scholarly journals Bypass of A- and B-Signaling Requirements for Myxococcus xanthus Development by Mutations in spdR

2002 ◽  
Vol 184 (5) ◽  
pp. 1455-1457 ◽  
Author(s):  
Hubert Tse ◽  
Ronald E. Gill
Keyword(s):  
Fruiting Body ◽  
Double Mutant ◽  
Myxococcus Xanthus ◽  
Wild Type ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Factor Production

ABSTRACT Mutations in spdR, previously reported to bypass the developmental requirement for B-signaling in Myxococcus xanthus, also bypass the requirement for A-signaling but not C-, D-, or E-signaling. Mutations in spdR restored nearly wild-type levels of sporulation to representative A-signal-deficient mutants carrying asgA476, asgB480, and asgC767 and improved the quality of fruiting body formation in the asgB480 mutant. The defect in A-factor production by the asgB480 mutant was not restored in the spdR2134 asgB480 double mutant.

scholarly journals Developmental Aggregation of Myxococcus xanthus Requires frgA, anfrz-Related Gene

2000 ◽  
Vol 182 (23) ◽  
pp. 6614-6621 ◽  
Author(s):  
Kyungyun Cho ◽  
Anke Treuner-Lange ◽  
Kathleen A. O'Connor ◽  
David R. Zusman
Keyword(s):  
Fruiting Body ◽  
Myxococcus Xanthus ◽  
Complex Life Cycle ◽  
Fruiting Bodies ◽  
Related Gene ◽  
Wild Type ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Extracellular Signals ◽  
Directed Motility

ABSTRACT Myxococcus xanthus is a gram-negative bacterium which has a complex life cycle that includes multicellular fruiting body formation. Frizzy mutants are characterized by the formation of tangled filaments instead of hemispherical fruiting bodies on fruiting agar. Mutations in the frz genes have been shown to cause defects in directed motility, which is essential for both vegetative swarming and fruiting body formation. In this paper, we report the discovery of a new gene, called frgA (forfrz-related gene), which confers a subset of the frizzy phenotype when mutated. The frgA null mutant showed reduced swarming and the formation of frizzy aggregates on fruiting agar. However, this mutant still displayed directed motility in a spatial chemotaxis assay, whereas the majority offrz mutants fail to show directed movements in this assay. Furthermore, the frizzy phenotype of the frgA mutant could be complemented extracellularly by wild-type cells or strains carrying non-frz mutations. The phenotype of the frgAmutant is similar to that of the abcA mutant and suggests that both of these mutants could be defective in the production or export of extracellular signals required for fruiting body formation rather than in the sensing of such extracellular signals. ThefrgA gene encodes a large protein of 883 amino acids which lacks homologues in the databases. The frgA gene is part of an operon which includes two additional genes, frgBand frgC. The frgB gene encodes a putative histidine protein kinase, and the frgC gene encodes a putative response regulator. The frgB and frgCnull mutants, however, formed wild-type fruiting bodies.

scholarly journals 3-Hydroxy-3-Methylglutaryl-Coenzyme A (CoA) Synthase Is Involved in Biosynthesis of Isovaleryl-CoA in the Myxobacterium Myxococcus xanthus during Fruiting Body Formation

2006 ◽  
Vol 188 (18) ◽  
pp. 6524-6528 ◽  
Author(s):  
Helge B. Bode ◽  
Michael W. Ring ◽  
Gertrud Schwär ◽  
Reiner M. Kroppenstedt ◽  
Dale Kaiser ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fruiting Body ◽  
Double Mutant ◽  
Coenzyme A ◽  
Alternative Pathway ◽  
Myxococcus Xanthus ◽  
Fruiting Body Formation ◽  
Dramatic Decrease ◽  
Body Formation ◽  
Reverse Transcription Pcr

