosaccharomyces reference and S cerevisiae control strains. Schizosaccharomyces strains produced 80% less urea content, four times higher pyruvic acid levels and 1 g higher glycerol contents than the Saccharomyces reference strains. The results confirmed that it is possible to perform selective processes on microorganisms from the genus Schizosaccharomyces using methodology developed in this work to obtain strains of industrial interest.
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Physiological features of Schizosaccharomyces pombe of interest in making of white wines
European Food Research and Technology, 2013Co-Authors: Samantha Benito, F. Calderón, Alex Morata, Felipe Palomero, D. Palmero, José Antonio Suárez-lepeAbstract:This work studies the physiology of Schizosaccharomyces pombe strain 938 in the production of white wine with high malic acid levels as the sole fermentative yeast, as well as in mixed and sequential fermentations with Saccharomyces cerevisiae Cru Blanc . The induction of controlled maloalcoholic fermentation through the use of Schizosaccharomyces spp. is now being viewed with much interest. The acetic, malic and pyruvic acid concentrations, relative density and pH of the musts were measured over the entire fermentation period. In all fermentations in which Schizo. pombe 938 was involved, nearly all the malic acid was consumed and moderate acetic concentrations produced. The urea content and alcohol level of these wines were notably lower than in those made with Sacch. cerevisiae Cru Blanc alone. The pyruvic acid concentration was significantly higher in Schizo. pombe fermentations. The sensorial properties of the different final wines varied widely.
