scholarly journals Genetic Transformation in Cryptococcus Species

2021 ◽  
Vol 7 (1) ◽  
pp. 56
Author(s):  
Ping Wang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Transformation ◽  
Gene Disruption ◽  
Pathogenic Fungus ◽  
Cryphonectria Parasitica ◽  
Resistance Mechanisms ◽  
Dna Transformation ◽  
Methods And Techniques ◽  
Cryptococcus Species ◽  
The Subject

Genetic transformation plays an imperative role in our understanding of the biology in unicellular yeasts and filamentous fungi, such as Saccharomyces cerevisiae, Aspergillus nidulans, Cryphonectria parasitica, and Magnaporthe oryzae. It also helps to understand the virulence and drug resistance mechanisms of the pathogenic fungus Cryptococcus that causes cryptococcosis in health and immunocompromised individuals. Since the first attempt at DNA transformation in this fungus by Edman in 1992, various methods and techniques have been developed to introduce DNA into this organism and improve the efficiency of homology-mediated gene disruption. There have been many excellent summaries or reviews covering the subject. Here we highlight some of the significant achievements and additional refinements in the genetic transformation of Cryptococcus species.

scholarly journals The Schizosaccharomyces pombe cho1+ Gene Encodes a Phospholipid Methyltransferase

Genetics ◽  
1998 ◽  
Vol 150 (2) ◽  
pp. 553-562
Author(s):  
Margaret I Kanipes ◽  
John E Hill ◽  
Susan A Henry
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sequence Analysis ◽  
Schizosaccharomyces Pombe ◽  
Gene Disruption ◽  
Structure And Function ◽  
Biosynthetic Enzyme ◽  
Gene Encoding ◽  
Complementation Groups ◽  
Eukaryotic Organisms ◽  
And Function

Abstract The isolation of mutants of Schizosaccharomyces pombe defective in the synthesis of phosphatidylcholine via the methylation of phosphatidylethanolamine is reported. These mutants are choline auxotrophs and fall into two unlinked complementation groups, cho1 and cho2. We also report the analysis of the cho1+ gene, the first structural gene encoding a phospholipid biosynthetic enzyme from S. pombe to be cloned and characterized. The cho1+ gene disruption mutant (cho1Δ) is viable if choline is supplied and resembles the cho1 mutants isolated after mutagenesis. Sequence analysis of the cho1+ gene indicates that it encodes a protein closely related to phospholipid methyltransferases from Saccharomyces cerevisiae and rat. Phospholipid methyltransferases encoded by a rat liver cDNA and the S. cerevisiae OPI3 gene are both able to complement the choline auxotrophy of the S. pombe cho1 mutants. These results suggest that both the structure and function of the phospholipid N-methyltransferases are broadly conserved among eukaryotic organisms.

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 Using Chimeric Hypoviruses To Fine-Tune the Interaction between a Pathogenic Fungus and Its Plant Host

2000 ◽  
Vol 74 (16) ◽  
pp. 7562-7567 ◽  
Author(s):  
Baoshan Chen ◽  
Lynn M. Geletka ◽  
Donald L. Nuss
Keyword(s):  
Pathogenic Fungus ◽  
Cryphonectria Parasitica ◽  
Cdna Clones ◽  
Plant Host ◽  
Reading Frame ◽  
Ecological Fitness ◽  
Severe Strain ◽  
Fungal Isolates ◽  
Virulence Attenuation ◽  
Fine Tune

ABSTRACT Infectious cDNA clones of mild (CHV1-Euro7) and severe (CHV1-EP713) hypovirus strains responsible for virulence attenuation (hypovirulence) of the chestnut blight fungus Cryphonectria parasitica were used to construct viable chimeric viruses. Differences in virus-mediated alterations of fungal colony morphology, growth rate, and canker morphology were mapped to a region of open reading frame B extending from nucleotides 2,363 to 9,904. By swapping domains within this region, it was possible to generate chimeric hypovirus-infectedC. parasitica isolates that exhibited a spectrum of defined colony and canker morphologies. Several severe strain traits were observed to be dominant. It was also possible to uncouple the severe strain traits of small canker size and suppression of asexual sporulation. For example, fungal isolates infected with a chimera containing nucleotides 2363 through 5310 from CHV1-Euro7 in a CHV1-713 background formed small cankers that were similar in size to that caused by CHV1-EP713-infected isolates but with the capacity for producing asexual spores at levels approaching that observed for fungal isolates infected with the mild strain. These results demonstrate that hypoviruses can be engineered to fine-tune the interaction between a pathogenic fungus and its plant host. The identification of specific hypovirus domains that differentially contribute to canker morphology and sporulation levels also provides considerable utility for continuing efforts to enhance biological control potential by balancing hypovirulence and ecological fitness.

