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At least 19 recordsLinked to original sources
PubMed2006

Integration into the phage attachment site, attB, impairs multicellular differentiation in Stigmatella aurantiaca.

Stigmatella aurantiaca displays a complex developmental life cycle in response to starvation conditions that results in the formation of tree-like fruiting bodies capable of producing spores. The phage Mx8, first isolated from the close relative Myxococcus xanthus, is unable to infect S. aurantiaca cells and integrate into the genome. However, plasmids containing Mx8 fragments encoding the integrase and attP are able to integrate at the attB locus in the S. aurantiaca genome by site-specific recombination. After recombination between attP and attB, the S. aurantiaca cells were incapable of building normal fruiting bodies but formed clumps and fungus-like structures characteristic of intermediate stages of development displayed by the wild type. We identified two tRNA genes, trnD and trnV, encoding tRNA(Asp) and tRNA(Val), respectively, composing an operon at the attB locus of S. aurantiaca. Integration of attP-containing plasmids resulted in the incorporation of the t(Mx8) terminator sequence, in addition to a short sequence of Mx8 DNA downstream of trnD. The integrant was unable to process the trnD transcript at the normal 3' processing site and displayed a lower level of expression of the trnVD operon. In addition, several developmentally regulated proteins were no longer produced in mutants following insertion at the attB locus. We hypothesize that the integration of the t(Mx8) terminator sequence results in reduced levels of mature tRNA(Asp) and tRNA(Val) and that altered protein production during development is thereby responsible for the observed phenotype. The trnVD locus thus defines a new developmental checkpoint for Stigmatella aurantiaca.

Attachment Sites, Microbiological↗
PubMed1987

Biosynthesis and structure of stable branched RNA covalently linked to the 5' end of multicopy single-stranded DNA of Stigmatella aurantiaca.

Stigmatella aurantiaca, a gram-negative bacterium, contains approximately 500 copies per cell of a short single-stranded linear DNA (multicopy single-stranded DNA: msDNA). This DNA is attached to a branched RNA (msdRNA) by its 5' end. The entire sequence of msdRNA was determined and found to consist of 76 bases. The msDNA is linked at the 19th G residue of msdRNA by a 2', 5' phosphodiester linkage. The coding region for msdRNA (msr) is located downstream of the coding region for msDNA (msd). These coding regions exist in opposite orientation with respect to each other and overlap by 8 bases at their 3' ends. Biosynthesis of RNA-linked msDNA was characterized and mechanisms of synthesis are proposed.

Base Sequence↗
PubMed1993

Purification and characterization of SP21, a development-specific protein of the myxobacterium Stigmatella aurantiaca.

Stigmatella aurantiaca is a gram-negative bacterium with a complex life cycle, including cellular aggregation resulting in the formation of a characteristic three-dimensional structure, the so-called fruiting body. During fruiting and upon chemical induction of sporulation, a major development-specific protein, SP21, is synthesized. SP21 was purified to homogeneity from the membranous fraction of chemically induced spores. Expression of SP21 was studied with an antiserum raised against the purified protein.

Amino Acid Sequence↗
PubMed1992

Size and stability of the genomes of the myxobacteria Stigmatella aurantiaca and Stigmatella erecta.

Genomic DNA of Stigmatella aurantiaca DW 4/3.1 was restricted with the rare-cutting endonucleases AseI and SpeI. The restriction pattern derived is composed of 33 AseI and 25 SpeI fragments, whose total size amounts to approximately 9,350 kbp. Genomic fingerprint analysis of chromosomal DNA from several S. aurantiaca isolates further revealed five completely different SpeI and AseI fingerprints and one distinct fingerprint for Stigmatella erecta. In addition, minor variations between the genome sizes of these isolates were observed.

Chromosome Mapping↗
PubMed1999

Intercellular signalling in Stigmatella aurantiaca.

The myxobacterium Stigmatella aurantiaca is a prokaryotic model used to study intercellular signalling and the genetic determination of morphogenesis. Signalling factors and genes required for the generation of the elaborate multicellular fruiting body are to be identified. Recently, the structure of stigmolone, which is the pheromone necessary for fruiting body formation, was elucidated, and genes involved in development were characterised. Progress has also been made in the genetic accessibility of S. aurantiaca.

Alkanes↗
PubMed1987

Branched RNA covalently linked to the 5' end of a single-stranded DNA in Stigmatella aurantiaca: structure of msDNA.

Stigmatella aurantiaca is a gliding, gram-negative bacterium that shows a spectacular fruiting body formation upon starvation of nutrient. This bacterium was found to contain approximately 500 copies per cell of a short single-stranded linear DNA (multicopy single-stranded DNA: msDNA). The primary structure of msDNA was determined and found to consist of 162 or 163 deoxyribonucleotides. Its unique chromosomal gene was cloned and sequenced. The msDNA was found to be attached to a branched RNA by its 5' end. Structural analysis of the branched RNA revealed that it consists of a triribonucleotide, 5'A-G-(C or U)3', and that msDNA is branched out from the 2' position of the rG residue forming a 2', 5' phosphodiester linkage with the dC residue at the 5' end of msDNA.

