scholarly journals Development of a transformation system for Hirsutella spp. and visualization of the mode of nematode infection by GFP-labeled H. minnesotensis

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Jingzu Sun ◽  
Sook-Young Park ◽  
Seogchan Kang ◽  
Xingzhong Liu ◽  
Junzhi Qiu ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Infection Process ◽  
Whole Body ◽  
Post Inoculation ◽  
Cellular Mechanisms ◽  
C Elegans ◽  
Hirsutella Rhossiliensis ◽  
Stage Juvenile ◽  
Nematode Cuticle ◽  
Infection Processes

Abstract Hirsutella rhossiliensis and H. minnesotensis are endoparasitic fungi of the second-stage juvenile (J2) of the soybean cyst nematode (Heterodera glycines) in nature. They also parasitize both H. glycines J2 and Caenorhabditis elegans on agar plates. Agrobacterium tumefaciens-mediated transformation conditions were established for these Hirsutella spp. The resulting transformants were similar to the corresponding wild-type strains. The infection processes of H. glycines J2 and C. elegans second larval stage (L2) by H. minnesotensis expressing ZsGreen were microscopically analyzed. Conidia of H. minnesotensis adhered to passing nematodes within 8 h post-inoculation (hpi), formed an infection peg between 8 and 12 hpi and penetrated the nematode cuticle between 12 and 24 hpi for C. elegans L2 and between 12 and 32 hpi for H. glycines J2. Hyphal proliferation inside of the nematode coelom was observed at approximately 32 hpi for C. elegans L2 and at approximately 40 hpi for H. glycines J2. The fungus consumed the whole body and grew out to produce conidia at approximately 156 and 204 hpi for C. elegans L2 and H. glycines J2, respectively. The efficient transformation protocol and a better understanding of infection process provide a solid foundation for studying the molecular and cellular mechanisms underlying fungal parasitism of nematodes.

scholarly journals Predatory behaviour of trapping fungi against srf mutants of Caenorhabditis elegans and different plant and animal parasitic nematodes

Parasitology ◽  
1999 ◽  
Vol 119 (1) ◽  
pp. 95-104 ◽  
Author(s):  
P. MENDOZA DE GIVES ◽  
K. G. DAVIES ◽  
S. J. CLARK ◽  
J. M. BEHNKE
Keyword(s):  
Caenorhabditis Elegans ◽  
Infection Process ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Wild Type ◽  
Duddingtonia Flagrans ◽  
Predatory Behaviour ◽  
C Elegans ◽  
Nematode Cuticle ◽  
Predatory Response

The initial infection process of nematode-trapping fungi is based on an interaction between the trapping structure of the fungus and the surface of the nematode cuticle. A bioassay was designed to investigate the predatory response of several isolates of nematode-trapping fungi against 3 mutants of Caenorhabditis elegans (AT6, AT10 and CL261), which have been reported to differ in the reaction of their cuticle to antibodies and lectins. The bioassay was also applied to infective larvae of animal (Haemonchus contortus, Teladorsagia (Ostertagia) circumcincta and Trichostrongylus axei) and plant (Meloidogyne spp.) parasitic nematodes. Differences in trapping ability were most marked in the first 24 h, and were density dependent. Although the isolate of Arthrobotrys responded very rapidly in the first 24 h, Duddingtonia flagrans was generally the most effective isolate and Monacrosporium responded relatively poorly throughout all experiments. All the fungi tested trapped the srf mutants of C. elegans more efficiently than the wild type, and there were differences between the different srf mutants of C. elegans. Differences in trapping ability were also observed between different isolates of D. flagrans; similarly, differences in trapping behaviour were observed not only amongst the different species of plant-parasitic nematodes, but also between the sheathed and exsheathed larvae of the animal-parasitic nematodes.

A Cuticle Collagen Encoded by the lon-3 Gene May Be a Target of TGF-β Signaling in Determining Caenorhabditis elegans Body Shape

Genetics ◽  
2002 ◽  
Vol 162 (4) ◽  
pp. 1631-1639
Author(s):  
Yo Suzuki ◽  
Gail A Morris ◽  
Min Han ◽  
William B Wood
Keyword(s):  
Caenorhabditis Elegans ◽  
Body Shape ◽  
Small Body ◽  
Dependent Manner ◽  
Loss Of Function ◽  
Cellular Mechanisms ◽  
C Elegans ◽  
Gene Expression Analyses ◽  
Dose Dependent

