The Effects of Salinity on the Mosquito Pathogenic Fungus Culicinomyces.

1978 ◽  
Vol 26 (1) ◽  
pp. 55 ◽  
Author(s):  
AW Sweeney
Keyword(s):  
Nutrient Medium ◽  
Culture Medium ◽  
Sea Water ◽  
Pathogenic Fungus ◽  
Hyphal Growth ◽  
Conidial Germination ◽  
Australian Isolate ◽  
Mosquito Larvae

An Australian isolate of the fungus Culicinomyces grows best on nutrient medium without additional salt. Conidial germination and hyphal growth are progressively reduced as the salinity of the culture medium is increased, with very restricted growth at 1.5 times the salinity of sea water. In the laboratory, the fungus will kill mosquito larvae reared at a salinity half that of sea water, but not those reared in sea water, and it appears that the ability of conidia to invade the infection sites of the gut is impaired under the latter conditions.

scholarly journals Transcription Profiling ofCandida albicansCells Undergoing the Yeast-to-Hyphal Transition

2002 ◽  
Vol 13 (10) ◽  
pp. 3452-3465 ◽  
Author(s):  
André Nantel ◽  
Daniel Dignard ◽  
Catherine Bachewich ◽  
Doreen Harcus ◽  
Anne Marcil ◽  
...  
Keyword(s):  
Time Course ◽  
Dna Microarrays ◽  
Culture Medium ◽  
Developmental Process ◽  
Pathogenic Fungus ◽  
Hyphal Growth ◽  
Transcription Profiles ◽  
Hyphal Morphology ◽  
External Signals ◽  
Temperature Time

The ability of the pathogenic fungus Candida albicans to switch from a yeast to a hyphal morphology in response to external signals is implicated in its pathogenicity. We used glass DNA microarrays to investigate the transcription profiles of 6333 predicted ORFs in cells undergoing this transition and their responses to changes in temperature and culture medium. We have identified several genes whose transcriptional profiles are similar to those of known virulence factors that are modulated by the switch to hyphal growth caused by addition of serum and a 37°C growth temperature. Time course analysis of this transition identified transcripts that are induced before germ tube initiation and shut off later in the developmental process. A strain deleted for the Efg1p and Cph1p transcription factors is defective in hyphae formation, and its response to serum and increased temperature is almost identical to the response of a wild-type strain grown at 37°C in the absence of serum. Thus Efg1p and Cph1p are needed for the activation of the transcriptional program that is induced by the presence of serum.

scholarly journals Release from Quorum-Sensing Molecules Triggers Hyphal Formation during Candida albicans Resumption of Growth

2005 ◽  
Vol 4 (7) ◽  
pp. 1203-1210 ◽  
Author(s):  
Brice Enjalbert ◽  
Malcolm Whiteway
Keyword(s):  
Candida Albicans ◽  
Quorum Sensing ◽  
Culture Medium ◽  
Pathogenic Fungus ◽  
Hyphal Growth ◽  
Growth Environment ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Hyphal Formation ◽  
Cyclin Genes

ABSTRACT Candida albicans is a pathogenic fungus able to change morphology in response to variations in its growth environment. Simple inoculation of stationary cells into fresh medium at 37°C, without any other manipulations, appears to be a powerful but transient inducer of hyphal formation; this process also plays a significant role in classical serum induction of hyphal formation. The mechanism appears to involve the release of hyphal repression caused by quorum-sensing molecules in the growth medium of stationary-phase cells, and farnesol has a strong but incomplete role in this process. We used DNA microarray technology to study both the resumption of growth of Candida albicans cells and molecular regulation involving farnesol. Maintaining farnesol in the culture medium during the resumption of growth both delays and reduces the induction of hypha-related genes yet triggers expression of genes encoding drug efflux components. The persistence of farnesol also prevents the repression of histone genes during hyphal growth and affects the expression of putative or demonstrated morphogenesis-regulating cyclin genes, such as HGC1, CLN3, and PCL2. The results suggest a model explaining the triggering of hyphae in the host based on quorum-sensing molecules.

scholarly journals The Aspergillus fumigatuscspA Gene Encoding a Repeat-Rich Cell Wall Protein Is Important for Normal Conidial Cell Wall Architecture and Interaction with Host Cells

