scholarly journals A DnaK Homolog in Myxococcus xanthus Is Involved in Social Motility and Fruiting Body Formation

1998 ◽  
Vol 180 (2) ◽  
pp. 218-224 ◽  
Author(s):  
Zhaomin Yang ◽  
Yongzhi Geng ◽  
Wenyuan Shi
Keyword(s):  
Life Cycle ◽  
Myxococcus Xanthus ◽  
Complex Life Cycle ◽  
Phenotypic Characterization ◽  
Fruiting Body Formation ◽  
Gram Negative ◽  
Body Formation ◽  
The Social ◽  
Cellular Aggregation ◽  
Social Motility

ABSTRACT Myxococcus xanthus is a gram-negative soil bacterium which exhibits a complex life cycle and social behavior. In this study, two developmental mutants of M. xanthus were isolated through Tn5 transposon mutagenesis. The mutants were found to be defective in cellular aggregation as well as in sporulation. Further phenotypic characterization indicated that the mutants were defective in social motility but normal in directed cell movements. Both mutations were cloned by a transposon-tagging method. Sequence analysis indicated that both insertions occurred in the same gene, which encodes a homolog of DnaK. Unlike the dnaK genes in other bacteria, this M. xanthus homolog appears not to be regulated by temperature or heat shock and is constitutively expressed during vegetative growth and under starvation. The defects of the mutants indicate that this DnaK homolog is important for the social motility and development of M. xanthus.

scholarly journals SigF, a New Sigma Factor Required for a Motility System of Myxococcus xanthus

2005 ◽  
Vol 187 (24) ◽  
pp. 8537-8541 ◽  
Author(s):  
Toshiyuki Ueki ◽  
Chun-Ying Xu ◽  
Sumiko Inouye
Keyword(s):  
Gene Expression ◽  
Fruiting Body ◽  
Sigma Factor ◽  
Vegetative Growth ◽  
Growth Analysis ◽  
Myxococcus Xanthus ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
The Social ◽  
Social Motility

ABSTRACT A new sigma factor, SigF, was identified from the social and developmental bacterium Myxococcus xanthus. SigF is required for fruiting body formation during development as well as social motility during vegetative growth. Analysis of gene expression indicates that it is possible that the sigF gene is involved in regulation of an unidentified gene for social motility.

scholarly journals Methylation of FrzCD Defines a Discrete Step in the Developmental Program of Myxococcus xanthus

1998 ◽  
Vol 180 (21) ◽  
pp. 5765-5768 ◽  
Author(s):  
Yongzhi Geng ◽  
Zhaomin Yang ◽  
John Downard ◽  
David Zusman ◽  
Wenyuan Shi
Keyword(s):  
Fruiting Body ◽  
Myxococcus Xanthus ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Developmental Program ◽  
Discrete Step ◽  
Cellular Aggregation ◽  
Adaptation Response ◽  
Social Motility ◽  
Early Developmental

ABSTRACT Myxococcus xanthus is a gram-negative soil bacterium which undergoes fruiting body formation during starvation. Thefrz signal transduction system has been found to play an important role in this process. FrzCD, a methyl-accepting taxis protein homologue, shows modulated methylation during cellular aggregation, which is thought to be part of an adaptation response to an aggregation signal. In this study, we assayed FrzCD methylation in many known and newly isolated mutants defective in fruiting body formation to determine a possible relationship between the methylation response and fruiting morphology. The results of our analysis indicated that the developmental mutants could be divided into two groups based on their ability to show normal FrzCD methylation during development. Many mutants blocked early in development, i.e., nonaggregating or abnormally aggregating mutants, showed poor FrzCD methylation. The well-characterized asg, bsg, csg, and esg mutants were found to be of this type. The defects in FrzCD methylation of these signaling mutants could be partially rescued by extracellular complementation with wild-type cells or addition of chemicals which restore their fruiting body formation. Mutants blocked in late development, i.e., translucent mounds, showed normal FrzCD methylation. Surprisingly, some mutants blocked in early development also exhibited a normal level of FrzCD methylation. The characterized mutants in this group were found to be defective in social motility. This indicates that FrzCD methylation defines a discrete step in the development of M. xanthus and that social motility mutants are not blocked in these early developmental steps.

