title: Evidence for an induced plasma membrane mating receptor in the myxomycete Didymium iridis.
abstract: Haploid myxamoeboid mating types, CR5-11A11 and HON 1-2A1, of the acellular myxomycete Didymium iridis, were isolated and grown in liquid culture. Previously it has been postulated that a molecule, possibly a hormone, is responsible for the induction of mating competency through receptor site synthesis. The intention of this study was to isolate the molecule and to determine its mode of action. Experiments were designed in order to learn whether it acts only upon the cells which produce it (self-induction) or does it have an effect only on opposite mating types (cross-induction). It was found that plasmodia can only form on solid media, although zygotes are readily formed in liquid media. Moreover, competency of cells to fuse, or to form receptors required that they be haploid and in a specific phase of the cell cycle, namely G1 of interphase. The use of high pressure liquid chromatography techniques was also employed in order to investigate the inducer molecule. It was demonstrated that the inducer molecule was similarly produced by both mating types, and its production was essentially paralleled by cell numbers. It was also discovered that mating competency is self-induced and these results are discussed.
authors.affiliation: Department of Biology, Youngstown State University, Ohio 44555.
authors.forename: J J
authors.initials: JJ
authors.lastname: Yemma
authors.forename: K M
authors.initials: KM
authors.lastname: Stroh
mesh_terms: D002462:Cell Membrane / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004271:DNA, Fungal / Q000032:analysis; D009235:Myxomycetes / Q000032:analysis* / Q000235:genetics / Q000254:growth & development; D011956:Receptors, Cell Surface / Q000032:analysis*; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide; D014157:Transcription Factors
chemical_list: D004271:DNA, Fungal; D011956:Receptors, Cell Surface; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide; D014157:Transcription Factors