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Spaller T, Groth M, Glöckner G, Winckler T. TRE5-A retrotransposition profiling reveals putative RNA polymerase III transcription complex binding sites on the Dictyostelium extrachromosomal rDNA element. PLoS One 2017; 12:e0175729. [PMID: 28406973 PMCID: PMC5391098 DOI: 10.1371/journal.pone.0175729] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 03/30/2017] [Indexed: 11/28/2022] Open
Abstract
The amoeba Dictyostelium discoideum has a haploid genome in which two thirds of the DNA encodes proteins. Consequently, the space available for selfish mobile elements to expand without excess damage to the host genome is limited. The non-long terminal repeat retrotransposon TRE5-A maintains an active population in the D. discoideum genome and apparently adapted to this gene-dense environment by targeting positions ~47 bp upstream of tRNA genes that are devoid of protein-coding regions. Because only ~24% of tRNA genes are associated with a TRE5-A element in the reference genome, we evaluated whether TRE5-A retrotransposition is limited to this subset of tRNA genes. We determined that a tagged TRE5-A element (TRE5-Absr) integrated at 384 of 405 tRNA genes, suggesting that expansion of the current natural TRE5-A population is not limited by the availability of targets. We further observed that TRE5-Absr targets the ribosomal 5S gene on the multicopy extrachromosomal DNA element that carries the ribosomal RNA genes, indicating that TRE5-A integration may extend to the entire RNA polymerase III (Pol III) transcriptome. We determined that both natural TRE5-A and cloned TRE5-Absr retrotranspose to locations on the extrachromosomal rDNA element that contain tRNA gene-typical A/B box promoter motifs without displaying any other tRNA gene context. Based on previous data suggesting that TRE5-A targets tRNA genes by locating Pol III transcription complexes, we propose that A/B box loci reflect Pol III transcription complex assembly sites that possess a function in the biology of the extrachromosomal rDNA element.
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MESH Headings
- Binding Sites
- DNA, Protozoan/chemistry
- DNA, Protozoan/genetics
- DNA, Protozoan/metabolism
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- DNA, Ribosomal/metabolism
- Dictyostelium/genetics
- Promoter Regions, Genetic
- Protozoan Proteins/metabolism
- RNA Polymerase III/metabolism
- RNA, Ribosomal, 5S/genetics
- RNA, Transfer/genetics
- Retroelements/genetics
- Transcription, Genetic
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Affiliation(s)
- Thomas Spaller
- Pharmaceutical Biology, Institute of Pharmacy, University of Jena, Jena, Germany
| | - Marco Groth
- Core Facility DNA Sequencing, Leibniz Institute for Age Research–Fritz Lipmann Institute, Jena, Germany
| | - Gernot Glöckner
- Institute for Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany
| | - Thomas Winckler
- Pharmaceutical Biology, Institute of Pharmacy, University of Jena, Jena, Germany
- * E-mail:
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2
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Sucgang R, Chen G, Liu W, Lindsay R, Lu J, Muzny D, Shaulsky G, Loomis W, Gibbs R, Kuspa A. Sequence and structure of the extrachromosomal palindrome encoding the ribosomal RNA genes in Dictyostelium. Nucleic Acids Res 2003; 31:2361-8. [PMID: 12711681 PMCID: PMC154234 DOI: 10.1093/nar/gkg348] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ribosomal RNAs (rRNAs) are encoded by multicopy families of identical genes. In Dictyostelium and other protists, the rDNA is carried on extrachromosomal palindromic elements that comprise up to 20% of the nuclear DNA. We present the sequence of the 88 kb Dictyostelium rDNA element, noting that the rRNA genes are likely to be the only transcribed regions. By interrogating a library of ordered YAC clones, we provide evidence for a chromosomal copy of the rDNA on chromosome 4. This locus may provide master copies for the stable transmission of the extrachromosomal elements. The extrachromosomal elements were also found to form chromosome-sized clusters of DNA within nuclei of nocodazole-treated cells arrested in mitosis. These clusters resemble true chromosomes and may allow the efficient segregation of the rDNA during mitosis. These rDNA clusters may also explain the cytological observations of a seventh chromosome in this organism.