2010 ◽  
Vol 9 (9) ◽  
pp. 1403-1415 ◽  
Author(s):  
Emma Levdansky ◽  
Oren Kashi ◽  
Haim Sharon ◽  
Yana Shadkchan ◽  
Nir Osherov
Keyword(s):  
Cell Wall ◽  
Pathogenic Fungus ◽  
Protein A ◽  
Surface Protein ◽  
Hyphal Growth ◽  
Cell Wall Protein ◽  
Conidial Germination ◽  
Host Cells ◽  
Cell Wall Degrading Enzymes ◽  
Content Type

ABSTRACT cspA (for cell surface protein A) encodes a repeat-rich glycophosphatidylinositol (GPI)-anchored cell wall protein (CWP) in the pathogenic fungus Aspergillus fumigatus. The number of repeats in cspA varies among isolates, and this trait is used for typing closely related strains of A. fumigatus. We have previously shown that deletion of cspA is associated with rapid conidial germination and reduced adhesion of dormant conidia. Here we show that cspA can be extracted with hydrofluoric acid (HF) from the cell wall, suggesting that it is a GPI-anchored CWP. The cspA-encoded CWP is unmasked during conidial germination and is surface expressed during hyphal growth. Deletion of cspA results in weakening of the conidial cell wall, whereas its overexpression increases conidial resistance to cell wall-degrading enzymes and inhibits conidial germination. Double mutant analysis indicates that cspA functionally interacts with the cell wall protein-encoding genes ECM33 and GEL2. Deletion of cspA together with ECM33 or GEL2 results in strongly reduced conidial adhesion, increased disorganization of the conidial cell wall, and exposure of the underlying layers of chitin and β-glucan. This is correlated with increasing susceptibility of the ΔcspA, ΔECM33, and ΔcspA ΔECM33 mutants to conidial phagocytosis and killing by human macrophages and hyphal damage induced by neutrophils. However, these strains did not exhibit altered virulence in mice with infected lungs. Collectively, these results suggest a role for cspA in maintaining the strength and integrity of the cell wall.

scholarly journals Characterization of the mbsA Gene Encoding a Putative APSES Transcription Factor in Aspergillus fumigatus

2021 ◽  
Vol 22 (7) ◽  
pp. 3777
Author(s):  
Yong-Ho Choi ◽  
Sang-Cheol Jun ◽  
Min-Woo Lee ◽  
Jae-Hyuk Yu ◽  
Kwang-Soo Shin
Keyword(s):  
Aspergillus Fumigatus ◽  
Pathogenic Fungus ◽  
Hyphal Growth ◽  
Spore Wall ◽  
Mrna Levels ◽  
Chitin Synthesis ◽  
Helix Loop Helix ◽  
Growth Development ◽  
Opportunistic Pathogenic

The APSES family proteins are transcription factors (TFs) with a basic helix-loop-helix domain, known to regulate growth, development, secondary metabolism, and other biological processes in Aspergillus species. In the genome of the human opportunistic pathogenic fungus Aspergillus fumigatus, five genes predicted to encode APSES TFs are present. Here, we report the characterization of one of these genes, called mbsA (Afu7g05620). The deletion (Δ) of mbsA resulted in significantly decreased hyphal growth and asexual sporulation (conidiation), and lowered mRNA levels of the key conidiation genes abaA, brlA, and wetA. Moreover, ΔmbsA resulted in reduced spore germination rates, elevated sensitivity toward Nikkomycin Z, and significantly lowered transcripts levels of genes associated with chitin synthesis. The mbsA deletion also resulted in significantly reduced levels of proteins and transcripts of genes associated with the SakA MAP kinase pathway. Importantly, the cell wall hydrophobicity and architecture of the ΔmbsA asexual spores (conidia) were altered, notably lacking the rodlet layer on the surface of the ΔmbsA conidium. Comparative transcriptomic analyses revealed that the ΔmbsA mutant showed higher mRNA levels of gliotoxin (GT) biosynthetic genes, which was corroborated by elevated levels of GT production in the mutant. While the ΔmbsA mutant produced higher amount of GT, ΔmbsA strains showed reduced virulence in the murine model, likely due to the defective spore integrity. In summary, the putative APSES TF MbsA plays a multiple role in governing growth, development, spore wall architecture, GT production, and virulence, which may be associated with the attenuated SakA signaling pathway.

scholarly journals Silencing of DND1 in potato and tomato impedes conidial germination, attachment and hyphal growth of Botrytis cinerea

2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Kaile Sun ◽  
Ageeth van Tuinen ◽  
Jan A. L. van Kan ◽  
Anne-Marie A. Wolters ◽  
Evert Jacobsen ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Hyphal Growth ◽  
Conidial Germination

scholarly journals Cell Wall-Related Bionumbers and Bioestimates of Saccharomyces cerevisiae and Candida albicans