scholarly journals Analysis of the results of the implementation of a structural and functional didactic model for the development of cartographic literacy in the training of students of pedagogical specialties

2018 ◽  
Vol 15 ◽  
pp. 116-135 ◽  
Author(s):  
Marian Georgiev Delchev
Keyword(s):  
Qualitative Analysis ◽  
Experimental Work ◽  
Professional Competence ◽  
Nonparametric Methods ◽  
Diagnostic Tools ◽  
Methods And Techniques ◽  
The Subject

The complexity of the components of the complex cartographic literacy and subject-oriented methodological professional competence, as well as the process of their formation, requires the use of specific diagnostic tools and parametric and nonparametric methods and techniques for quantitative and qualitative analysis. The subject of this paper is the model of the processing of data from the study, the main results found during the experimental work and their statistical and qualitative analysis.

scholarly journals Dal81 Regulates Expression of Arginine Metabolism Genes inCandida parapsilosis

mSphere ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Siobhan A. Turner ◽  
Qinxi Ma ◽  
Mihaela Ola ◽  
Kontxi Martinez de San Vicente ◽  
Geraldine Butler
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Pathogenic Fungus ◽  
Nitrogen Sources ◽  
Nitrogen Utilization ◽  
Nitrogen Regulation ◽  
Transcriptional Level ◽  
Pathogenic Yeast ◽  
Secondary Sources ◽  
Expression Of Genes ◽  
Maximal Induction

ABSTRACTFungi can use a wide variety of nitrogen sources. In the absence of preferred sources such as ammonium, glutamate, and glutamine, secondary sources, including most other amino acids, are used. Expression of the nitrogen utilization pathways is very strongly controlled at the transcriptional level. Here, we investigated the regulation of nitrogen utilization in the pathogenic yeastCandida parapsilosis. We found that the functions of many regulators are conserved with respect toSaccharomyces cerevisiaeand other fungi. For example, the core GATA activatorsGAT1andGLN3have a conserved role innitrogencataboliterepression (NCR). There is one ortholog ofGZF3andDAL80, which represses expression of genes in preferred nitrogen sources. The regulatorsPUT3andUGA3are required for metabolism of proline and γ-aminobutyric acid (GABA), respectively. However, the role of the Dal81 transcription factor is distinctly different. InS. cerevisiae, Dal81 is a positive regulator of acquisition of nitrogen from GABA, allantoin, urea, and leucine, and it is required for maximal induction of expression of the relevant pathway genes. InC. parapsilosis, induction of GABA genes is independent of Dal81, and deletingDAL81has no effect on acquisition of nitrogen from GABA or allantoin. Instead, Dal81 represses arginine synthesis during growth under preferred nitrogen conditions.IMPORTANCEUtilization of nitrogen by fungi is controlled bynitrogencataboliterepression (NCR). Expression of many genes is switched off during growth on nonpreferred nitrogen sources. Gene expression is regulated through a combination of activation and repression. Nitrogen regulation has been studied best in the model yeastSaccharomyces cerevisiae. We found that although many nitrogen regulators have a conserved function inSaccharomycesspecies, some do not. The Dal81 transcriptional regulator has distinctly different functions inS. cerevisiaeandC. parapsilosis. In the former, it regulates utilization of nitrogen from GABA and allantoin, whereas in the latter, it regulates expression of arginine synthesis genes. Our findings make an important contribution to our understanding of nitrogen regulation in a human-pathogenic fungus.

The Importance Of The Subject "Art Photo Composition" In The Study Of Photo Art

2021 ◽  
Vol 03 (03) ◽  
pp. 84-88
Author(s):  
Jasur Jumaev ◽  
Keyword(s):  
General Purpose ◽  
Methods And Techniques ◽  
The Subject ◽  
Basic Concepts ◽  
Photo Composition

The article covers the basic concepts of artistic photo composition, the general purpose of the composition, the artist's use of visual and expressive means of this art, the use of specific methods and techniques of constructive construction.