Abstract The signaling pathway initiated by the TGF-β family member DBL-1 in Caenorhabditis elegans controls body shape in a dose-dependent manner. Loss-of-function (lf) mutations in the dbl-1 gene cause a short, small body (Sma phenotype), whereas overexpression of dbl-1 causes a long body (Lon phenotype). To understand the cellular mechanisms underlying these phenotypes, we have isolated suppressors of the Sma phenotype resulting from a dbl-1(lf) mutation. Two of these suppressors are mutations in the lon-3 gene, of which four additional alleles are known. We show that lon-3 encodes a collagen that is a component of the C. elegans cuticle. Genetic and reporter-gene expression analyses suggest that lon-3 is involved in determination of body shape and is post-transcriptionally regulated by the dbl-1 pathway. These results support the possibility that TGF-β signaling controls C. elegans body shape by regulating cuticle composition.

scholarly journals Whole-Body Regeneration in Sponges: Diversity, Fine Mechanisms, and Future Prospects

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 506
Author(s):  
Alexander Ereskovsky ◽  
Ilya E. Borisenko ◽  
Fyodor V. Bolshakov ◽  
Andrey I. Lavrov
Keyword(s):  
Single Species ◽  
Whole Body ◽  
Phylogenetic Position ◽  
Main Body ◽  
Regenerative Processes ◽  
Cellular Mechanisms ◽  
Different Types ◽  
Dissociated Cells ◽  
Shed Light ◽  
Regeneration Processes

While virtually all animals show certain abilities for regeneration after an injury, these abilities vary greatly among metazoans. Porifera (Sponges) is basal metazoans characterized by a wide variety of different regenerative processes, including whole-body regeneration (WBR). Considering phylogenetic position and unique body organization, sponges are highly promising models, as they can shed light on the origin and early evolution of regeneration in general and WBR in particular. The present review summarizes available data on the morphogenetic and cellular mechanisms accompanying different types of WBR in sponges. Sponges show a high diversity of WBR, which principally could be divided into (1) WBR from a body fragment and (2) WBR by aggregation of dissociated cells. Sponges belonging to different phylogenetic clades and even to different species and/or differing in the anatomical structure undergo different morphogeneses after similar operations. A common characteristic feature of WBR in sponges is the instability of the main body axis: a change of the organism polarity is described during all types of WBR. The cellular mechanisms of WBR are different across sponge classes, while cell dedifferentiations and transdifferentiations are involved in regeneration processes in all sponges. Data considering molecular regulation of WBR in sponges are extremely scarce. However, the possibility to achieve various types of WBR ensured by common morphogenetic and cellular basis in a single species makes sponges highly accessible for future comprehensive physiological, biochemical, and molecular studies of regeneration processes.

scholarly journals Fed-state clamp stimulates cellular mechanisms of muscle protein anabolism and modulates glucose disposal in normal men

2009 ◽  
Vol 296 (1) ◽  
pp. E105-E113 ◽  
Author(s):  
Olasunkanmi A. J. Adegoke ◽  
Stéphanie Chevalier ◽  
José A. Morais ◽  
Réjeanne Gougeon ◽  
Scot R. Kimball ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Translation Initiation ◽  
Muscle Protein ◽  
Whole Body ◽  
Glucose Disposal ◽  
Metabolic Clearance ◽  
Cellular Mechanisms ◽  
Body Protein ◽  
Fed State ◽  
Mtorc1 Signaling