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Affiliation(s)
- Richard Sucgang
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
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Dictyostelium amoebae lacking an F-box protein form spores rather than stalk in chimeras with wild type. Proc Natl Acad Sci U S A 2000. [PMID: 10725352 PMCID: PMC16232 DOI: 10.1073/pnas.050005097] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Using a selection for Dictyostelium mutants that preferentially form spores, we have recovered a mutant called CheaterA. In chimeras with isogenic wild-type cells, the CheaterA mutant preferentially forms viable spores rather than inviable stalk cells. The mutant causes wild-type cells that have begun to express spore-specific genes to accumulate in the prestalk compartment of the developing organism. In the wild-type cells, the chtA transcript is absent in growing cells and appears early in development. No transcript was detected in the mutant by Northern blot. The chtA gene codes for a protein with an F-box and WD40 domains. This class of protein usually forms part of an Skp1, cullin, F-box (SCF) complex that targets specific protein substrates for ubiquitination and degradation.
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4
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Plasmid maintenance functions encoded on Dictyostelium discoideum nuclear plasmid Ddp1. Mol Cell Biol 1994. [PMID: 8065344 DOI: 10.1128/mcb.14.9.6117] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
All of the plasmid-carried genes expressed during vegetative growth are essential for long-term maintenance of plasmid Ddp1 in the nucleus of Dictyostelium discoideum. Deletion of Ddp1 genes expressed only during development had no detectable effect on plasmid maintenance. Deletion of vegetatively expressed genes, either singly or in pairs, resulted in (i) a rapid loss of plasmid from cells grown in the absence of selection for plasmid retention, (ii) variation in the proportion of monomer to multimer forms of the plasmid molecules, and/or (iii) abnormalities in plasmid copy number. At least two plasmid-encoded gene products influence patterns of expression of plasmid genes.
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Hughes JE, Kiyosawa H, Welker DL. Plasmid maintenance functions encoded on Dictyostelium discoideum nuclear plasmid Ddp1. Mol Cell Biol 1994; 14:6117-24. [PMID: 8065344 PMCID: PMC359138 DOI: 10.1128/mcb.14.9.6117-6124.1994] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
All of the plasmid-carried genes expressed during vegetative growth are essential for long-term maintenance of plasmid Ddp1 in the nucleus of Dictyostelium discoideum. Deletion of Ddp1 genes expressed only during development had no detectable effect on plasmid maintenance. Deletion of vegetatively expressed genes, either singly or in pairs, resulted in (i) a rapid loss of plasmid from cells grown in the absence of selection for plasmid retention, (ii) variation in the proportion of monomer to multimer forms of the plasmid molecules, and/or (iii) abnormalities in plasmid copy number. At least two plasmid-encoded gene products influence patterns of expression of plasmid genes.
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Affiliation(s)
- J E Hughes
- Department of Biology, Utah State University, Logan 84322-5500
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Kalpaxis D, Zündorf I, Werner H, Reindl N, Boy-Marcotte E, Jacquet M, Dingermann T. Positive selection for Dictyostelium discoideum mutants lacking UMP synthase activity based on resistance to 5-fluoroorotic acid. MOLECULAR & GENERAL GENETICS : MGG 1991; 225:492-500. [PMID: 2017144 DOI: 10.1007/bf00261692] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In the cellular slime mould Dictyostelium discoideum the two enzymatic activities of the pyrimidine pathway, orotidine-5'-phosphate decarboxylase (EC 4.1.1.23; OMPdecase) and orotate phosphoribosyl transferase (EC 2.4.2.10; OPRTase), are encoded by a single gene (DdPYR5-6). As in higher eukaryotes the bifunctional enzyme is referred to as UMP synthase. Here we present a method that allows efficient generation and selection of mutants lacking UMP synthase. D. discoideum cells are transformed with either of two different types of plasmids. One plasmid type contains no sequences homologous to the UMP synthase gene whereas the other type contains at least parts of this gene. UMP synthase- mutants, which were positively selected for in the presence of 5-fluoroorotic acid (5-FOA), were obtained with both plasmids. However, mutation rates were at least one order of magnitude higher if plasmids containing various portions of the UMP synthase gene were used as opposed to plasmids that lack any homology to the UMP synthase locus. Several mutant strains were extensively characterized. These strains lack OMPdecase activity and exhibit in addition to 5-FOA resistance a ura- phenotype. All mutants carry UMP synthase loci with deletions of various extents but integration of transforming plasmids was not detected. This efficient generation of 5-FOA resistance is part of a proposed complex selection scheme which allows multiple rounds of transformation of D. discoideum.
