CHARACTERIZATION OF THE HETEROKARYOTIC AND VEGETATIVE DIPLOID PHASES OF MAGNAPORTHE GRISEA

ABSTRACT The heterokaryotic and vegetative diploid phases of Magnaporthe grisea, a fungal pathogen of grasses, have been characterized. Prototrophic heterokaryons form when complementary auxotrophs are paired on minimal medium. Hyphal tip cells and conidia (vegetative spores) taken from these heterokaryons are auxotrophs with phenotypes identical to one or the other of the parents. M. grisea heterokaryons thus resemble those of other fungi that have completely septate hyphae with a single nucleus per cell. Heterokaryons have been utilized for complementation and dominance testing of mutations that affect nutritional characteristics of the fungus. Heterokaryons growing on minimal medium spontaneously give rise to fast-growing sectors that have the genetic properties expected of unstable heterozygous diploids. In fast-growing sectors, most hyphal tip cells are unstable prototrophs. The conidia collected from fast-growing sectors include stable and unstable prototrophs, as well as auxotrophs that exhibit a wide range of phenotypes, including many recombinant classes. Genetic linkage in meiosis has been detected between two auxotrophic mutations that recombine in vegetatively growing unstable diploids. The appearance of recombinants suggests that homologous recombination occurs during vegetative growth of M. grisea. No interstrain barriers to heterokaryosis and diploid formation have been detected. The mating type of the strains that are paired does not influence the formation of heterokaryons or diploids.

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Ash1 Protein, an Asymmetrically Localized Transcriptional Regulator, Controls Filamentous Growth and Virulence of Candida albicans

Molecular and Cellular Biology ◽

10.1128/mcb.22.24.8669-8680.2002 ◽

2002 ◽

Vol 22 (24) ◽

pp. 8669-8680 ◽

Cited By ~ 31

Author(s):

Diane O. Inglis ◽

Alexander D. Johnson

Keyword(s):

Candida Albicans ◽

Mouse Model ◽

Regulatory Protein ◽

Cell Nuclei ◽

Yeast Form ◽

Disseminated Candidiasis ◽

Transcriptional Regulatory ◽

Tip Cells ◽

Hyphal Tip

ABSTRACT In response to a number of distinct environmental conditions, the fungal pathogen Candida albicans undergoes a morphological transition from a round, yeast form to a series of elongated, filamentous forms. This transition is believed to be critical for virulence in a mouse model of disseminated candidiasis. Here we describe the characterization of C. albicans ASH1, a gene that encodes an asymmetrically localized transcriptional regulatory protein involved in this response. We show that C. albicans ash1 mutants are defective in responding to some filament-inducing conditions. We also show that Ash1p is preferentially localized to daughter cell nuclei in the budding-yeast form of C. albicans cell growth and to the hyphal tip cells in growing filaments. Thus, Ash1p “marks” newly formed cells and presumably directs a specialized transcriptional program in these cells. Finally, we show that ASH1 is required for full virulence of C. albicans in a mouse model of disseminated candidiasis.

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Morphological Characterization of Mycobacteriophage R1

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051281 ◽

1974 ◽

Vol 32 ◽

pp. 254-255

Author(s):

B. L. Soloff ◽

T. A. Rado

Keyword(s):

Carbon Source ◽

Stationary Phase ◽

Growth Phase ◽

Minimal Medium ◽

Morphological Characterization ◽

Logarithmic Growth Phase ◽

Complete Lysis ◽

Lysogenic Culture ◽

Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

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Polymer Chemistry

10.1093/oso/9780198503095.001.0001 ◽

2004 ◽

Keyword(s):

