scholarly journals Drosophila Immunity: Analysis of Larval Hemocytes by P-Element-Mediated Enhancer Trap

Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 623-634 ◽  
Author(s):  
Anne Braun ◽  
Bruno Lemaitre ◽  
René Lanot ◽  
Daniel Zachary ◽  
Marie Meister
Keyword(s):  
Defense Mechanisms ◽  
Tumor Formation ◽  
P Element ◽  
Lacz Expression ◽  
Hematopoietic Organ ◽  
Lymph Glands ◽  
New Genes ◽  
Tumor Phenotype ◽  
Third Line

Our aim was to identify new genes involved in the cellular aspects of defense mechanisms of Drosophila, as well as in melanotic tumor formation processes that are linked to blood cell disregulation. We have screened 1341 enhancer detector fly lines for expression of the lacZ reporter gene in larval hemocytes at the end of the third instar. We have selected 21 lines in which we observed a reproducible lacZ expression in blood cells. These lines were classified according to the subsets of hemocytes in which lacZ was expressed, and we identified five lines that can be used as lamellocyte markers. Three lines were selected for further analysis. The first exhibited strong lacZ expression in all lamellocytes. The second expressed lacZ in plasmatocytes and lamellocytes, and exhibited a melanotic tumor phenotype in larvae homozygous for the insertion. A third line showed a striking insertion-linked phenotype of melanized lymph glands (the hematopoietic organ), which resulted in the total absence of circulating hemocytes in the mutant larvae. We anticipate that this mutation, which we named domino, will prove a useful tool in the analysis of the role of hemocytes during the various aspects of immune response and melanotic tumor formation.

scholarly journals Deletion of ptn1, a PTEN/TEP1 Orthologue, in Ustilago maydis Reduces Pathogenicity and Teliospore Development

2018 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
Lalu Vijayakrishnapillai ◽  
John Desmarais ◽  
Michael Groeschen ◽  
Michael Perlin
Keyword(s):  
Defense Mechanisms ◽  
Developmental Process ◽  
Signal Transduction Pathway ◽  
Ustilago Maydis ◽  
Suppressor Gene ◽  
Tumor Formation ◽  
Proliferation And Apoptosis ◽  
Mating Efficiency ◽  
Percent Germination

The PTEN/PI3K/mTOR signal transduction pathway is involved in the regulation of biological processes such as metabolism, cell growth, cell proliferation, and apoptosis. This pathway has been extensively studied in mammals, leading to the conclusion that PTEN is a major tumor suppressor gene. PTEN orthologues have been characterized in a variety of organisms, both vertebrates and non-vertebrates, and studies of the associated PTEN/PI3K/mTOR pathway indicate that it is widely conserved. Studies in fungal systems indicated a role of PTEN in fungal defense mechanisms in Candida albicans, and in the developmental process of sporulation in Saccharomyces cerevisiae. The present study was aimed at investigating the role of the PTEN ortholog, ptn1, in Ustilago maydis, the pathogen of maize. U. maydis ptn1 mutant strains where ptn1 gene is deleted or overexpressed were examined for phenotypes associate with mating, virulence and spore formation. While the overexpression of ptn1 had no substantial effects on virulence, ptn1 deletion strains showed slight reductions in mating efficiency and significant reductions in virulence; tumor formation on stem and/or leaves were severely reduced. Moreover, tumors, when present, had significantly lower levels of mature teliospores, and the percent germination of such spores was similarly reduced. Thus, ptn1 is required for these important aspects of virulence in this fungus.

scholarly journals Identification of Immune System and Response Genes, and Novel Mutations Causing Melanotic Tumor Formation in Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 143 (2) ◽  
pp. 929-940 ◽  
Author(s):  
Antony Rodriguez ◽  
Zhijian Zhou ◽  
My Lien Tang ◽  
Steve Meller ◽  
Jiewen Chen ◽  
...  
Keyword(s):  
Immune System ◽  
Bacterial Infection ◽  
Reporter Gene ◽  
Fat Body ◽  
Infection Type ◽  
Type A ◽  
Tumor Formation ◽  
P Element ◽  
Type B ◽  
Tumor Phenotype

