scholarly journals ADAPTIVE SIGNIFICANCE OF VEGETATIVE INCOMPATIBILITY IN NEUROSPORA CRASSA

Genetics ◽  
1975 ◽  
Vol 81 (3) ◽  
pp. 553-569
Author(s):  
Daniel L Hartl ◽  
Everett R Dempster ◽  
Spencer W Brown
Keyword(s):  
Mathematical Model ◽  
Life Cycle ◽  
Neurospora Crassa ◽  
Filamentous Fungi ◽  
Adaptive Significance ◽  
Vegetative Incompatibility ◽  
Selection Pressures ◽  
Proliferative Advantage

ABSTRACT Certain features reminiscent of sexuality occur in the vegetative life cycle of some filamentous fungi such as Neurospora crassa. Hyphal fusions can occur between genetically different individuals, thereby endowing the new composite mycelium, a heterokaryon, with some of the advantages of heterozygosity usually associated with diploid organisms. In N. crassa, however, there are a number of incompatibility loci which prevent formation of heterokaryons unless the alleles at the incompatibility loci are identical in the two mycelia. The selection pressures that maintain incompatibility polymorphisms are not known. We suggest here that they are maintained because they prevent a kind of exploitation of heterokaryons by nuclei that are nonadaptive in homokaryons but that enjoy a proliferative advantage over other nuclei in heterokaryons. A mathematical model that abstracts the major features of the vegetative life cycle of Neurosopra crassa has been developed, and the action of selection in this model and various extensions of it is such as to maintain polymorphisms of vegetative incompatibility factors.

scholarly journals The ham-2 Locus, Encoding a Putative Transmembrane Protein, Is Required for Hyphal Fusion in Neurospora crassa

Genetics ◽  
2002 ◽  
Vol 160 (1) ◽  
pp. 169-180
Author(s):  
Qijun Xiang ◽  
Carolyn Rasmussen ◽  
N Louise Glass
Keyword(s):  
Neurospora Crassa ◽  
Somatic Cell ◽  
Molecular Mechanism ◽  
Cell Fusion ◽  
Deletion Mutant ◽  
Transmembrane Protein ◽  
Wild Type ◽  
Vegetative Incompatibility ◽  
Hyphal Fusion ◽  
Aerial Hyphae

Abstract Somatic cell fusion is common during organogenesis in multicellular eukaryotes, although the molecular mechanism of cell fusion is poorly understood. In filamentous fungi, somatic cell fusion occurs during vegetative growth. Filamentous fungi grow as multinucleate hyphal tubes that undergo frequent hyphal fusion (anastomosis) during colony expansion, resulting in the formation of a hyphal network. The molecular mechanism of the hyphal fusion process and the role of networked hyphae in the growth and development of these organisms are unexplored questions. We use the filamentous fungus Neurospora crassa as a model to study the molecular mechanism of hyphal fusion. In this study, we identified a deletion mutant that was restricted in its ability to undergo both self-hyphal fusion and fusion with a different individual to form a heterokaryon. This deletion mutant displayed pleiotropic defects, including shortened aerial hyphae, altered conidiation pattern, female sterility, slow growth rate, lack of hyphal fusion, and suppression of vegetative incompatibility. Complementation with a single open reading frame (ORF) within the deletion region in this mutant restored near wild-type growth rates, female fertility, aerial hyphae formation, and hyphal fusion, but not vegetative incompatibility and wild-type conidiation pattern. This ORF, which we named ham-2 (for hyphal anastomosis), encodes a putative transmembrane protein that is highly conserved, but of unknown function among eukaryotes.

A multi-objective model for sustainable closed-loop supply chain of perishable products under two carbon emission regulations

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Saman Esmaeilian ◽  
Dariush Mohamadi ◽  
Majid Esmaelian ◽  
Mostafa Ebrahimpour
Keyword(s):  
Mathematical Model ◽  
Supply Chain ◽  
Life Cycle ◽  
Carbon Emission ◽  
Closed Loop ◽  
Perishable Products ◽  
Supply Chain Network ◽  
Closed Loop Supply Chain ◽  
Content Type ◽  
Trade Model

Purpose This paper aims to minimize the total carbon emissions and costs and also maximize the total social benefits. Design/methodology/approach The present study develops a mathematical model for a closed-loop supply chain network of perishable products so that considers the vital aspects of sustainability across the life cycle of the supply chain network. To evaluate carbon emissions, two different regulating policies are studied. Findings According to the obtained results, increasing the lifetime of the perishable products improves the incorporated objective function (IOF) in both the carbon cap-and-trade model and the model with a strict cap on carbon emission while the solving time increases in both models. Moreover, the computational efficiency of the carbon cap-and-trade model is higher than that of the model with a strict cap, but its value of the IOF is worse. Results indicate that efficient policies for carbon management will support planners to achieve sustainability in a cost-effectively manner. Originality/value This research proposes a mathematical model for the sustainable closed-loop supply chain of perishable products that applies the significant aspects of sustainability across the life cycle of the supply chain network. Regional economic value, regional development, unemployment rate and the number of job opportunities created in the regions are considered as the social dimension.