Conducting Polymers ◽

Liquid Crystalline ◽

Polymer Chemistry ◽

Chain Growth ◽

Crystalline Polymers ◽

Wide Range ◽

Cyclic Oligomers ◽

Step Growth

Polymer Chemistry: A Practical Approach in Chemistry has been designed for both chemists working in and new to the area of polymer synthesis. It contains detailed instructions for preparation of a wide-range of polymers by a wide variety of different techniques, and describes how this synthetic methodology can be applied to the development of new materials. It includes details of well-established techniques, e.g. chain-growth or step-growth processes together with more up-to-date examples using methods such as atom-transfer radical polymerization. Less well-known procedures are also included, e.g. electrochemical synthesis of conducting polymers and the preparation of liquid crystalline elastomers with highly ordered structures. Other topics covered include general polymerization methodology, controlled/"living" polymerization methods, the formation of cyclic oligomers during step-growth polymerization, the synthesis of conducting polymers based on heterocyclic compounds, dendrimers, the preparation of imprinted polymers and liquid crystalline polymers. The main bulk of the text is preceded by an introductory chapter detailing some of the techniques available to the scientist for the characterization of polymers, both in terms of their chemical composition and in terms of their properties as materials. The book is intended not only for the specialist in polymer chemistry, but also for the organic chemist with little experience who requires a practical introduction to the field.

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Organelle Genetics in Plants

International Journal of Molecular Sciences ◽

10.3390/ijms22042104 ◽

2021 ◽

Vol 22 (4) ◽

pp. 2104

Author(s):

Pedro Robles ◽

Víctor Quesada

Keyword(s):

Rna Editing ◽

Posttranscriptional Regulation ◽

Genome Engineering ◽

Plant Mitochondria ◽

Plastid Dna ◽

Chloroplast Genomes ◽

Wide Range ◽

Organelle Genetics ◽

Selection Of

Eleven published articles (4 reviews, 7 research papers) are collected in the Special Issue entitled “Organelle Genetics in Plants.” This selection of papers covers a wide range of topics related to chloroplasts and plant mitochondria research: (i) organellar gene expression (OGE) and, more specifically, chloroplast RNA editing in soybean, mitochondria RNA editing, and intron splicing in soybean during nodulation, as well as the study of the roles of transcriptional and posttranscriptional regulation of OGE in plant adaptation to environmental stress; (ii) analysis of the nuclear integrants of mitochondrial DNA (NUMTs) or plastid DNA (NUPTs); (iii) sequencing and characterization of mitochondrial and chloroplast genomes; (iv) recent advances in plastid genome engineering. Here we summarize the main findings of these works, which represent the latest research on the genetics, genomics, and biotechnology of chloroplasts and mitochondria.

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Morphometric and Nutritional Characterization of the Main Spanish Lentil Cultivars

Agriculture ◽

10.3390/agriculture11080741 ◽

2021 ◽

Vol 11 (8) ◽

pp. 741

Author(s):

Javier Plaza ◽

M. Remedios Morales-Corts ◽

Rodrigo Pérez-Sánchez ◽

Isabel Revilla ◽

Ana M. Vivar-Quintana

Keyword(s):

Scientific Evidence ◽

Nutrient Content ◽

Mediterranean Area ◽

Western Mediterranean ◽

Protein Food ◽

Content Assessment ◽

Protein Levels ◽

Nutritional Characteristics ◽

Clear Differentiation

Nowadays, there is a growing demand for high-quality vegetal protein food products, such as pulses and lentils in particular. However, there is no scientific evidence on the nutritional and morphometric characterization of the main lentil cultivars in the Western Mediterranean area. For this reason, the aim of this work is to carry out a morphometric and nutritional characterization of the main Spanish lentil cultivars. Nutrient content assessment was performed on dry matter. The results showed that all studied cultivars are large and heavy lentils, except for the cultivar “Pardina”. They have high protein levels, ranging from 21% to 25%, which is higher than those found in any other pulse, as well as a high carbohydrate content, greater than 59% in all cases. Fiber content was higher than expected in “Armuña” and “Rubia Castellana” cultivars, ranging from 6% to 6.6%, and exceptionally high in the case of the cultivar “Pardina”, which reached 7.8%. Conversely, very low values were found for fat content, varying between 0.5% and 0.9%. Ca, Fe and Mg levels were remarkably higher (from 550 ppm to 851 ppm, from 98 ppm to 139 ppm and from 790 ppm to 989 ppm, respectively) than those found for other lentil cultivars, especially the high Mg content in the cultivars “Jaspeada” and “Microjaspeada”, both above 955 ppm. Clear differentiation was found between the cultivars “Rubia Castellana”, “Pardina” and those included in the Protected Geographical Indication (PGI) “Lenteja de la Armuña”. Overall, lentil cultivars included in the PGI “Lenteja de la Armuña” showed better morphometric and nutritional characteristics than cultivars “Pardina” or “Rubia Castellana”.