Abstract We are using Drosophila as a model system for analysis of immunity and tumor formation and have conducted two types of screens using enhancer detector strains to find genes related to these processes: genes expressed in the immune system (type A, hemocytes, lymph glands and fat body) and genes increased in expression by bacterial infection (type B). For type A, tissue-specific reporter gene activity was determined. For type B, a variation of enhancer detection was devised in which β-galactosidase is assayed spectrophotometrically with and without bacterial infection. Because of immune system involvement in melanotic tumor formation, a third type was hypothesized to be found among types A and B: genes that, when mutated, have a melanotic tumor phenotype. Enhancer detector strains (2800) were screened for type A, 900 for B, and 11 retained for further analysis. Complementation tests, cytological mapping, P-element mobilization, and determination of lethal phase and mutant phenotype have identified six novel genes, Dorothy, wizard, toto, Viking, Thor and dappled, and one previously identified gene, Collagen IV. All are associated with reporter gene expression in at least one immune system tissue. Thor has increased expression upon infection. Mutations of wizard and dappled have a melanotic tumor phenotype.

Potential of Mesenchymal Stem Cells in Anti-Cancer Therapies

2020 ◽  
Vol 15 (6) ◽  
pp. 482-491 ◽  
Author(s):  
Milena Kostadinova ◽  
Milena Mourdjeva
Keyword(s):  
Cancer Cells ◽  
Small Population ◽  
Tumor Formation ◽  
Bioactive Molecules ◽  
Cancer Therapies ◽  
New Methods ◽  
Cycle Arrest ◽  
Anti Cancer ◽  
Blocking Mechanisms

Mesenchymal stem/stromal cells (MSCs) are localized throughout the adult body as a small population in the stroma of the tissue concerned. In injury, tissue damage, or tumor formation, they are activated and leave their niche to migrate to the site of injury, where they release a plethora of growth factors, cytokines, and other bioactive molecules. With the accumulation of data about the interaction between MSCs and tumor cells, the dualistic role of MSCs remains unclear. However, a large number of studies have demonstrated the natural anti-tumor properties inherent in MSCs, so this is the basis for intensive research for new methods using MSCs as a tool to suppress cancer cell development. This review focuses specifically on advanced approaches in modifying MSCs to become a powerful, precision- targeted tool for killing cancer cells, but not normal healthy cells. Suppression of tumor growth by MSCs can be accomplished by inducing apoptosis or cell cycle arrest, suppressing tumor angiogenesis, or blocking mechanisms mediating metastasis. In addition, the chemosensitivity of cancer cells may be increased so that the dose of the chemotherapeutic agent used could be significantly reduced.

Role of the mitogenic property and kinase activity of p60src in tumor formation by Rous sarcoma virus.

1984 ◽  
Vol 49 (2) ◽  
pp. 325-332 ◽  
Author(s):  
F Poirier ◽  
P Jullien ◽  
P Dezelee ◽  
G Dambrine ◽  
E Esnault ◽  
...  
Keyword(s):  
Rous Sarcoma Virus ◽  
Kinase Activity ◽  
Tumor Formation ◽  
Rous Sarcoma ◽  
Sarcoma Virus

scholarly journals Genetic Studies of mei-P26 Reveal a Link Between the Processes That Control Germ Cell Proliferation in Both Sexes and Those That Control Meiotic Exchange in Drosophila

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1757-1772 ◽  
Author(s):  
Scott L Page ◽  
Kim S McKim ◽  
Benjamin Deneen ◽  
Tajia L Van Hook ◽  
R Scott Hawley
Keyword(s):  
Meiotic Recombination ◽  
Double Mutant ◽  
P Element ◽  
Genetic Studies ◽  
Germline Differentiation ◽  
Males And Females ◽  
Bag Of Marbles ◽  
Differentiation And Proliferation

