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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http://dx.doi.org/10.1093/femsyr/fox045 | DOI Listing |
Mol Phylogenet Evol
January 2025
Department of Ecology and Evolutionary Biology and University of Michigan Herbarium, University of Michigan, Ann Arbor, MI 48109, USA.
Lorchels, also known as false morels (Gyromitra sensu lato), are iconic due to their brain-shaped mushrooms and production of gyromitrin, a deadly mycotoxin. Molecular phylogenetic studies have hitherto failed to resolve deep-branching relationships in the lorchel family, Discinaceae, hampering our ability to settle longstanding taxonomic debates and to reconstruct the evolution of toxin production. We generated 75 draft genomes from cultures and ascomata (some collected as early as 1960), conducted phylogenomic analyses using 1542 single-copy orthologs to infer the early evolutionary history of lorchels, and identified genomic signatures of trophic mode and mating-type loci to better understand lorchel ecology and reproductive biology.
View Article and Find Full Text PDFMycoscience
June 2024
Faculty of Agriculture, Tottori University.
In this study, white jelly mushrooms that were collected in Tottori Prefecture, Japan, were identified as by phylogenetic analysis of the rDNA-ITS region. Fluorescent microscopic analysis using 4',6-diamidino-2-phenylindole staining to visualize the nuclei in each cell revealed that basidiospores isolated from the fruiting body were monokaryotic. Furthermore, monokaryotic yeasts were germinated from these basidiospores and the resulting crossed mycelium was dikaryotic and bore clamp cells, suggesting a heterothallic lifecycle for this species.
View Article and Find Full Text PDFFront Plant Sci
October 2024
Institute for Breeding Research on Fruit Crops, Julius Kühn-Institute (JKI) - Federal Research Centre for Cultivated Plants, Dresden, Germany.
Int J Food Microbiol
December 2024
Departamento de Ciencias Biomédicas (Área de Microbiología), Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s/n, 06006 Badajoz, Spain. Electronic address:
Mycologia
September 2024
Laboratory of Mycology and Phytopathology, All-Russian Institute of Plant Protection, shosse Podbelskogo 3, Saint Petersburg 196608, Russia.
is a large genus within Pleosporaceae and consists of fungi that have up to recently been considered to be 15 separate genera, including . The majority of species after incorporation into were placed in three sections: , and . In this study, phylogeny of 26 reference strains of 22 species and 20 Russian -like isolates was recovered.
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