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Affiliation(s)
- D Kalpaxis
- Institut für Biochemie der Medizinischen Fakultät, Universität Erlangen-Nürnberg, Federal Republic of Germany
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Jensen SL, Ashktorab H, Hughes JE, Welker DL. Gene amplification associated with the dominant cob-354 cobalt resistance trait in Dictyostelium discoideum. MOLECULAR & GENERAL GENETICS : MGG 1989; 220:25-32. [PMID: 2608027 DOI: 10.1007/bf00260851] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A DNA amplification is correlated with the dominant, unstable cob-354 cobalt resistance trait in the cellular slime mold, Dictyostelium discoideum. The amplified DNA is present as about 50 copies of an extrachromosomal element. Cells grown under nonselective conditions in the absence of cobalt ions lose both the cobalt resistance trait and all extrachromosomal copies of the amplified DNA. The amplified DNA is transferrable to new genetic backgrounds by parasexual genetic crosses. These results explain the inability to map the cob-354 trait to a linkage group. The chromosomal origin of the amplified DNA is group III or VI. Thus the resistance trait appears to be independent of the previously known cobalt resistance locus, cobA, which maps to group VII. A developmental defect involving the production of multiply-tipped aggregates that do not complete fruiting body formation also is correlated with the presence of the amplified DNA.
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Affiliation(s)
- S L Jensen
- Department of Biology, Utah State University, Logan 84322-5500
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8
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The cyclic nucleotide phosphodiesterase gene of Dictyostelium discoideum utilizes alternate promoters and splicing for the synthesis of multiple mRNAs. Mol Cell Biol 1989. [PMID: 2779573 DOI: 10.1128/mcb.9.9.3938] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The cyclic nucleotide phosphodiesterase (phosphodiesterase) gene plays essential roles in the development of Dictyostelium discoideum during cellular aggregation and postaggregation morphogenesis. Genomic clones spanning the gene were isolated and used to determine the sequence and structure of the phosphodiesterase gene. We found an unusually complex organization for a gene of D. discoideum. Two transcripts of 2.4 and 1.9 kilobases (kb) were synthesized from start sites separated by 1.1 kb. A developmentally regulated promoter was utilized for the 2.4-kb mRNA, and a constitutive promoter regulated synthesis of the 1.9-kb transcript. The gene was found to be divided into four exons that are alternately spliced to give rise to the two mRNAs. The precursor of the 2.4-kb mRNA contained a 2.3-kb intron, whereas the precursor of the constitutive transcript was synthesized with a 1.7-kb intron. The two transcripts contained identical protein-coding regions and 400-nucleotide 3' untranslated sequences. The 2.4-kb developmentally regulated mRNA was distinguished by a long 5' untranslated leader of 666 nucleotides. The complex structure of the gene may allow multiple levels of control of the expression of the phosphodiesterase during development.
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9
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Podgorski GJ, Franke J, Faure M, Kessin RH. The cyclic nucleotide phosphodiesterase gene of Dictyostelium discoideum utilizes alternate promoters and splicing for the synthesis of multiple mRNAs. Mol Cell Biol 1989; 9:3938-50. [PMID: 2779573 PMCID: PMC362456 DOI: 10.1128/mcb.9.9.3938-3950.1989] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The cyclic nucleotide phosphodiesterase (phosphodiesterase) gene plays essential roles in the development of Dictyostelium discoideum during cellular aggregation and postaggregation morphogenesis. Genomic clones spanning the gene were isolated and used to determine the sequence and structure of the phosphodiesterase gene. We found an unusually complex organization for a gene of D. discoideum. Two transcripts of 2.4 and 1.9 kilobases (kb) were synthesized from start sites separated by 1.1 kb. A developmentally regulated promoter was utilized for the 2.4-kb mRNA, and a constitutive promoter regulated synthesis of the 1.9-kb transcript. The gene was found to be divided into four exons that are alternately spliced to give rise to the two mRNAs. The precursor of the 2.4-kb mRNA contained a 2.3-kb intron, whereas the precursor of the constitutive transcript was synthesized with a 1.7-kb intron. The two transcripts contained identical protein-coding regions and 400-nucleotide 3' untranslated sequences. The 2.4-kb developmentally regulated mRNA was distinguished by a long 5' untranslated leader of 666 nucleotides. The complex structure of the gene may allow multiple levels of control of the expression of the phosphodiesterase during development.