Since maximum anabolism occurs postprandially, we developed a simulated fed state with clamped hyperinsulinemia, physiological hyperglycemia, and hyperaminoacidemia (Hyper-3) and explored muscle cellular mechanisms. Whole body [1-13C]leucine and [3-3H]glucose kinetics in healthy men were compared between hyperinsulinemic, euglycemic, isoaminoacidemic (Hyper-1, n = 10) and Hyper-3 ( n = 9) clamps. In Hyper-3 vs. Hyper-1, nonoxidative leucine Rd [rate of disappearance (synthesis)] was stimulated more (45 ± 4 vs. 24 ± 4 μmol/min, P < 0.01) and endogenous Ra [rate of appearance (breakdown)] was inhibited similarly; hence net balance increased more (86 ± 6 vs. 49 ± 2 μmol/min, P < 0.001). Glucose Rd was similar; thus Hyper-3 metabolic clearance rate (331 ± 23 vs. 557 ± 41 ml/min, P < 0.0005) and Rd/insulin (M, 0.65 ± 0.10 vs. 1.25 ± 0.10 mg·min−1·pmol−1·l, P < 0.001) were less, despite higher insulin (798 ± 74 vs. 450 ± 24 pmol/l, P < 0.005). In vastus lateralis muscle biopsies, phosphorylation of Akt ( P = 0.025), mammalian target of rapamycin (mTOR), ribosomal protein S6 kinase (p70S6K1; P = 0.008), S6 ( P = 0.049), and 4E-binding protein 1 (4E-BP1; P = 0.001) increased. With decreased eukaryotic initiation factor-4E (eIF4E)·4E-BP1 complex ( P = 0.01), these are consistent with increased mTOR complex 1 (mTORC1) signaling and translation initiation of protein synthesis. Although mRNA expression of ubiquitin, MAFbx 1, and MuRF-1 was unchanged, total ubiquitinated proteins decreased 20% ( P < 0.01), consistent with proteolysis suppression. The Hyper-3 clamp increases whole body protein synthesis, net anabolism, and muscle protein translation initiation pathways and decreases protein ubiquitination. The main contribution of hyperaminoacidemia is stimulation of synthesis rather than inhibition of proteolysis, and it attenuates the expected increment of glucose disposal.

scholarly journals Evaluation of Infection Processes and Resulting Disease Caused by Dendryphion penicillatum and Pleospora papaveracea on Papaver somniferum

2000 ◽  
Vol 90 (7) ◽  
pp. 699-709 ◽  
Author(s):  
Bryan A. Bailey ◽  
Patricia C. Apel-Birkhold ◽  
Nichole R. O'Neill ◽  
James Plaskowitz ◽  
Sharon Alavi ◽  
...  
Keyword(s):  
Corn Oil ◽  
Pathogenic Fungi ◽  
Infection Process ◽  
Opium Poppy ◽  
Conidial Suspension ◽  
Yield Losses ◽  
Poppy Seed ◽  
Fungal Treatment ◽  
Infection Processes ◽  
Stem Lesions

Two pathogenic fungi of opium poppy, Pleospora papaveracea and Dendryphion penicillatum, were isolated from field material in Beltsville, MD. The processes of infection by these two fungi were studied to determine the optimal environmental conditions for infection. Both fungi formed appressoria capable of penetrating directly through the plant epidermal layer. Of the two fungi, P. papaveracea was more aggressive, causing more rapid necrosis. Appressorial formation by P. papaveracea occurred as early as 4 h after application of a conidial suspension to poppy leaves. P. papaveracea formed more appressoria than did D. penicillatum, especially at cool temperatures (7 to 13°C). In greenhouse studies, P. papaveracea caused more damage to opium poppy than did D. penicillatum when applied in 10% unrefined corn oil. In the field, P. papaveracea was more consistent in its effects on opium poppy from a local seed source designated Indian Grocery. P. papaveracea caused higher disease ratings, more stem lesions, and equal or greater yield losses than did D. penicillatum on Indian Grocery. The late-maturing opium poppy variety White Cloud was severely damaged by disease, regardless of formulation or fungal treatment. P. papaveracea was the predominant fungus isolated from poppy seed capsules and the only fungus reisolated from the field the following year. These studies provide a better understanding of the infection process and the differences between these two pathogenic fungi and will be beneficial for the development of the fungi as biological control agents.

scholarly journals Assessment of Insecticide/Miticide Treatments on Soybean Cyst Nematode Bioassays Under Greenhouse Conditions

2019 ◽  
Vol 20 (2) ◽  
pp. 74-76
Author(s):  
Jordan Brungardt ◽  
Timothy C. Todd ◽  
Thomas R. Oakley ◽  
Harold N. Trick
Keyword(s):  
Soybean Cyst Nematode ◽  
Negative Impact ◽  
Basic Research ◽  
Cyst Nematode ◽  
Active Ingredients ◽  
Soybean Germplasm ◽  
Germplasm Screening ◽  
Second Stage ◽  
Stage Juvenile

The soybean cyst nematode (SCN)–soybean pathosystem is often reproduced under greenhouse conditions for basic research purposes, increasing inoculum, and soybean germplasm screening. Application of pesticides for SCN bioassays is often necessary for keeping insect and mite pest populations under control. The research presented here looks at the application of several foliar pesticides (active ingredients; abamectin, bifenthrin, clofentezine, imidacloprid, kinoprene, and pyridaben), a soil-applied imidacloprid, and combinations of pesticides on bioassays to determine if pesticide applications have a negative impact on SCN female and cyst numbers as well as egg and second-stage juvenile (J2) production, which could lead to dubious results. Results from this experiment demonstrate these chemicals can be used to control pest populations on soybean without significantly altering SCN female, cyst, egg, and J2 counts.