ABSTRACT Isovaleryl-coenzyme A (IV-CoA) is the starting unit for some secondary metabolites and iso-odd fatty acids in several bacteria. According to textbook biochemistry, IV-CoA is derived from leucine degradation, but recently an alternative pathway that branches from the well-known mevalonate-dependent isoprenoid biosynthesis has been described for myxobacteria. A double mutant was constructed in Myxococcus xanthus by deletion of genes involved in leucine degradation and disruption of mvaS encoding the 3-hydroxy-3-methylglutaryl-coenzyme A synthase. A dramatic decrease of IV-CoA-derived iso-odd fatty acids was observed for the mutant, confirming mvaS to be involved in the alternative pathway. Additional quantitative real-time reverse transcription-PCR experiments indicated that mvaS is transcriptionally regulated by isovalerate. Furthermore, feeding studies employing an intermediate specific for the alternative pathway revealed that this pathway is induced during fruiting body formation, which presumably increases the amount of IV-CoA available when leucine is limited.

scholarly journals FibA and PilA act cooperatively during fruiting body formation of Myxococcus xanthus

2006 ◽  
Vol 61 (5) ◽  
pp. 1283-1293 ◽  
Author(s):  
Pamela J. Bonner ◽  
Wesley P. Black ◽  
Zhaomin Yang ◽  
Lawrence J. Shimkets
Keyword(s):  
Fruiting Body ◽  
Myxococcus Xanthus ◽  
Fruiting Body Formation ◽  
Body Formation

scholarly journals Multicellular Development in Myxococcus xanthus Is Stimulated by Predator-Prey Interactions

2007 ◽  
Vol 189 (15) ◽  
pp. 5675-5682 ◽  
Author(s):  
James E. Berleman ◽  
John R. Kirby
Keyword(s):  
Fruiting Body ◽  
Prey Availability ◽  
Process Analysis ◽  
Myxococcus Xanthus ◽  
Stringent Response ◽  
Fruiting Bodies ◽  
Fruiting Body Formation ◽  
Multicellular Development ◽  
Body Formation ◽  
Body Development

ABSTRACT Myxococcus xanthus is a predatory bacterium that exhibits complex social behavior. The most pronounced behavior is the aggregation of cells into raised fruiting body structures in which cells differentiate into stress-resistant spores. In the laboratory, monocultures of M. xanthus at a very high density will reproducibly induce hundreds of randomly localized fruiting bodies when exposed to low nutrient availability and a solid surface. In this report, we analyze how M. xanthus fruiting body development proceeds in a coculture with suitable prey. Our analysis indicates that when prey bacteria are provided as a nutrient source, fruiting body aggregation is more organized, such that fruiting bodies form specifically after a step-down or loss of prey availability, whereas a step-up in prey availability inhibits fruiting body formation. This localization of aggregates occurs independently of the basal nutrient levels tested, indicating that starvation is not required for this process. Analysis of early developmental signaling relA and asgD mutants indicates that they are capable of forming fruiting body aggregates in the presence of prey, demonstrating that the stringent response and A-signal production are surprisingly not required for the initiation of fruiting behavior. However, these strains are still defective in differentiating to spores. We conclude that fruiting body formation does not occur exclusively in response to starvation and propose an alternative model in which multicellular development is driven by the interactions between M. xanthus cells and their cognate prey.

scholarly journals Self-Driven Phase Transitions Drive Myxococcus xanthus Fruiting Body Formation

2019 ◽  
Vol 122 (24) ◽  
Author(s):  
Guannan Liu ◽  
Adam Patch ◽  
Fatmagül Bahar ◽  
David Yllanes ◽  
Roy D. Welch ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Fruiting Body ◽  
Myxococcus Xanthus ◽  
Fruiting Body Formation ◽  
Body Formation

scholarly journals Aggregation during Fruiting Body Formation in Myxococcus xanthus Is Driven by Reducing Cell Movement

2006 ◽  
Vol 189 (2) ◽  
pp. 611-619 ◽  
Author(s):  
Oleksii Sliusarenko ◽  
David R. Zusman ◽  
George Oster
Keyword(s):  
Fruiting Body ◽  
Myxococcus Xanthus ◽  
Cell Movement ◽  
Fruiting Bodies ◽  
Fruiting Body Formation ◽  
Agent Based ◽  
Body Formation ◽  
Early Stages ◽  
Cell Velocity ◽  
Reversal Frequency

