title: Sexual co-flocculation by heterothallic cells of the fission yeast Schizosaccharomyces pombe modulated by medium constituents.
abstract: Novel simple synthetic media for inducing sexual co-flocculation in a short time after mixing heterothallic fission-yeast (Schizosaccharomyces pombe) cells of h- and h+ were devised; The most effective of these, mannose synthetic medium (MSM), contains 0.4% mannose as a carbon source in addition to galactose, KH2PO4 (pH4.0) and 4 vitamins. The addition of galactose to the medium suppressed the asexual self-flocculation but rather promoted the sexual co-flocculation. By transferring and mixing h- and h+ cells grown in malt-extract broth plus galactose into MSM, these heterothallic strains were revealed to be sexually ready through a long period of the log to stationary phases. Furthermore, a variety of C sources and NH4Cl at various concentrations in various media were examined for their effects upon sexual co-flocculation, conjugation and sporulation; it was found that the sugar concentration strictly affected the progress of the sequence of sexual reproduction at 26 degrees C but not 30 degrees C and that sexual co-flocculation of the heterothallic strains was induced only under lower concentrations of C and N source than that for the homothallic one.
authors.affiliation: Gifu Pharmaceutical University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Miyata
authors.forename: H
authors.initials: H
authors.lastname: Doi
authors.forename: H
authors.initials: H
authors.lastname: Miyata
authors.forename: B F
authors.initials: BF
authors.lastname: Johnson
mesh_terms: D000643:Ammonium Chloride / Q000378:metabolism; D015169:Colony Count, Microbial; D003227:Conjugation, Genetic; D003470:Culture Media / Q000378:metabolism*; D002523:Edible Grain / Q000378:metabolism; D005690:Galactose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D008358:Mannose / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D017680:Potassium Compounds / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D013170:Spores / Q000254:growth & development; D013696:Temperature; D014815:Vitamins / Q000378:metabolism
chemical_list: D003470:Culture Media; D010710:Phosphates; D017680:Potassium Compounds; D014815:Vitamins; D000643:Ammonium Chloride; C013216:potassium phosphate; D005947:Glucose; D008358:Mannose; D005690:Galactose