scholarly journals Is the Insect Cuticle the only Entry Gate for Fungal Infection? Insights into Alternative Modes of Action of Entomopathogenic Fungi

2019 ◽  
Vol 5 (2) ◽  
pp. 33 ◽  
Author(s):  
M. Constanza Mannino ◽  
Carla Huarte-Bonnet ◽  
Belén Davyt-Colo ◽  
Nicolás Pedrini
Keyword(s):  
Fungal Infection ◽  
Entomopathogenic Fungi ◽  
Fungal Pathogens ◽  
Infection Process ◽  
Integral Approach ◽  
Full Potential ◽  
Sequencing Technologies ◽  
Information Gap ◽  
Infection Processes ◽  
Fungal Genes

Entomopathogenic fungi are the only insect pathogens able to infect their host by adhesion to the surface and penetration through the cuticle. Although the possibility of fungal infection per os was described almost a century ago, there is an information gap of several decades regarding this topic, which was poorly explored due to the continuous elucidation of cuticular infection processes that lead to insect death by mycosis. Recently, with the advent of next-generation sequencing technologies, the genomes of the main entomopathogenic fungi became available, and many fungal genes potentially useful for oral infection were described. Among the entomopathogenic Hypocreales that have been sequenced, Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Cordycipitaceae) is the main candidate to explore this pathway since it has a major number of shared genes with other non-fungal pathogens that infect orally, such as Bacillus thuringiensis Berliner (Bacillales: Bacillaceae). This finding gives B. bassiana a potential advantage over other entomopathogenic fungi: the possibility to infect through both routes, oral and cuticular. In this review, we explore all known entry gates for entomopathogenic fungi, with emphasis on the infection per os. We also set out the fungal infection process in a more integral approach, as a need to exploit its full potential for insect control, considering all of its virulence factors and the conditions needed to improve its virulence against insect that might offer some resistance to the common infection through the cuticle.

Physiological effects of endogenous ouabain: control of intracellular Ca2+ stores and cell responsiveness

1993 ◽  
Vol 264 (6) ◽  
pp. C1367-C1387 ◽  
Author(s):  
M. P. Blaustein
Keyword(s):  
Steady State ◽  
Cell Types ◽  
Whole Body ◽  
Cellular Mechanisms ◽  
Signaling Mechanism ◽  
Physiological Processes ◽  
Endogenous Ouabain ◽  
Adrenal Cortical Hormone ◽  
Salt And Water Balance

Ouabain is a well-known compound but a newly discovered adrenal cortical hormone that plays a role in cell Na+ regulation and in whole body salt and water balance. Ouabain may also be a paracrine hormone and may be secreted by some central nervous system neurons as well as by other types of cells. This article focuses on the cellular mechanisms that underlie the physiological (and pathophysiological) effects of ouabain. Ouabain directly inhibits the plasmalemmal Na+ pump in a variety of cell types. Low ouabain concentrations cause, in the steady state, a modest rise in the cytosolic Na+ concentration but only a minimal decline in membrane potential. All Na+ gradient-dependent processes may thereby be affected, albeit to only a small extent. Most important, however, is the secondary redistribution of Ca2+, mediated by Na(+)-Ca2+ exchange, that should slightly increase the cytosolic free Ca2+ concentration ([Ca2+]cyt). As a result of Ca2+ sequestration in intracellular stores [the endoplasmic and/or sarcoplasmic reticulum (ER/SR)], however, a new steady state is achieved with a slightly increased [Ca2+]cyt but a substantially augmented Ca2+ store; thus the ER/SR effectively acts as a Ca2+ amplifier. This extra stored Ca2+ is then available for mobilization whenever the cells are activated. Cytosolic Ca2+ is a key signaling mechanism in virtually all cells: it controls numerous physiological processes such as contraction, secretion, and excitability. Thus ouabain may modulate cell responsiveness via its influence on ER/SR Ca2+ stores. With these principles in mind, we examine evidence that endogenous ouabain may play a role in numerous physiological and pathophysiological processes associated with altered fluid and electrolyte metabolism and deviations from the normal blood pressure-blood volume relationship. We discuss the possible participation of ouabain in the regulation of vascular tone and then consider the putative role of ouabain in several forms of hypertension, congestive heart failure, thyroid and adrenocortical dysfunction, and diabetes mellitus, as well as in the adaptation to high altitude.

