title: A prespore gene, Dd31, expressed during culmination of Dictyostelium discoideum.
abstract: During culmination of Dictyostelium fruiting bodies, prespore and prestalk cells undergo terminal differentiation to form spores and a cellular stalk. A genomic fragment was isolated by random cloning that hybridizes to a 1.4-kb mRNA present during culmination. Cell type separations at culmination showed that the mRNA is present in prespore cells and spores, but not in prestalk or stalk cells. After genomic mapping, an additional 3 kb of DNA surrounding the original 1-kb fragment was cloned. The gene was sequenced and named Dd31 after the size of the predicted protein product in kilodaltons. Accumulation of Dd31 mRNA occurs immediately prior to sporulation. Addition of 20 mM 8-Br-cAMP to cells dissociated from Mexican hat stage culminants induced sporulation and the accumulation of Dd31 mRNA, while 20 mM cAMP did not. Dd31 mRNA does not accumulate in the homeotic mutant stalky in which prespore cells are converted to stalk cells rather than spores. Characterization of Dd31 extends the known temporal dependent sequence of molecular differentiations to sporulation.
authors.affiliation: Department of Biology, University of California, San Diego, La Jolla 92093-0322.
authors.forename: D L
authors.initials: DL
authors.lastname: Richardson
authors.forename: C B
authors.initials: CB
authors.lastname: Hong
authors.forename: W F
authors.initials: WF
authors.lastname: Loomis
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002448:Cell Adhesion; D002454:Cell Differentiation; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000235:genetics; D004023:Dictyostelium / Q000166:cytology / Q000235:genetics*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D015800:Protozoan Proteins; D012331:RNA, Fungal / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D015183:Restriction Mapping; D012995:Solubility; D013172:Spores, Fungal
chemical_list: D004271:DNA, Fungal; D005656:Fungal Proteins; D009841:Oligonucleotides; D015800:Protozoan Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; C068128:SPIA protein, Dictyostelium discoideum