Synchronizing the Neurospora crassa circadian clock with the rhythmic environment

2005 ◽  
Vol 33 (5) ◽  
pp. 949-952 ◽  
Author(s):  
N. Price-Lloyd ◽  
M. Elvin ◽  
C. Heintzen
Keyword(s):  
Light Intensity ◽  
Circadian Clock ◽  
Neurospora Crassa ◽  
Model Organism ◽  
Circadian Clocks ◽  
Current Understanding ◽  
Signalling Pathways ◽  
Selection Pressures ◽  
The Earth ◽  
Natural Cycles

The metronomic predictability of the environment has elicited strong selection pressures for the evolution of endogenous circadian clocks. Circadian clocks drive molecular and behavioural rhythms that approximate the 24 h periodicity of our environment. Found almost ubiquitously among phyla, circadian clocks allow preadaptation to rhythms concomitant with the natural cycles of the Earth. Cycles in light intensity and temperature for example act as important cues that couple circadian clocks to the environment via a process called entrainment. This review summarizes our current understanding of the general and molecular principles of entrainment in the model organism Neurospora crassa, a simple eukaryote that has one of the best-studied circadian systems and light-signalling pathways.

scholarly journals Impact of Generational Commonality of Short-Life Cycle Products in Manufacturing and Remanufacturing Processes

2019 ◽  
Vol 1 (1) ◽  
pp. 3331-3340
Author(s):  
Jinju Kim ◽  
Harrison Kim
Keyword(s):  
Mathematical Model ◽  
Life Cycle ◽  
Utilization Rate ◽  
Pricing Strategies ◽  
Performance Difference ◽  
Short Life ◽  
Optimal Production ◽  
Short Life Span ◽  
New Generation ◽  
Short Life Cycle Products

AbstractShort-life cycle products are frequently replaced and discarded despite being resource-intensive. The short life span and the low utilization rate of the end-of-life products cause severe environmental problems and waste of resources. In the case of short-life cycle products, a new generation of products is released sooner than other products, therefore there are the opportunities to have various generations of products during the remanufacturing process. The commonality between generations increases the intergenerational component compatibility, which increases the efficiency of the manufacturing and remanufacturing processes, while at the same time weakening the performance difference between generations. This paper proposes a mathematical model to investigate the effect of commonality among generations on the overall production process. Based on various given new generation product designs with different commonality, we aim to propose optimal production planning and pricing strategies to maximize the total profitability and investigate how the results vary according to the commonality strategies between product generations.

Vegetative incompatibility in filamentous fungi: het genes begin to talk

1994 ◽  
Vol 10 (12) ◽  
pp. 441-446 ◽  
Author(s):  
Joel Bégueret ◽  
Béatrice Turcq ◽  
Corinne Clavé
Keyword(s):  
Filamentous Fungi ◽  
Vegetative Incompatibility

Characterization of Ctr family genes and the elucidation of their role in the life cycle of Neurospora crassa

2010 ◽  
Vol 47 (3) ◽  
pp. 237-245 ◽  
Author(s):  
Premsagar Korripally ◽  
Anand Tiwari ◽  
Adhikarla Haritha ◽  
Patnala Kiranmayi ◽  
Manjula Bhanoori
Keyword(s):  
Life Cycle ◽  
Neurospora Crassa

scholarly journals VIB-1 Is Required for Expression of Genes Necessary for Programmed Cell Death in Neurospora crassa

2006 ◽  
Vol 5 (12) ◽  
pp. 2161-2173 ◽  
Author(s):  
Karine Dementhon ◽  
Gopal Iyer ◽  
N. Louise Glass
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Neurospora Crassa ◽  
Filamentous Fungi ◽  
Somatic Growth ◽  
Genetic Differences ◽  
Extracellular Proteases ◽  
Hyphal Fusion ◽  
Expression Of Genes ◽  
Nonself Recognition

ABSTRACT Nonself recognition during somatic growth is an essential and ubiquitous phenomenon in both prokaryotic and eukaryotic species. In filamentous fungi, nonself recognition is also important during vegetative growth. Hyphal fusion between genetically dissimilar individuals results in rejection of heterokaryon formation and in programmed cell death of the fusion compartment. In filamentous fungi, such as Neurospora crassa, nonself recognition and heterokaryon incompatibility (HI) are regulated by genetic differences at het loci. In N. crassa, mutations at the vib-1 locus suppress nonself recognition and HI mediated by genetic differences at het-c/pin-c, mat, and un-24/het-6. vib-1 is a homolog of Saccharomyces cerevisiae NDT80, which is a transcriptional activator of genes during meiosis. For this study, we determined that vib-1 encodes a nuclear protein and showed that VIB-1 localization varies during asexual reproduction and during HI. vib-1 is required for the expression of genes involved in nonself recognition and HI, including pin-c, tol, and het-6; all of these genes encode proteins containing a HET domain. vib-1 is also required for the production of downstream effectors associated with HI, including the production of extracellular proteases upon carbon and nitrogen starvation. Our data support a model in which mechanisms associated with starvation and nonself recognition/HI are interconnected. VIB-1 is a major regulator of responses to nitrogen and carbon starvation and is essential for the expression of genes involved in nonself recognition and death in N. crassa.