Base Sequence↗
PubMed1998

fbfB, a gene encoding a putative galactose oxidase, is involved in Stigmatella aurantiaca fruiting body formation.

Stigmatella aurantiaca is a gram-negative bacterium which forms, under conditions of starvation in a multicellular process, characteristic three-dimensional structures: the fruiting bodies. For studying this complex process, mutants impaired in fruiting body formation have been induced by transposon insertion with a Tn5-derived transposon. The gene affected (fbfB) in one of the mutants (AP182) was studied further. Inactivation of fbfB results in mutants which form only clumps during starvation instead of wild-type fruiting bodies. This mutant phenotype can be partially rescued, if cells of mutants impaired in fbfB function are mixed with those of some independent mutants defective in fruiting before starvation. The fbfB gene is expressed about 14 h after induction of fruiting body formation as determined by measuring beta-galactosidase activity in a merodiploid strain harboring the wild-type gene and an fbfB-delta trp-lacZ fusion gene or by Northern (RNA) analysis with the Rhodobacter capsulatus pufBA fragment fused to fbfB as an indicator. The predicted polypeptide FbfB has a molecular mass of 57.8 kDa and shows a significant homology to the galactose oxidase (GaoA) of the fungus Dactylium dendroides. Galactose oxidase catalyzes the oxidation of galactose and primary alcohols to the corresponding aldehydes.

Amino Acid Sequence↗
PubMed1978

Light-stimulated morphogenesis in the fruiting myxobacterium Stigmatella aurantiaca.

When the fruiting myxobacterium Stigmatella aurantiaca, a gliding prokaryote, is starved on an agar surface, the cells form multicellular aggregates resulting from morphogenetic movements. In the presence of incandescent light, each aggregate develops into a structurally complex fruiting body, possessing a stalk and several sporangia. In contrast, this pattern of development is not seen when cultures are incubated in the dark. The cells form irregular interconnecting aggregates, which rarely develop into fruits. However, aggregates formed in the light will develop into fruits even if placed in the dark, suggesting that the light produced a relatively stable alteration in the phenotype of the cells.

Light↗
PubMed1969

Fine structure of fruiting bodies of Stigmatella aurantiaca (Myxobacterales).

The fruiting body of Stigmatella aurantiaca consists of a thick stalk supporting a number of individual cysts. The stalk is made of discontinuous tubules, of dimensions known for vegetative cells, which are oriented parallel to the longitudinal axis of the stalk. The red-brown cysts contain numerous, randomly oriented myxospores which are surrounded by thick, fibrous capsules. Their cell walls are wavy or ruffled and exhibit fewer budlike infoldings than reported for myxospores induced in liquid. We suggest that the extended time period available for metabolic and regulatory adjustments by the cell during morphogenesis within cysts accounts for the presence of considerably fewer deep cell wall infoldings than in glycerol-induced myxospores.

Bacteria↗
PubMed1980

Development of Stigmatella aurantiaca: effects of light and gene expression.

Stigmatella aurantiaca, a gliding, gram-negative bacterium, exhibits complex developmental changes upon starvation. In the light the cells aggregate and develop multicellular fruiting bodies with stalks and sporangia within 20 h. Between 23 and 27 h, sonication-resistant myxospores are synchronously formed inside the sporangia. On the other hand, in the dark, the cells aggregate and differentiate into myxospores between 13 and 27 h without forming stalks and sporangia. The pattern of protein synthesis during development in the light as well as in the dark was investigated. Three periods of synthesis, characterized by sharp increases and decreases in the rate of isotope incorporation into certain proteins, were distinguished. In the light these periods corresponded approximately to an early stage before the formation of aggregates, a middle period during which aggregates appeared and developed into fruiting bodies, and a late stage that corresponded to the appearance of myxospores. The pattern of protein synthesis in the dark could also be divided into three stages, but the middle stage was considerably shorter than in the light and showed diminished synthesis of certain proteins that were actively synthesized in the light. In particular, the synthesis of one protein was detected only in samples that developed in the light.

Bacterial Proteins↗
PubMed1980

Photocontrol of development by Stigmatella aurantiaca.

Aggregation and fruiting body formation by Stigmatella aurantiaca were stimulated most effectively by low irradiances of blue light between 400 and 500 nm. At higher irradiances, other wavelengths of light, including those in the far-red region of the spectrum, were also effective.

Light↗
PubMed1992

Cell surface modifications induced by calcium ion in the myxobacterium Stigmatella aurantiaca.