Abstract We present the cloning and characterization of mei-P26, a novel P-element-induced exchange-defective female meiotic mutant in Drosophila melanogaster. Meiotic exchange in females homozygous for mei-P261 is reduced in a polar fashion, such that distal chromosomal regions are the most severely affected. Additional alleles generated by duplication of the P element reveal that mei-P26 is also necessary for germline differentiation in both females and males. To further assess the role of mei-P26 in germline differentiation, we tested double mutant combinations of mei-P26 and bag-of-marbles (bam), a gene necessary for the control of germline differentiation and proliferation in both sexes. A null mutation at the bam locus was found to act as a dominant enhancer of mei-P26 in both males and females. Interestingly, meiotic exchange in mei-P261; bamΔ86/+ females is also severely decreased in comparison to mei-P261 homozygotes, indicating that bam affects the meiotic phenotype as well. These data suggest that the pathways controlling germline differentiation and meiotic exchange are related and that factors involved in the mitotic divisions of the germline may regulate meiotic recombination.

scholarly journals ROS Defense Systems and Terminal Oxidases in Bacteria

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 839
Author(s):  
Vitaliy B. Borisov ◽  
Sergey A. Siletsky ◽  
Martina R. Nastasi ◽  
Elena Forte
Keyword(s):  
Defense Mechanisms ◽  
Protective Role ◽  
Superoxide Dismutases ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
Terminal Oxidases ◽  
Defense Systems ◽  
Respiratory Chains ◽  
Scavenging Enzymes

Reactive oxygen species (ROS) comprise the superoxide anion (O2·−), hydrogen peroxide (H2O2), hydroxyl radical (·OH), and singlet oxygen (1O2). ROS can damage a variety of macromolecules, including DNA, RNA, proteins, and lipids, and compromise cell viability. To prevent or reduce ROS-induced oxidative stress, bacteria utilize different ROS defense mechanisms, of which ROS scavenging enzymes, such as superoxide dismutases, catalases, and peroxidases, are the best characterized. Recently, evidence has been accumulating that some of the terminal oxidases in bacterial respiratory chains may also play a protective role against ROS. The present review covers this role of terminal oxidases in light of recent findings.

scholarly journals The Power of Yeast in Modelling Human Nuclear Mutations Associated with Mitochondrial Diseases

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 300
Author(s):  
Camilla Ceccatelli Berti ◽  
Giulia di Punzio ◽  
Cristina Dallabona ◽  
Enrico Baruffini ◽  
Paola Goffrini ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Mitochondrial Diseases ◽  
Yeast Saccharomyces Cerevisiae ◽  
Genome Data ◽  
New Genes ◽  
Eukaryotic Organism ◽  
Novel Variants ◽  
Therapeutic Molecules ◽  
Nuclear Mutations

The increasing application of next generation sequencing approaches to the analysis of human exome and whole genome data has enabled the identification of novel variants and new genes involved in mitochondrial diseases. The ability of surviving in the absence of oxidative phosphorylation (OXPHOS) and mitochondrial genome makes the yeast Saccharomyces cerevisiae an excellent model system for investigating the role of these new variants in mitochondrial-related conditions and dissecting the molecular mechanisms associated with these diseases. The aim of this review was to highlight the main advantages offered by this model for the study of mitochondrial diseases, from the validation and characterisation of novel mutations to the dissection of the role played by genes in mitochondrial functionality and the discovery of potential therapeutic molecules. The review also provides a summary of the main contributions to the understanding of mitochondrial diseases emerged from the study of this simple eukaryotic organism.

Identification of Chromosome Inheritance Modifiers in Drosophila melanogaster

Genetics ◽  
2001 ◽  
Vol 157 (4) ◽  
pp. 1623-1637 ◽  
Author(s):  
Kenneth W Dobie ◽  
Cameron D Kennedy ◽  
Vivienne M Velasco ◽  
Tory L McGrath ◽  
Juliani Weko ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Biological Activity ◽  
Cancer Progression ◽  
Birth Defects ◽  
Mitotic Chromosome ◽  
P Element ◽  
Inverse Pcr ◽  
Gtpase Activating Protein ◽  
New Genes ◽  
Genomic Analyses