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Affiliation(s)
- G J Podgorski
- Department of Anatomy and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York 10032
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10
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Fisher PR, Merkl R, Gerisch G. Quantitative analysis of cell motility and chemotaxis in Dictyostelium discoideum by using an image processing system and a novel chemotaxis chamber providing stationary chemical gradients. J Cell Biol 1989; 108:973-84. [PMID: 2537839 PMCID: PMC2115405 DOI: 10.1083/jcb.108.3.973] [Citation(s) in RCA: 140] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
An image processing system was programmed to automatically track and digitize the movement of amebae under phase-contrast microscopy. The amebae moved in a novel chemotaxis chamber designed to provide stable linear attractant gradients in a thin agarose gel. The gradients were established by pumping attractant and buffer solutions through semipermeable hollow fibers embedded in the agarose gel. Gradients were established within 30 min and shown to be stable for at least a further 90 min. By using this system it is possible to collect detailed data on the movement of large numbers of individual amebae in defined attractant gradients. We used the system to study motility and chemotaxis by a score of Dictyostelium discoideum wild-type and mutant strains, including "streamer" mutants which are generally regarded as being altered in chemotaxis. None of the mutants were altered in chemotaxis in the optimal cAMP gradient of 25 nM/mm, with a midpoint of 25 nM. The dependence of chemotaxis on cAMP concentration, gradient steepness, and temporal changes in the gradient were investigated. We also analyzed the relationship between turning behavior and the direction of travel during chemotaxis in stable gradients. The results suggest that during chemotaxis D. discoideum amebae spatially integrate information about local increases in cAMP concentration at various points on the cell surface.
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Affiliation(s)
- P R Fisher
- Max Planck Institut für Biochemie, Martinsried bei München, Federal Republic of Germany
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Welker DL. The discoidin I gene family of Dictyostelium discoideum is linked to genes regulating its expression. Genetics 1988; 119:571-8. [PMID: 3402731 PMCID: PMC1203443 DOI: 10.1093/genetics/119.3.571] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The discoidin I protein has been studied extensively as a marker of early development in the cellular slime mold Dictyostelium discoideum. However, like most other developmentally regulated proteins in this system, no reliable information was available on the linkage of the discoidin genes to other known genes. Analysis of the linkage of the discoidin I genes by use of restriction fragment length polymorphisms revealed that all three discoidin I genes as well as a pseudogene are located on linkage group II. This evidence is consistent with the discoidin I genes forming a gene cluster that may be under the control of a single regulatory element. The discoidin I genes are linked to three genetic loci (disA, motA, daxA) that affect the expression of the discoidin I protein. Linkage of the gene family members to regulatory loci may be important in the coordinate maintenance of the gene family and regulatory loci. A duplication affecting the entire discoidin gene family is also linked to group II; this appears to be a small tandem duplication. This duplication was mapped using a DNA polymorphism generated by insertion of the Tdd-3 mobile genetic element into a Tdd-2 element flanking the gamma gene. A probe for Tdd-2 identified a restriction fragment length polymorphism in strain AX3K that was consistent with generation by a previously proposed Tdd-3 insertion event. A putative duplication or rearrangement of a second Tdd-2 element on linkage group IV of strain AX3K was also identified. This is the first linkage information available for mobile genetic elements in D. discoideum.
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Affiliation(s)
- D L Welker
- Department of Biology, Utah State University, Logan 84322-5500
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12
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Dingermann T, Amon E, Williams KL, Welker DL. Chromosomal mapping of tRNA genes from Dictyostelium discoideum. MOLECULAR & GENERAL GENETICS : MGG 1987; 207:176-87. [PMID: 3474495 DOI: 10.1007/bf00331507] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Different wild-type isolates of Dictyostelium discoideum exhibit extensive polymorphism in the length of restriction fragments carrying tRNA genes. These size differences were used to study the organisation of two tRNA gene families which encode a tRNA Val(GUU) and a tRNA Val(GUA) gene. The method used involved a combination of classical D. discoideum parasexual genetics and molecular genetics. The tRNA genes were mapped to specific linkage groups (chromosomes) by correlating the presence of polymorphic DNA bands that hybridized with the tRNA gene probes with the presence of genetic markers for those linkage groups. These analyses established that both of the tRNA gene families are dispersed among sites on several of the chromosomes. Information of nine tRNA Val(GUU) genes from the wild-type isolate NC4 was obtained: three map to linkage group I (C, E, F), two map to linkage group II (D, I), one maps to linkage group IV (G), one, which corresponds to the cloned gene, maps to either linkage group III or VI (B), and two map to one of linkage groups III, VI or VII (A, H). Six tRNA Val(GUA) genes from the NC4 isolate were mapped: one to linkage group I (D), two to linkage group III, VI or VII (B, C) and three to linkage group VII or III (A, E, F).
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