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Production of Microfibrillated Cellulose from Fast-Growing Poplar and Olive Tree Pruning by Physical Pretreatment

Applied Sciences ◽

10.3390/app11146445 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6445

Author(s):

David Ibarra ◽

Raquel Martín-Sampedro ◽

Bernd Wicklein ◽

Úrsula Fillat ◽

María E. Eugenio

Keyword(s):

Negative Impact ◽

Raw Materials ◽

Olive Tree ◽

Barrier Properties ◽

Microfibrillated Cellulose ◽

Mechanical Resistance ◽

Fast Growing ◽

Wide Range ◽

Pfi Refining ◽

Tree Pruning

Motivated by the negative impact of fossil fuel consumption on the environment, the need arises to produce materials and energy from renewable sources. Cellulose, the main biopolymer on Earth, plays a key role in this context, serving as a platform for the development of biofuels, chemicals and novel materials. Among the latter, micro- and nanocellulose have been receiving increasing attention in the last few years. Their many attractive properties, i.e., thermal stability, high mechanical resistance, barrier properties, lightweight, optical transparency and ease of chemical modification, allow their use in a wide range of applications, such as paper or polymer reinforcement, packaging, construction, membranes, bioplastics, bioengineering, optics and electronics. In view of the increasing demand for traditional wood pulp (e.g., obtained from eucalypt, birch, pine, spruce) for micro/nanocellulose production, dedicated crops and agricultural residues can be interesting as raw materials for this purpose. This work aims at achieving microfibrillated cellulose production from fast-growing poplar and olive tree pruning using physical pretreatment (PFI refining) before the microfibrillation stage. Both raw materials yielded microfibrillated cellulose with similar properties to that obtained from a commercial industrial eucalypt pulp, producing films with high mechanical properties and low wettability. According to these properties, different applications for cellulose microfibers suspensions and films are discussed.

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Characterization of a Novel CaCO3-Forming Alkali-Tolerant Rhodococcus erythreus S26 as a Filling Agent for Repairing Concrete Cracks

Molecules ◽

10.3390/molecules26102967 ◽

2021 ◽

Vol 26 (10) ◽

pp. 2967

Author(s):

Seunghoon Choi ◽

Sungjin Park ◽

Minjoo Park ◽

Yerin Kim ◽

Kwang Min Lee ◽

...

Keyword(s):

Building Materials ◽

Culture Fluid ◽

Natural Phenomenon ◽

Environment Friendly ◽

Wide Range ◽

Filling Agent ◽

Calcium Source ◽

Alkali Tolerance ◽

High Alkali

Biomineralization, a well-known natural phenomenon associated with various microbial species, is being studied to protect and strengthen building materials such as concrete. We characterized Rhodococcus erythreus S26, a novel urease-producing bacterium exhibiting CaCO3-forming activity, and investigated its ability in repairing concrete cracks for the development of environment-friendly sealants. Strain S26 grown in solid medium formed spherical and polygonal CaCO3 crystals. The S26 cells grown in a urea-containing liquid medium caused culture fluid alkalinization and increased CaCO3 levels, indicating that ureolysis was responsible for CaCO3 formation. Urease activity and CaCO3 formation increased with incubation time, reaching a maximum of 2054 U/min/mL and 3.83 g/L, respectively, at day four. The maximum CaCO3 formation was achieved when calcium lactate was used as the calcium source, followed by calcium gluconate. Although cell growth was observed after the induction period at pH 10.5, strain S26 could grow at a wide range of pH 4–10.5, showing its high alkali tolerance. FESEM showed rhombohedral crystals of 20–60 µm in size. EDX analysis indicated the presence of calcium, carbon, and oxygen in the crystals. XRD confirmed these crystals as CaCO3 containing calcite and vaterite. Furthermore, R. erythreus S26 successfully repaired the artificially induced large cracks of 0.4–0.6 mm width.

