scholarly journals EspC Is Involved in Controlling the Timing of Development in Myxococcus xanthus

2005 ◽  
Vol 187 (14) ◽  
pp. 5029-5031 ◽  
Author(s):  
Bongsoo Lee ◽  
Penelope I. Higgs ◽  
David R. Zusman ◽  
Kyungyun Cho

ABSTRACT The espC null mutation caused accelerated aggregation and formation of tiny fruiting bodies surrounded by spores, which were also observed in the espA mutant and in CsgA-overproducing cells in Myxococcus xanthus. In addition, the espC mutant appeared to produce larger amounts of the complementary C-signal than the wild-type strain. These findings suggest that EspC is involved in controlling the timing of fruiting body development in M. xanthus.

2004 ◽  
Vol 186 (13) ◽  
pp. 4361-4368 ◽  
Author(s):  
Jimmy S. Jakobsen ◽  
Lars Jelsbak ◽  
Lotte Jelsbak ◽  
Roy D. Welch ◽  
Craig Cummings ◽  
...  

ABSTRACT A search of the M1genome sequence, which includes 97% of the Myxococcus xanthus genes, identified 53 sequence homologs of σ54-dependent enhancer binding proteins (EBPs). A DNA microarray was constructed from the M1genome that includes those homologs and 318 other M. xanthus genes for comparison. To screen the developmental program with this array, an RNA extract from growing cells was compared with one prepared from developing cells at 12 h. Previous reporter studies had shown that M. xanthus has initiated development and has begun to express many developmentally regulated genes by 12 h. The comparison revealed substantial increases in the expression levels of 11 transcription factors that may respond to environmental stimuli. Six of the 53 EBP homologs were expressed at significantly higher levels at 12 h of development than during growth. Three were previously unknown genes, and they were inactivated to look for effects on fruiting body development. One knockout mutant produced fruiting bodies of abnormal shape that depended on the composition of the medium.


1998 ◽  
Vol 180 (23) ◽  
pp. 6215-6223 ◽  
Author(s):  
Di Xu ◽  
Chun Yang ◽  
Heidi B. Kaplan

ABSTRACT Myxococcus xanthus multicellular fruiting body development is initiated by nutrient limitation at high cell density. Five clustered point mutations (sasB5, -14, -15, -16, and -17) can bypass the starvation and high-cell-density requirements for expression of the4521 developmental reporter gene. These mutants express4521 at high levels during growth and development in anasgB background, which is defective in generation of the cell density signal, A signal. A 1.3-kb region of the sasBlocus cloned from the wild-type chromosome restored the SasB+ phenotype to the five mutants. DNA sequence analysis of the 1.3-kb region predicted an open reading frame, designated SasN. The N terminus of SasN appears to contain a strongly hydrophobic region and a leucine zipper motif. SasN showed no significant sequence similarities to known proteins. A strain containing a newly constructedsasN-null mutation and Ω4521 Tn5lac in an otherwise wild-type background expressed 4521 at a high level during growth and development. A similar sasN-null mutant formed abnormal fruiting bodies and sporulated at about 10% the level of wild type. These data indicate that the wild-typesasN gene product is necessary for normal M. xanthus fruiting body development and functions as a critical regulator that prevents 4521 expression during growth.


2021 ◽  
Author(s):  
Laszlo G Nagy ◽  
Peter Jan Vonk ◽  
Markus Kunzler ◽  
Csenge Foldi ◽  
Mate Viragh ◽  
...  

Fruiting bodies of mushroom-forming fungi (Agaricomycetes) are among the most complex structures produced by fungi. Unlike vegetative hyphae, fruiting bodies grow determinately and follow a genetically encoded developmental program that orchestrates tissue differentiation, growth and sexual sporulation. In spite of more than a century of research, our understanding of the molecular details of fruiting body morphogenesis is limited and a general synthesis on the genetics of this complex process is lacking. In this paper, we aim to comprehensively identify conserved genes related to fruiting body morphogenesis and distill novel functional hypotheses for functionally poorly characterized genes. As a result of this analysis, we report 921 conserved developmentally expressed gene families, only a few dozens of which have previously been reported in fruiting body development. Based on literature data, conserved expression patterns and functional annotations, we provide informed hypotheses on the potential role of these gene families in fruiting body development, yielding the most complete description of molecular processes in fruiting body morphogenesis to date. We discuss genes related to the initiation of fruiting, differentiation, growth, cell surface and cell wall, defense, transcriptional regulation as well as signal transduction. Based on these data we derive a general model of fruiting body development, which includes an early, proliferative phase that is mostly concerned with laying out the mushroom body plan (via cell division and differentiation), and a second phase of growth via cell expansion as well as meiotic events and sporulation. Altogether, our discussions cover 1480 genes of Coprinopsis cinerea, and their orthologs in Agaricus bisporus, Cyclocybe aegerita, Armillaria ostoyae, Auriculariopsis ampla, Laccaria bicolor, Lentinula edodes, Lentinus tigrinus, Mycena kentingensis, Phanerochaete chrysosporium, Pleurotus ostreatus, and Schizophyllum commune, providing functional hypotheses for ~10% of genes in the genomes of these species. Although experimental evidence for the role of these genes will need to be established in the future, our data provide a roadmap for guiding functional analyses of fruiting related genes in the Agaricomycetes. We anticipate that the gene compendium presented here, combined with developments in functional genomics approaches will contribute to uncovering the genetic bases of one of the most spectacular multicellular developmental processes in fungi. Key words: functional annotation; comparative genomics; cell wall remodeling; development; fruiting body morphogenesis; mushroom; transcriptome


