title: The wacA gene of Dictyostelium discoideum is a developmentally regulated member of the MIP family.
abstract: We isolated a cDNA from Dictyostelium discoideum that encodes a 30 kDa protein with significant similarity to members of the major intrinsic protein (MIP) family of membrane transporters. The most closely related protein in the public data bases is an aquaporin from Cicadella viridis which shows 34% identity. The cDNA was used to isolate and characterize genomic fragments carrying the Dictyostelium gene which we named wacA. Genomic probes were used to recognize wacA mRNA isolated at various stages of development. The results showed that the gene is developmentally regulated such that the mRNA first appears at 12 h of development and is retained throughout the remainder of development. In situ hybridization of whole mounts prepared at 15 h of development showed that wacA mRNA accumulates exclusively in prespore cells and is absent from prestalk cells. Although wacA expression is prespore specific, disruption of the gene by homologous recombination did not result in observable alterations in the formation of spores or their resistance to osmotic challenges.
authors.affiliation: Department of Biology, University of California at San Diego, La Jolla 92093-0322, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Flick
authors.forename: G
authors.initials: G
authors.lastname: Shaulsky
authors.forename: W F
authors.initials: WF
authors.lastname: Loomis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D020346:Aquaporins; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D015342:DNA Probes / Q000235:genetics; D004023:Dictyostelium / Q000235:genetics* / Q000254:growth & development; D005136:Eye Proteins / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D017125:Genes, Protozoan; D017403:In Situ Hybridization; D007313:Insecta / Q000235:genetics; D008562:Membrane Glycoproteins; D008969:Molecular Sequence Data; D009997:Osmotic Pressure; D018272:Porins / Q000235:genetics*; D015800:Protozoan Proteins; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D017386:Sequence Homology, Amino Acid; D013172:Spores, Fungal / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D020346:Aquaporins; D015342:DNA Probes; D005136:Eye Proteins; D008562:Membrane Glycoproteins; D018272:Porins; D015800:Protozoan Proteins; D012333:RNA, Messenger; C108521:WacA protein, Dictyostelium discoideum; C030328:aquaporin 0