Calcium ion induces in the myxobacterium Stigmatella aurantiaca the ability to glide on solid surfaces and to become cohesive (D. F. Gilmore and D. White, J. Bacteriol. 161:113-117, 1985; B. J. Womack, D. F. Gilmore, and D. White, J. Bacteriol. 171:6093-6096, 1989). The addition of calcium ion to the growth medium resulted in the formation of extracellular fibrils, the appearance in the membrane fractions of a 30-kDa protein, and the accumulation in a low-speed centrifugal pellet of 10 polypeptides that cross-reacted with affinity-purified antibody to one of the polypeptides. One of the polypeptides, a 55-kDa protein, was present in the membrane fraction of control cells not incubated with calcium ion and was apparently translocated to the extracellular matrix during incubation in medium containing calcium ion. The 55-kDa protein was immunologically related to a 65-kDa protein located on the fibrils of another myxobacterium, Myxococcus xanthus.

Bacterial Proteins↗
PubMed1969

Structural changes in Stigmatella aurantiaca during myxospore induction.

Suspension cultures of Stigmatella aurantiaca (Chondromyces aurantiacus) were induced to form myxospores by addition of glycerol to the growing culture. The cells were fixed at various stages during conversion, thin sections were prepared, and changes in fine structure were studied. Vegetative cells are quite similar in their ultrastructure to Myxococcus xanthus. During transformation into myxospores, three important cytological changes were observed. Granules of storage material, probably polysaccharide and polyphosphate, accumulated; a 200 to 300-mum thick capsule was laid down, and the outer triple layer of the cell wall became locally folded. These cell wall folds were often densely packed and lay in pockets formed by the cytoplasmic membrane. We have suggested the possibility that the cell may store in these folds wall material which has become superfluous by the decrease in surface area during conversion.

Bacteria↗
PubMed1998

Independent patterns of expression of two alternative sigma factors, sigB and sigC, of the myxobacterium Stigmatella aurantiaca during development.

The transcription of many spatially and temporally controlled developmental genes is required for cellular differentiation of the myxobacterium Stigmatella aurantiaca. The expression patterns of the sigma factor gene sigB and of a novel alternative sigma factor gene sigC have been studied during development of Stigmatella aurantiaca. They are expressed at different stages of development. sigB is expressed from the very beginning of fruiting body formation to the sporulation step, while sigC expression takes place later, from the stalk formation to the sporulation step. Neither sigB nor sigC are expressed during heat shock. A sigB mutant and a sigC mutant have been constructed by gene replacement. Their analysis has shown that sigB and sigC expression are independent from each other.

Bacterial Proteins↗
PubMed1980

Morphogenetic effects of light and guanine derivatives on the fruiting myxobacterium Stigmatella aurantiaca.

When low cell densities of the myxobacterium Stigmatella aurantiaca were starved on an inorganic salts and agar medium, cell aggregation and fruiting body formation showed a striking dependency upon the presence of light. This dependency was not manifested when sufficient amounts of guanosine or guanine nucleotides were added to the medium. Light interacted cooperatively with suboptimal concentrations of guanine compounds to promote development. None of the other purine or pyrimidine derivatives, with the exception of adenine, stimulated development. However, aggregates that formed in the presence of adenine did not mature into fruiting bodies and instead disaggregated.

Guanine Nucleotides↗
PubMed1993

Heat shock and development induce synthesis of a low-molecular-weight stress-responsive protein in the myxobacterium Stigmatella aurantiaca.

In the fruiting body-forming myxobacterium Stigmatella aurantiaca a 21,000-M(r) protein, SP21, is synthesized during fruiting, heat shock, and stress induced by oxygen limitation. The corresponding gene was isolated from a gene expression library in lambda gt11 with an antiserum to the purified protein. The DNA sequence of the gene reveals that SP21 is a member of the alpha-crystallin family of low-molecular-weight heat shock proteins.

Amino Acid Sequence↗
PubMed1993

A physical and genetic map of the Stigmatella aurantiaca DW4/3.1 chromosome.

A physical map of the myxobacterium Stigmatella aurantiaca DW4/3.1 chromosome was constructed by pulsed-field gel (PFG) long-range mapping. One-and two-dimensional pulsed-field gel analyses were used together with reciprocal double-restriction, cross-hybridization and hybridization fingerprint analysis. These PFG results were confirmed by Smith-Birnstiel analysis, by Southern hybridization using linking clones and clones of a lambda genomic library for the determination of adjacent restriction fragments and by transposon insertion mapping using defined genomic sequences for hybridization. It was thus possible to construct a circular restriction map of the single 9.35 Mbp chromosome of S. aurantiaca based on the endonucleases Asel and Spel. Genetic loci as well as the replication origin were located on the physical map by Southern hybridization using heterologous (derived from Myxococcus xanthus, Escherichia coli and Streptomyces lividans) and homologous probes that are mainly involved in development and cell motility.

Bacteriophage lambda↗