SAM2 encodes the second methionine S-adenosyl transferase in Saccharomyces cerevisiae: physiology and regulation of both enzymes

1988 ◽  
Vol 8 (12) ◽  
pp. 5132-5139
Author(s):  
D Thomas ◽  
R Rothstein ◽  
N Rosenberg ◽  
Y Surdin-Kerjan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Disruption ◽  
Double Mutant ◽  
State Level ◽  
Functional Complementation ◽  
The Other ◽  
Steady State Level ◽  
Duplicated Genes ◽  
Double Mutant Strain ◽  
Adomet Synthetase

In Saccharomyces cerevisiae the SAM1 and SAM2 genes encode two distinct forms of S-adenosylmethionine (AdoMet) synthetase. In a previous study we cloned and sequenced the SAM1 gene (D. Thomas and Y. Surdin-Kerjan, J. Biol. Chem. 262:16704-16709, 1987). In this work, the SAM2 gene was isolated by functional complementation of a yeast double-mutant strain, and its identity was ascertained by gene disruption. It has been sequenced and compared with the SAM1 gene. The degree of homology found between the two genes shows that SAM1 and SAM2 are duplicated genes. Using strains disrupted in one or the other SAM gene, we have studied the regulation of their expression by measuring the steady-state level of mRNA after growth under different conditions. The results show that the expression of the two SAM genes is regulated differently, SAM2 being induced by the presence of excess methionine in the growth medium and SAM1 being repressed under the same conditions. The level of mRNA in the parental strain shows that it is not the sum of the levels found in the two disrupted strains. This raises the question of how the two AdoMet synthetases in S. cerevisiae interact to control AdoMet synthesis.

scholarly journals Resistance Mechanisms of Saccharomyces cerevisiae to Commercial Formulations of Glyphosate Involve DNA Damage Repair, the Cell Cycle, and the Cell Wall Structure

2020 ◽  
Vol 10 (6) ◽  
pp. 2043-2056
Author(s):  
Apoorva Ravishankar ◽  
Amaury Pupo ◽  
Jennifer E. G. Gallagher
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Resistance Mechanisms ◽  
Mapk Signaling ◽  
Fragile Sites ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Global Changes ◽  
Expression Of Genes ◽  
Wide Range

The use of glyphosate-based herbicides is widespread and despite their extensive use, their effects are yet to be deciphered completely. The additives in commercial formulations of glyphosate, though labeled inert when used individually, have adverse effects when used in combination with other additives along with the active ingredient. As a species, Saccharomyces cerevisiae has a wide range of resistance to glyphosate-based herbicides. To investigate the underlying genetic differences between sensitive and resistant strains, global changes in gene expression were measured, when yeast were exposed to a glyphosate-based herbicide (GBH). Expression of genes involved in numerous pathways crucial to the cell’s functioning, such as DNA replication, MAPK signaling, meiosis, and cell wall synthesis changed. Because so many diverse pathways were affected, these strains were then subjected to in-lab-evolutions (ILE) to select mutations that confer increased resistance. Common fragile sites were found to play a role in adaptation to resistance to long-term exposure of GBHs. Copy number increased in approximately 100 genes associated with cell wall proteins, mitochondria, and sterol transport. Taking ILE and transcriptomic data into account it is evident that GBHs affect multiple biological processes in the cell. One such component is the cell wall structure which acts as a protective barrier in alleviating the stress caused by exposure to inert additives in GBHs. Sed1, a GPI-cell wall protein, plays an important role in tolerance of a GBH. Hence, a detailed study of the changes occurring at the genome and transcriptome levels is essential to better understand the effects of an environmental stressor such as a GBH, on the cell as a whole.

Explanation in Prehistory

1971 ◽  
Vol 37 (1) ◽  
pp. 38-55 ◽  
Author(s):  
J. C. Harriss
Keyword(s):  
Numerical Methods ◽  
Academic Discipline ◽  
Well Being ◽  
Natural Sciences ◽  
Prehistoric Archaeology ◽  
Methods And Techniques ◽  
The Subject

Jacquetta Hawkes in a paper called ‘The Proper Study of Mankind’ (Hawkes, 1968) has made an impassioned plea against what she considers to be the ‘dehumanization’ of prehistory at the hands of those who have sought to apply to it numerical methods and the techniques of the natural sciences. There can be few who do not sympathize with her denunciation of aimless manipulation of data and the use of techniques for their own sakes; and many must share Clark's fear that prehistoric archaeology will serve merely ‘… to provide intellectual games for the meritocracy’ (Clark, 1967, 472). But such comments as these only prompt the question ‘what are we studying prehistory for?’ or ‘what is prehistory about?’The well-being of any academic discipline depends upon the posing of questions like these, for if a subject is to develop at all, it must undergo periods of self-analysis when some of its practitioners take stock of what they themselves and others are doing. The analysis may be concerned with methods and techniques and may either tacitly or openly accept the existing philosophy. Or it may consider the philosophy of the subject directly, by asking if the priorities of a past age are still acceptable or whether in the different climate of thought of the present, they must be changed. Self-analysis of this kind may however produce a state of unease and disquiet.

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