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Single-nucleus chromatin accessibility and transcriptomic characterization of Alzheimer’s disease

Nature Genetics ◽

10.1038/s41588-021-00894-z ◽

2021 ◽

Author(s):

Samuel Morabito ◽

Emily Miyoshi ◽

Neethu Michael ◽

Saba Shahin ◽

Alessandra Cadete Martini ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Chromatin Accessibility ◽

Single Nucleus

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The Use of a Micro Near Infrared Portable Instrument to Predict Bioactive Compounds in a Wild Harvested Fruit—Kakadu Plum (Terminalia ferdinandiana)

Sensors ◽

10.3390/s21041413 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1413

Author(s):

Eshetu Bobasa ◽

Anh Dao T. Phan ◽

Michael Netzel ◽

Heather E. Smyth ◽

Yasmina Sultanbawa ◽

...

Keyword(s):

Vitamin C ◽

Bioactive Compounds ◽

Ellagic Acid ◽

Near Infrared ◽

Wide Range ◽

Fruit Samples ◽

Nutritional Characteristics ◽

Analytical Quantification ◽

Kakadu Plum ◽

Terminalia Ferdinandiana

Kakadu plum (KP; Terminalia ferdinandiana Exell, Combretaceae) is an emergent indigenous fruit originating from Northern Australia, with valuable health and nutritional characteristics and properties (e.g., high levels of vitamin C and ellagic acid). In recent years, the utilization of handheld NIR instruments has allowed for the in situ quantification of a wide range of bioactive compounds in fruit and vegetables. The objective of this study was to evaluate the ability of a handheld NIR spectrophotometer to measure vitamin C and ellagic acid in wild harvested KP fruit samples. Whole and pureed fruit samples were collected from two locations in the Kimberley region (Western Australia, Australia) and were analysed using both reference and NIR methods. The standard error in cross validation (SECV) and the residual predictive deviation (RPD) values were 1.81% dry matter (DM) with an RPD of 2.1, and 3.8 mg g−1 DM with an RPD of 1.9 for the prediction of vitamin C and ellagic acid, respectively, in whole KP fruit. The SECV and RPD values were 1.73% DM with an RPD of 2.2, and 5.6 mg g−1 DM with an RPD of 1.3 for the prediction of vitamin C and ellagic acid, respectively, in powdered KP samples. The results of this study demonstrated the ability of a handheld NIR instrument to predict vitamin C and ellagic acid in whole and pureed KP fruit samples. Although the RPD values obtained were not considered adequate to quantify these bioactive compounds (e.g., analytical quantification), this technique can be used as a rapid tool to screen vitamin C in KP fruit samples for high and low quality vitamin C.

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Isolation and Characterization of Strain Exiguobacterium sp. KRL4, a Producer of Bioactive Secondary Metabolites from a Tibetan Glacier

Microorganisms ◽

10.3390/microorganisms9050890 ◽

2021 ◽

Vol 9 (5) ◽

pp. 890

Author(s):

Pietro Tedesco ◽

Fortunato Palma Esposito ◽

Antonio Masino ◽

Giovanni Andrea Vitale ◽

Emiliana Tortorella ◽

...

Keyword(s):

Phenotypic Analysis ◽

Biological Assays ◽

C Elegans ◽

Isolation And Characterization ◽

Wide Range ◽

Protein Encoding ◽

Nematocidal Activity ◽

Extremophilic Microorganisms ◽

Unique Source

Extremophilic microorganisms represent a unique source of novel natural products. Among them, cold adapted bacteria and particularly alpine microorganisms are still underexplored. Here, we describe the isolation and characterization of a novel Gram-positive, aerobic rod-shaped alpine bacterium (KRL4), isolated from sediments from the Karuola glacier in Tibet, China. Complete phenotypic analysis was performed revealing the great adaptability of the strain to a wide range of temperatures (5–40 °C), pHs (5.5–8.5), and salinities (0–15% w/v NaCl). Genome sequencing identified KRL4 as a member of the placeholder genus Exiguobacterium_A and annotation revealed that only half of the protein-encoding genes (1522 of 3079) could be assigned a putative function. An analysis of the secondary metabolite clusters revealed the presence of two uncharacterized phytoene synthase containing pathways and a novel siderophore pathway. Biological assays confirmed that the strain produces molecules with antioxidant and siderophore activities. Furthermore, intracellular extracts showed nematocidal activity towards C. elegans, suggesting that strain KRL4 is a source of anthelmintic compounds.

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