1979 ◽  
Vol 35 (1) ◽  
pp. 321-338
Author(s):  
C. Rossier ◽  
G. Gerisch ◽  
D. Malchow

Adenosine 3′,5′-cyclic phosphorothioate (cAMP-S) is a cyclic AMP (cAMP) analogue which is only slowly hydrolysed by phosphodiesterases of Dictyostelium discoideum. The affinity of cAMP-S to cAMP receptors at the cell surface is only one order of magnitude lower than that of cAMP. cAMP-S can replace cAMP as a stimulant with respect to all receptor-mediated responses tested, including chemotaxis and the induction of cAMP pulses. cAMP-S does not affect growth of D. discoideum but it blocks cell aggregation at a uniform concentration of 5 × 10(−7) M in agar plate cultures of strain NC-4 as well as its axenically growing derivative, Ax-2. Another wild-type strain of D. discoideum, v-12, is able to aggregate on agar plates supplemented with 1 mM cAMP-S. The development of Polysphondylium pallidum and P. violaceum is also highly cAMP-S resistant. In Ax-2 both differentiation from the growth phase to the aggregation-competent stage and chemotaxis are cAMP-S sensitive, whereas in v-12 only chemotaxis is inhibited. v-12 can still form streams of cohering cells and fruiting bodies when chemotaxis is inhibited by cAMP-S. Whereas cAMP induces differentiation into stalk cells at concentrations of 10(−3) or 10(−4) M, cAMP-S has the same effect in strain v-12 at the much lower concentration of 10(−6) M.


2007 ◽  
Vol 189 (15) ◽  
pp. 5675-5682 ◽  
Author(s):  
James E. Berleman ◽  
John R. Kirby

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.


Genetics ◽  
2019 ◽  
Vol 213 (4) ◽  
pp. 1545-1563 ◽  
Author(s):  
Ramona Lütkenhaus ◽  
Stefanie Traeger ◽  
Jan Breuer ◽  
Laia Carreté ◽  
Alan Kuo ◽  
...  

Many filamentous ascomycetes develop three-dimensional fruiting bodies for production and dispersal of sexual spores. Fruiting bodies are among the most complex structures differentiated by ascomycetes; however, the molecular mechanisms underlying this process are insufficiently understood. Previous comparative transcriptomics analyses of fruiting body development in different ascomycetes suggested that there might be a core set of genes that are transcriptionally regulated in a similar manner across species. Conserved patterns of gene expression can be indicative of functional relevance, and therefore such a set of genes might constitute promising candidates for functional analyses. In this study, we have sequenced the genome of the Pezizomycete Ascodesmis nigricans, and performed comparative transcriptomics of developing fruiting bodies of this fungus, the Pezizomycete Pyronema confluens, and the Sordariomycete Sordaria macrospora. With only 27 Mb, the A. nigricans genome is the smallest Pezizomycete genome sequenced to date. Comparative transcriptomics indicated that gene expression patterns in developing fruiting bodies of the three species are more similar to each other than to nonsexual hyphae of the same species. An analysis of 83 genes that are upregulated only during fruiting body development in all three species revealed 23 genes encoding proteins with predicted roles in vesicle transport, the endomembrane system, or transport across membranes, and 13 genes encoding proteins with predicted roles in chromatin organization or the regulation of gene expression. Among four genes chosen for functional analysis by deletion in S. macrospora, three were shown to be involved in fruiting body formation, including two predicted chromatin modifier genes.


2007 ◽  
Vol 189 (21) ◽  
pp. 7937-7941 ◽  
Author(s):  
Cui-ying Zhang ◽  
Ke Cai ◽  
Hong Liu ◽  
Yong Zhang ◽  
Hong-wei Pan ◽  
...  

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.


1998 ◽  
Vol 180 (17) ◽  
pp. 4628-4637 ◽  
Author(s):  
Anthony G. Garza ◽  
Jeffrey S. Pollack ◽  
Baruch Z. Harris ◽  
Albert Lee ◽  
Ingrid M. Keseler ◽  
...  

ABSTRACT Myxococcus xanthus cells carrying the Ω4408 Tn5lac insertion at the sde locus show defects in fruiting body development and sporulation. Our analysis ofsde expression patterns showed that this locus is induced early in the developmental program (0 to 2 h) and that expression increases approximately fivefold after 12 h of development. Further studies showed that expression of sde is induced as growing cells enter stationary phase, suggesting that activation of thesde locus is not limited to the developmental process. Because the peak levels of sde expression in both ansde + and an sde mutant background were similar, we conclude that the sde locus is not autoregulated. Characterization of the sde locus by DNA sequence analysis indicated that the Ω4408 insertion occurred within the sdeK gene. Primer extension analyses localized the 5′ end of sde transcript to a guanine nucleotide 307 bp upstream of the proposed start for the SdeK coding sequence. The DNA sequence in the −12 and −24 regions upstream of the sdetranscriptional start site shows similarity to the ς54family of promoters. The results of complementation studies suggest that the defects in development and sporulation caused by the Ω4408 insertion are due to an inactivation of sdeK. The predicted amino acid sequence of SdeK was found to have similarity to the sequences of the histidine protein kinases of two-component regulatory systems. Based on our results, we propose that SdeK may be part of a signal transduction pathway required for the activation and propagation of the early developmental program.


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