2013 ◽  
Vol 13 (1) ◽  
pp. 2-9 ◽  
Author(s):  
Frans M. Klis ◽  
Chris G. de Koster ◽  
Stanley Brul
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Candida Albicans ◽  
Cell Size ◽  
Pathogenic Fungus ◽  
Turgor Pressure ◽  
Hyphal Growth ◽  
Biological Research ◽  
Content Type ◽  
Starting Point

ABSTRACTBionumbers and bioestimates are valuable tools in biological research. Here we focus on cell wall-related bionumbers and bioestimates of the budding yeastSaccharomyces cerevisiaeand the polymorphic, pathogenic fungusCandida albicans. We discuss the linear relationship between cell size and cell ploidy, the correlation between cell size and specific growth rate, the effect of turgor pressure on cell size, and the reason why using fixed cells for measuring cellular dimensions can result in serious underestimation ofin vivovalues. We further consider the evidence that individual buds and hyphae grow linearly and that exponential growth of the population results from regular formation of new daughter cells and regular hyphal branching. Our calculations show that hyphal growth allowsC. albicansto cover much larger distances per unit of time than the yeast mode of growth and that this is accompanied by strongly increased surface expansion rates. We therefore predict that the transcript levels of genes involved in wall formation increase during hyphal growth. Interestingly, wall proteins and polysaccharides seem barely, if at all, subject to turnover and replacement. A general lesson is how strongly most bionumbers and bioestimates depend on environmental conditions and genetic background, thus reemphasizing the importance of well-defined and carefully chosen culture conditions and experimental approaches. Finally, we propose that the numbers and estimates described here offer a solid starting point for similar studies of other cell compartments and other yeast species.

scholarly journals Melanin synthesis by black yeast-like fungi Psedonadsoniella brunnea: dependence of L-tyrosine quantity in the cultural medium

2019 ◽  
Vol 26 (1) ◽  
pp. 41-46 ◽  
Author(s):  
T. Kondratiuk ◽  
T. Beregova ◽  
T. Akulenko ◽  
Ie. Torgalo ◽  
V. Vereschaka
Keyword(s):  
Nutrient Medium ◽  
Culture Medium ◽  
Statistical Processing ◽  
Black Yeast ◽  
Malt Extract ◽  
Melanin Synthesis ◽  
Optimal Conditions ◽  
Cultural Medium ◽  
Yeast Fungi ◽  
Series Of Experiments

To determine the optimal conditions for the synthesis of melanin by black yeast fungi Pseudonadsoniella brunnea (Basidiomycota, Agaricomycotina, Agaricomycetes, Polyporales, Meripilaceae), depending on the amount of L-tyrosine in the culture medium was the purpose of the work. The standard Malt Extract Broth (MEB) liquid nutrient medium was used within this study. L-tyrosine was added to the culture medium in a quantity of 0.01, 0.025 and 0.05%.To obtain the melanin the cultivation of Pseudonadsoniella brunnea was carried out at pH 1-1.5, temperature + 21 ± 1 ° C during 7 days. Statistical processing of the results was carried out using generally accepted methods of variation statistics. It has been established that the level of melanin synthesis by black yeast-like fungi Pseudonadsoniella brunnea depends on the amount of L-tyrosine introduced into the culture medium. The MEB nutrient medium containing 0.05% L-tyrosine in this series of experiments found to be the best composition for obtaining melanin by the strain-producer Pseudonadsoniella brunnea. Compared to control (MEB without L-tyrosine), the amount of melanin synthesized by Ps. brunnea in these conditions increased by 2.5 times. The further research into the optimal conditions for the cultivation of black yeast-like fungi Pseudonadsoniella brunnea in order to obtain melanin is relevant and promising.