Abstract Faithful chromosome inheritance is a fundamental biological activity and errors contribute to birth defects and cancer progression. We have performed a P-element screen in Drosophila melanogaster with the aim of identifying novel candidate genes involved in inheritance. We used a “sensitized” minichromosome substrate (J21A) to screen ∼3,000 new P-element lines for dominant effects on chromosome inheritance and recovered 78 Sensitized chromosome inheritance modifiers (Scim). Of these, 69 decreased minichromosome inheritance while 9 increased minichromosome inheritance. Fourteen mutations are lethal or semilethal when homozygous and all exhibit dramatic mitotic defects. Inverse PCR combined with genomic analyses identified P insertions within or close to genes with previously described inheritance functions, including wings apart-like (wapl), centrosomin (cnn), and pavarotti (pav). Further, lethal insertions in replication factor complex 4 (rfc4) and GTPase-activating protein 1 (Gap1) exhibit specific mitotic chromosome defects, discovering previously unknown roles for these proteins in chromosome inheritance. The majority of the lines represent mutations in previously uncharacterized loci, many of which have human homologs, and we anticipate that this collection will provide a rich source of mutations in new genes required for chromosome inheritance in metazoans.

scholarly journals Role of the V1G1 subunit of V-ATPase in breast cancer cell migration

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria De Luca ◽  
Roberta Romano ◽  
Cecilia Bucci
Keyword(s):  
Breast Cancer ◽  
Cell Migration ◽  
Cell Motility ◽  
Cancer Progression ◽  
Tumor Formation ◽  
Downstream Signaling ◽  
Late Endosomes ◽  
Intracellular Compartments

AbstractV-ATPase is a large multi-subunit complex that regulates acidity of intracellular compartments and of extracellular environment. V-ATPase consists of several subunits that drive specific regulatory mechanisms. The V1G1 subunit, a component of the peripheral stalk of the pump, controls localization and activation of the pump on late endosomes and lysosomes by interacting with RILP and RAB7. Deregulation of some subunits of the pump has been related to tumor invasion and metastasis formation in breast cancer. We observed a decrease of V1G1 and RAB7 in highly invasive breast cancer cells, suggesting a key role of these proteins in controlling cancer progression. Moreover, in MDA-MB-231 cells, modulation of V1G1 affected cell migration and matrix metalloproteinase activation in vitro, processes important for tumor formation and dissemination. In these cells, characterized by high expression of EGFR, we demonstrated that V1G1 modulates EGFR stability and the EGFR downstream signaling pathways that control several factors required for cell motility, among which RAC1 and cofilin. In addition, we showed a key role of V1G1 in the biogenesis of endosomes and lysosomes. Altogether, our data describe a new molecular mechanism, controlled by V1G1, required for cell motility and that promotes breast cancer tumorigenesis.

scholarly journals Spermine: Its Emerging Role in Regulating Drought Stress Responses in Plants

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 261
Author(s):  
Md. Mahadi Hasan ◽  
Milan Skalicky ◽  
Mohammad Shah Jahan ◽  
Md. Nazmul Hossain ◽  
Zunaira Anwar ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Responses ◽  
Abiotic Stresses ◽  
Defense Mechanisms ◽  
Antioxidant Defense ◽  
Severe Drought ◽  
New Information ◽  
Effects Of Drought

In recent years, research on spermine (Spm) has turned up a lot of new information about this essential polyamine, especially as it is able to counteract damage from abiotic stresses. Spm has been shown to protect plants from a variety of environmental insults, but whether it can prevent the adverse effects of drought has not yet been reported. Drought stress increases endogenous Spm in plants and exogenous application of Spm improves the plants’ ability to tolerate drought stress. Spm’s role in enhancing antioxidant defense mechanisms, glyoxalase systems, methylglyoxal (MG) detoxification, and creating tolerance for drought-induced oxidative stress is well documented in plants. However, the influences of enzyme activity and osmoregulation on Spm biosynthesis and metabolism are variable. Spm interacts with other molecules like nitric oxide (NO) and phytohormones such as abscisic acid, salicylic acid, brassinosteroids, and ethylene, to coordinate the reactions necessary for developing drought tolerance. This review focuses on the role of Spm in plants under severe drought stress. We have proposed models to explain how Spm interacts with existing defense mechanisms in plants to improve drought tolerance.

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