scholarly journals Mathematical modeling of emergency situations at objects of production and gas transportation

2018 ◽  
Vol 251 ◽  
pp. 04012 ◽  
Author(s):  
Victor Orlov ◽  
Elena Detina ◽  
Oleg Kovalchuk
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Life Cycle ◽  
Real Life ◽  
Functional Safety ◽  
Emergency Situations ◽  
Managerial Decisions ◽  
Management Of Resources ◽  
Rational Management ◽  
The Mathematical Model

Mathematical modeling attracts the attention of researchers from different fields, as one of the rigorous methods of justifying the conducted researchs. Mathematical modeling makes it possible forecast to real life situations. Based on the mathematical model, the work provides the innovative recommendations for making managerial decisions on increasing the reliability and functional safety of the pipeline at all stages of its life cycle. The results obtained allow: 1) to consider issues related to the rational management of resources for the maintenance of the infrastructure of gas chemical complexes in conditions of limited means; 2) is have adapt RAMS methodology to the complex of Russian standards and the base of normative and methodological documentation on managing the life cycle processes of systems of to product and transportat of gas.

scholarly journals Defining individual size in the model filamentous fungus Neurospora crassa

2016 ◽  
Vol 283 (1826) ◽  
pp. 20152470 ◽  
Author(s):  
Linda Ma ◽  
Boya Song ◽  
Thomas Curran ◽  
Nhu Phong ◽  
Emilie Dressaire ◽  
...  
Keyword(s):  
Neurospora Crassa ◽  
Filamentous Fungi ◽  
Filamentous Fungus ◽  
Reproductive Potential ◽  
Fungal Mycelium ◽  
Dependent Property ◽  
Mycelial Network ◽  
And Function ◽  
Individual Size ◽  
Over Time

It is challenging to apply the tenets of individuality to filamentous fungi: a fungal mycelium can contain millions of genetically diverse but totipotent nuclei, each capable of founding new mycelia. Moreover, a single mycelium can potentially stretch over kilometres, and it is unlikely that its distant parts share resources or have the same fitness. Here, we directly measure how a single mycelium of the model ascomycete Neurospora crassa is patterned into reproductive units (RUs), meaning subpopulations of nuclei that propagate together as spores, and function as reproductive individuals. The density of RUs is sensitive to the geometry of growth; we detected 50-fold smaller RUs when mycelia had expanding frontiers than when they were constrained to grow in one direction only. RUs fragmented further when the mycelial network was perturbed. In mycelia with expanding frontiers, RU composition was strongly influenced by the distribution of genotypes early in development. Our results provide a concept of fungal individuality that is directly connected to reproductive potential, and therefore to theories of how fungal individuals adapt and evolve over time. Our data show that the size of reproductive individuals is a dynamic and environment-dependent property, even within apparently totally connected fungal mycelia.

scholarly journals Making two organelles from one: Woronin body biogenesis by peroxisomal protein sorting

2008 ◽  
Vol 180 (2) ◽  
pp. 325-339 ◽  
Author(s):  
Fangfang Liu ◽  
Seng Kah Ng ◽  
Yanfen Lu ◽  
Wilson Low ◽  
Julian Lai ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Neurospora Crassa ◽  
Filamentous Fungi ◽  
Dense Core ◽  
Cell Cortex ◽  
Protein Matrix ◽  
Woronin Body ◽  
Membrane Bound ◽  
And Control ◽  
Dual Functions

Woronin bodies (WBs) are dense-core organelles that are found exclusively in filamentous fungi and that seal the septal pore in response to wounding. These organelles consist of a membrane-bound protein matrix comprised of the HEX protein and, although they form from peroxisomes, their biogenesis is poorly understood. In Neurospora crassa, we identify Woronin sorting complex (WSC), a PMP22/MPV17-related membrane protein with dual functions in WB biogenesis. WSC localizes to large peroxisome membranes where it self-assembles into detergent-resistant oligomers that envelop HEX assemblies, producing asymmetrical nascent WBs. In a reaction requiring WSC, these structures are delivered to the cell cortex, which permits partitioning of the nascent WB and WB inheritance. Our findings suggest that WSC and HEX collaborate and control distinct aspects of WB biogenesis and that cortical association depends on WSC, which in turn depends on HEX. This dependency helps order events across the organellar membrane, permitting the peroxisome to produce a second organelle with a distinct composition and intracellular distribution.

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