Dipeptidase PEPDA is required for the conidiation pattern shift in Metarhizium acridum

2021 ◽  
Author(s):  
Juan Li ◽  
Xueling Su ◽  
Yueqing Cao ◽  
Yuxian Xia
Keyword(s):  
Amino Acids ◽  
Filamentous Fungi ◽  
Pathogenic Fungus ◽  
Digital Gene Expression ◽  
Hyphal Growth ◽  
Metarhizium Acridum ◽  
Key Enzyme ◽  
Hydrolysis Of ◽  
Microcycle Conidiation

Filamentous fungi conduct two types of conidiation, typical conidiation from mycelia and microcycle conidiation (MC). Fungal conidiation can shift between the two patterns, which involved a large number of genes in the regulation of this process. In this study, we investigated the role of a dipeptidase gene pepdA in conidiation pattern shift in Metarhizium acridum , which is upregulated in MC pattern compared to typical conidiation. Results showed that disruption of the pepdA resulted in a shift of conidiation pattern from MC to typical conidiation. Metabolomic analyses of amino acids showed that the levels of 19 amino acids significantly changed in Δ pepdA mutant. The defect of MC in Δ pepdA can be rescued when nonpolar amino acids, α-alanine, β-alanine or proline, were added into s ucrose y east extract a gar (SYA) medium. Digital gene expression profiling analysis revealed that PEPDA mediated transcription of sets of genes which were involved in hyphal growth and development, sporulation, cell division, and amino acid metabolism. Our results demonstrated that PEPDA played important roles in the regulation of MC by manipulating the levels of amino acids in M. acridum . IMPORTANCE Conidia, as the asexual propagules in many fungi, are start and end of fungal lifecycle. In entomopathogenic fungi, conidia are the infective form essential for their pathogenicity. Filamentous fungi conduct two types of conidiation, typical conidiation from mycelia and microcycle conidiation. The mechanisms of the shift between the two conidiation patterns remain to be elucidated. In this study, we demonstrated that the dipeptidase PEPDA, a key enzyme from the insect-pathogenic fungus Metarhizium acridum for the hydrolysis of dipeptides, is associated with a shift of conidiation pattern. The conidiation pattern of the Δ pepdA mutant was restored when supplemented with the nonpolar amino acids rather than polar amino acids. Therefore, this report highlights that the dipeptidase PEPDA regulates MC by manipulating the levels of amino acids in M. acridum.

Mating-type genes control sexual reproduction, conidial germination and virulence in Cochliobolus lunatus

2021 ◽  
Author(s):  
Kexin Liu ◽  
Jiaqi Jia ◽  
Nan Chen ◽  
Dandan Fu ◽  
Jiaying Sun ◽  
...  
Keyword(s):  
Mating Type ◽  
Pathogenic Fungus ◽  
Germination Rate ◽  
Dry Weight ◽  
Single Copy ◽  
Conidial Germination ◽  
Curvularia Lunata ◽  
Wild Type ◽  
Cochliobolus Lunatus ◽  
Mat Genes

Cochliobolus lunatus (anamorph: Curvularia lunata) is a major pathogenic fungus that causes the Curvularia leaf spot of maize. ClMAT1-1-1 and ClMAT1-2-1, the C. lunatus orthologs of Cochliobolus heterostrophus ChMAT1-1-1 and ChMAT1-2-1, were investigated in the present study to uncover their functions in C. lunatus. Southern blot analysis showed that these mating-type MAT genes exist in the C. lunatus genome as a single copy. ClMAT1-1-1 and ClMAT1-2-1 were knocked out and complemented to generate ΔClmat1-1-1 and ΔClmat1-2-1, ΔClmat1-1-1-C and ΔClmat1-2-1-C, respectively. The mutant strains had defective sexual development and failed to produce pseudothecia. There were no significant differences in growth rate or conidia production between the mutant and wild-type strains. However, the aerial mycelia and mycelial dry weight of ΔClmat1-1-1 and ΔClmat1-2-1 were lower than that of wild type, suggesting that MAT genes affect asexual development. ClMAT genes were involved in the responses to cell wall integrity and osmotic adaptation. ΔClmat1-2-1 had a lower conidial germination rate than the wild-type strain CX-3. The virulence of ΔClmat1-2-1 and ΔClmat1-1-1 was also reduced compared to the wild type. Complementary strains could restore all the phenotypes.

scholarly journals II. Note on Dr. Fenton Evans’ paper on the pathogenic fungus of malaria

1891 ◽  
Vol 49 (296-301) ◽  
pp. 539-540
Keyword(s):  
Chemical Composition ◽  
Nutrient Medium ◽  
Pathogenic Fungus ◽  
Interesting Fact

The abstract of this paper published in this volume of the ‘Proceedings’ contains (p. 200) the following statement: "Alteration in the chemical composition of the nutrient medium . . . elicited the interesting fact that, under these circumstances, the organism can pass to a more highly developed state, displaying the structure and fructification of a highly organised fungus, but differing in certain important features from any fungus hitherto described."

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