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 Neutral and Phospholipids of the Myxococcus xanthus Lipodome during Fruiting Body Formation and Germination

2015 ◽  
Vol 81 (19) ◽  
pp. 6538-6547 ◽  
Author(s):  
Tilman Ahrendt ◽  
Hendrik Wolff ◽  
Helge B. Bode
Keyword(s):  
Life Cycle ◽  
Lipid Profile ◽  
De Novo ◽  
Membrane Lipids ◽  
Myxococcus Xanthus ◽  
Model Organism ◽  
Ether Lipid ◽  
Complex Life Cycle ◽  
Fruiting Body Formation ◽  
Content Type

ABSTRACTMyxobacteria are well-known for their complex life cycle, including the formation of spore-filled fruiting bodies. The model organismMyxococcus xanthusexhibits a highly complex composition of neutral and phospholipids, including triacylglycerols (TAGs), diacylglycerols (DAGs), phosphatidylethanolamines (PEs), phosphatidylglycerols (PGs), cardiolipins (CLs), and sphingolipids, including ceramides (Cers) and ceramide phosphoinositols (Cer-PIs). In addition, ether lipids have been shown to be involved in development and signaling. In this work, we describe the lipid profile ofM. xanthusduring its entire life cycle, including spore germination. PEs, representing one of the major components of the bacterial membrane, decreased by about 85% during development from vegetative rods to round myxospores, while TAGs first accumulated up to 2-fold before they declined 48 h after the induction of sporulation. Presumably, membrane lipids are incorporated into TAG-containing lipid bodies, serving as an intermediary energy source for myxospore formation. The ceramides Cer(d-19:0/iso-17:0) and Cer(d-19:0/16:0) accumulated 6-fold and 3-fold, respectively, after 24 h of development, identifying them to be novel putative biomarkers forM. xanthussporulation. The most abundant ether lipid, 1-iso-15:0-alkyl-2,3-di-iso-15:0-acyl glycerol (TG1), exhibited a lipid profile different from that of all TAGs during sporulation, reinforcing its signaling character. The absence of all these lipid profile changes in mutants during development supports the importance of lipids in myxobacterial development. During germination of myxospores, only thede novobiosynthesis of new cell membrane fatty acids was observed. The unexpected accumulation of TAGs also during germination might indicate a function of TAGs as intermediary storage lipids during this part of the life cycle as well.

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.

Ultrastructural analysis of “Sensory” surface nerve endings and “putative” neurotransmitter sites in Schistosoma mansoni Miracidia

1989 ◽  
Vol 47 ◽  
pp. 962-963
Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tang Pan
Keyword(s):  
Nervous System ◽  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Snail Host ◽  
Complex Life Cycle ◽  
Rational Approach ◽  
Effective Control ◽  
The Social ◽  
Social And Economic Development ◽  
Basic Biology

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).

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 Gliding Motility Revisited: How Do the Myxobacteria Move without Flagella?

2010 ◽  
Vol 74 (2) ◽  
pp. 229-249 ◽  
Author(s):  
Emilia M. F. Mauriello ◽  
Tâm Mignot ◽  
Zhaomin Yang ◽  
David R. Zusman
Keyword(s):  
Biofilm Formation ◽  
Protein Localization ◽  
Myxococcus Xanthus ◽  
Gliding Motility ◽  
Solid Surfaces ◽  
Biological Functions ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Periplasmic Flagella ◽  
Motile Bacterium

SUMMARY In bacteria, motility is important for a wide variety of biological functions such as virulence, fruiting body formation, and biofilm formation. While most bacteria move by using specialized appendages, usually external or periplasmic flagella, some bacteria use other mechanisms for their movements that are less well characterized. These mechanisms do not always exhibit obvious motility structures. Myxococcus xanthus is a motile bacterium that does not produce flagella but glides slowly over solid surfaces. How M. xanthus moves has remained a puzzle that has challenged microbiologists for over 50 years. Fortunately, recent advances in the analysis of motility mutants, bioinformatics, and protein localization have revealed likely mechanisms for the two M. xanthus motility systems. These results are summarized in this review.

Sign in / Sign up

Export Citation Format

Share Document