ABSTRACT When starved, Myxococcus xanthus cells assemble themselves into aggregates of about 105 cells that grow into complex structures called fruiting bodies, where they later sporulate. Here we present new observations on the velocities of the cells, their orientations, and reversal rates during the early stages of fruiting body formation. Most strikingly, we find that during aggregation, cell velocities slow dramatically and cells orient themselves in parallel inside the aggregates, while later cell orientations are circumferential to the periphery. The slowing of cell velocity, rather than changes in reversal frequency, can account for the accumulation of cells into aggregates. These observations are mimicked by a continuous agent-based computational model that reproduces the early stages of fruiting body formation. We also show, both experimentally and computationally, how changes in reversal frequency controlled by the Frz system mutants affect the shape of these early fruiting bodies.

scholarly journals New Locus Important for Myxococcus Social Motility and Development

2007 ◽  
Vol 189 (21) ◽  
pp. 7937-7941 ◽  
Author(s):  
Cui-ying Zhang ◽  
Ke Cai ◽  
Hong Liu ◽  
Yong Zhang ◽  
Hong-wei Pan ◽  
...  
Keyword(s):  
Fruiting Body ◽  
Myxococcus Xanthus ◽  
Gliding Motility ◽  
Salt Tolerant ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Homologous Genes ◽  
Body Development ◽  
Fruiting Body Development ◽  
Social Motility

ABSTRACT The mts locus in salt-tolerant Myxococcus fulvus HW-1 was found to be critical for gliding motility, fruiting-body formation, and sporulation. The homologous genes in Myxococcus xanthus are also important for social motility and fruiting-body development. The mts genes were determined to be involved in cell-cell cohesion in both myxobacterial species.

scholarly journals fbfB, a Gene Encoding a Putative Galactose Oxidase, Is Involved in Stigmatella aurantiacaFruiting Body Formation

1998 ◽  
Vol 180 (5) ◽  
pp. 1241-1247 ◽  
Author(s):  
Barbara Silakowski ◽  
Heidi Ehret ◽  
Hans Ulrich Schairer
Keyword(s):  
Fruiting Body ◽  
Rhodobacter Capsulatus ◽  
Fusion Gene ◽  
Three Dimensional ◽  
Galactose Oxidase ◽  
Fruiting Bodies ◽  
Wild Type ◽  
Primary Alcohols ◽  
Fruiting Body Formation ◽  
Body Formation

ABSTRACT 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 fbfBgene is expressed about 14 h after induction of fruiting body formation as determined by measuring β-galactosidase activity in a merodiploid strain harboring the wild-type gene and anfbfB-Δtrp-lacZ fusion gene or by Northern (RNA) analysis with the Rhodobacter capsulatus pufBA fragment fused tofbfB 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.

In vitro stalk cell differentiation in wild-type and ‘slugger’ mutants of Dictyostelium discoideum

Development ◽  
1993 ◽  
Vol 118 (2) ◽  
pp. 523-526 ◽  
Author(s):  
K. Inouye ◽  
J. Gross
Keyword(s):  
Dictyostelium Discoideum ◽  
Fruiting Body ◽  
Cell Maturation ◽  
Stalk Cell ◽  
Wild Type ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Close Relationship ◽  
Long Time

In ‘slugger’ mutants of Dictyostelium discoideum, aggregates of cells remain for an abnormally long time in the migratory phase under conditions where wild-type aggregates form fruiting bodies. In the present work, we have examined the relationship between the defect in fruiting body formation in these mutants and their ability to form mature stalk cells. We dissociated anterior cells from slugs of the mutants and their parents and tested their ability to form stalk cells when incubated at low density in the presence of (1) the stalk cell morphogen Differentiation Inducing Factor-1 (DIF-1) together with cyclic AMP, or (2) 8-Br-cAMP, which is believed to penetrate cell membrane and activate cAMP- dependent protein kinase (PKA). Most of the mutants were markedly defective in forming stalk cells in response to DIF-1 plus cAMP, confirming a close relationship between fruiting body formation and stalk cell maturation. On the other hand, many of these same mutants formed stalk cells efficiently in response to 8-Br-cAMP. This supports evidence for an essential role of PKA in stalk cell maturation and fruiting body formation. It also indicates that many of the mutants owe their slugger phenotype to defects in functions required for optimal adenylyl cyclase activity.

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