scholarly journals Modulations in Gene Expression and Mapping of Genes Associated with Cyst Nematode Infection of Soybean

2001 ◽  
Vol 14 (1) ◽  
pp. 42-54 ◽  
Author(s):  
Zarir Vaghchhipawala ◽  
Ronald Bassüner ◽  
Kathryn Clayton ◽  
Kimberley Lewers ◽  
Randy Shoemaker ◽  
...  
Keyword(s):  
Gene Expression ◽  
Soybean Cyst Nematode ◽  
Genetic System ◽  
Cyst Nematode ◽  
Infection Process ◽  
Resistance Locus ◽  
Root Cells ◽  
Feeding Site ◽  
Susceptible Line ◽  
Scn Resistance

Infection of the soybean root by the soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) induces a well-documented, yet poorly understood, response by the host plant. The plant response, involving the differentiation of a feeding structure, or “syncytium,” facilitates the feeding and reproduction of the nematode to the detriment of the host. We used a genetic system involving a single dominant soybean gene conferring susceptibility to an inbred nematode strain, VL1, to characterize the nematode-host interaction in susceptible line PI 89008. The restriction fragment length polymorphism marker pB053, shown to map to a major SCN resistance locus, cosegregates with resistance among F2 progeny from the PI 89008 × PI 88287 cross. Cytological examination of the infection process confirmed that syncytium development in this genetic system is similar to that reported by others who used noninbred nematode lines. Our study of infected root tissue in the susceptible line PI 89008 revealed a number of genes enhanced in expression. Among these are catalase, cyclin, elongation factor 1α, β-1,3-endoglucanase, hydroxymethylglutaryl coenzyme A reductase, heat shock protein 70, late embryonic abundant protein 14, and formylglycinamidine ribonucleotide synthase, all of which we have genetically positioned on the public linkage map of soybean. Formylglycinamidine ribonucleotide synthase was found to be tightly linked with a major quantitative trait locus for SCN resistance. Our observations are consistent with the hypothesis proposed by others that feeding site development involves the dramatic modulation of gene expression relative to surrounding root cells.

Biochemical and cellular mechanisms regulatingAcanthamoeba castellaniiadherence to host cells

Parasitology ◽  
2013 ◽  
Vol 141 (4) ◽  
pp. 531-541 ◽  
Author(s):  
K. J. SOTO-ARREDONDO ◽  
L. L. FLORES-VILLAVICENCIO ◽  
J. J. SERRANO-LUNA ◽  
M. SHIBAYAMA ◽  
M. SABANERO-LÓPEZ
Keyword(s):  
Neuronal Cells ◽  
Acanthamoeba Castellanii ◽  
Cell Types ◽  
Infection Process ◽  
Surface Proteins ◽  
Host Cells ◽  
Epifluorescence Microscopy ◽  
Cellular Mechanisms ◽  
Cutaneous Lesions ◽  
Causative Agents

SUMMARYFree-living amoebae belonging to the genusAcanthamoebaare the causative agents of infections such as amoebic keratitis (AK), granulomatous amoebic encephalitis (GAE) and cutaneous lesions. The mechanisms involved in the establishment of infection are unknown. However, it is accepted that the initial phase of pathogenesis involves adherence to the host tissue. In this work, we analysed surface molecules with an affinity for epithelial and neuronal cells from the trophozoites ofAcanthamoeba castellanii. We also investigated the cellular mechanisms that govern the process of trophozoite adhesion to the host cells. We first used confocal and epifluorescence microscopy to examine the distribution of theA. castellaniiactin cytoskeleton during interaction with the host cells. The use of drugs, as cytochalasin B (CB) and latrunculin B (LB), revealed the participation of cytoskeletal filaments in the adhesion process. In addition, to identify the proteins and glycoproteins on the surface ofA. castellanii, the trophozoites were labelled with biotin and biotinylated lectins. The results revealed bands of surface proteins, some of which were glycoproteins with mannose andN-acetylglucosamine residues. Interaction assays of biotinylated amoebae proteins with epithelial and neuronal cells showed that some surface proteins had affinity for both cell types. The results of this study provide insight into the biochemical and cellular mechanisms of theAcanthamoebainfection process.

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