scholarly journals MUTANT GENES REGULATING THE INDUCIBILITY OF KYNURENINE SYNTHESIS

1964 ◽  
Vol 21 (2) ◽  
pp. 203-211 ◽  
Author(s):  
T. M. Rizki
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Regulation ◽  
Suppressor Gene ◽  
Culture Conditions ◽  
Cellular Level ◽  
The Body ◽  
In The Wild ◽  
A Cell ◽  
Normal Feeding ◽  
S Allele

Alterations in the cellular synthesis of kynurenine in the larval fatbody of Drosophila melanogaster may be obtained by feeding the precursor tryptophan or by changing the genotype. In the wild type Ore-R strain, autofluorescent kynurenine globules normally occur in the cells in the anterior regions of the fatbody designated as regions 1, 2, and 3. When tryptophan is included in the larval diet, kynurenine will develop throughout the entire fatbody, thus extending to the cells in regions 4, 5, and 6. In the fatbodies of both the sepia mutant strain and the mutant combinations of the suppressible vermilion alleles with the suppressor gene (su2-s, v1 and su2-s, v2), kynurenine is found in the cells from region 1 through region 4. This involvement of additional cells in the synthesis of kynurenine occurs under the usual culture conditions for Drosophila. When sepia larvae are fed tryptophan, kynurenine appears in all of the cells of the fatbody. However, dietary tryptophan does not induce kynurenine production in cells in regions 5 and 6 in the mutant combination su2-s, v1 or su2-s, v2. In the latter strains, an increase in the quantity of kynurenine in the fatbody is detected, but this increase remains limited to the same cells in which kynurenine production is found under normal feeding conditions. When the v36f allele is combined with the su2-s allele, an extremely faint autofluorescence characteristic of kynurenine is found in some of the anteriormost fat cells of regions 1 and 2. This autofluorescence becomes intensified when tryptophan is fed to su2-s, v36f larvae. The genetic control of kynurenine synthesis in the cells of the fatbody of Drosophila melanogaster has been previously demonstrated. The present observations establish genetic regulation of the ability to induce kynurenine production within a cell through the administration of the inducer tryptophan. Kynurenine production has been considered as a unit function of the cell as a whole rather than of the enzyme alone, and it has been concluded that even though cells in different parts of the body perform this same function (kynurenine production), the gene loci regulating this function may be different for cells in different regions of the body. A phenomenon of overlapping domains of gene actions at the cellular level offers a genetic and cellular basis for developmental and physiological homeostasis.

A single cell approach to problems of cell lineage and commitment during embryogenesis of Drosophila melanogaster

Development ◽  
1987 ◽  
Vol 100 (1) ◽  
pp. 1-12 ◽  
Author(s):  
G.M. Technau
Keyword(s):  
Drosophila Melanogaster ◽  
Single Cell ◽  
Cell Lineage ◽  
Cellular Level ◽  
Central Importance ◽  
Cell Level ◽  
Combined Application ◽  
A Cell ◽  
Pole Cells ◽  
Drosophila Embryos

The mechanisms leading to the commitment of a cell to a particular fate or to restrictions in its developmental potencies represent a problem of central importance in developmental biology. Both at the genetic and at the molecular level, studies addressing this topic using the fruitfly Drosophila melanogaster have advanced substantially, whereas, at the cellular level, experimental techniques have been most successfully applied to organisms composed of relatively large and accessible cells. The combined application of the different approaches to one system should improve our understanding of the process of commitment as a whole. Recently, a method has been devised to study cell lineage in Drosophila embryos at the single cell level. This method has been used to analyse the lineages, as well as the state of commitment of single cell progenitors from various ectodermal, mesodermal and endodermal anlagen and of the pole cells. The results obtained from a clonal analysis of wild-type larval structures are discussed in this review.

scholarly journals Drosophila melanogaster Responses against Entomopathogenic Nematodes: Focus on Hemolymph Clots

Insects ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 62 ◽  
Author(s):  
Alexis Dziedziech ◽  
Sai Shivankar ◽  
Ulrich Theopold
Keyword(s):  
Drosophila Melanogaster ◽  
Entomopathogenic Nematodes ◽  
Coagulation Factor ◽  
Coagulation Factors ◽  
Body Cavity ◽  
Cellular Level ◽  
Primary Phase ◽  
The Body ◽  
Infection Models ◽  
Two Phases

Several insect innate immune mechanisms are activated in response to infection by entomopathogenic nematodes (EPNs). In this review, we focus on the coagulation of hemolymph, which acts to stop bleeding after injury and prevent access of pathogens to the body cavity. After providing a general overview of invertebrate coagulation systems, we discuss recent findings in Drosophila melanogaster which demonstrate that clots protect against EPN infections. Detailed analysis at the cellular level provided insight into the kinetics of the secretion of Drosophila coagulation factors, including non-classical modes of secretion. Roughly, clot formation can be divided into a primary phase in which crosslinking of clot components depends on the activity of Drosophila transglutaminase and a secondary, phenoloxidase (PO)-dependent phase, characterized by further hardening and melanization of the clot matrix. These two phases appear to play distinct roles in two commonly used EPN infection models, namely Heterorhabditis bacteriophora and Steinernema carpocapsae. Finally, we discuss the implications of the coevolution between parasites such as EPNs and their hosts for the dynamics of coagulation factor evolution.

scholarly journals The genetics of catalase in Drosophila melanogaster: isolation and characterization of acatalasemic mutants.

Genetics ◽  
1989 ◽  
Vol 122 (3) ◽  
pp. 643-652 ◽  
Author(s):  
W J Mackay ◽  
G C Bewley
Keyword(s):  
Drosophila Melanogaster ◽  
Free Radical ◽  
Catalase Activity ◽  
Oxygen Toxicity ◽  
Threshold Effect ◽  
Culture Conditions ◽  
Free Radical Damage ◽  
Isolation And Characterization ◽  
Standard Culture ◽  
Hypomorphic Alleles

Abstract Activated oxygen species have been demonstrated to be the important agents in oxygen toxicity by disrupting the structural and functional integrity of cells through lipid peroxidation events, DNA damage and protein inactivation. The biological consequences of free radical damage have long been hypothesized to be a causal agent in many aging-related diseases. Catalase (H2O2:H2O2 oxidoreductase; EC 1.15.1.1) is one of several enzymes involved in the scavenging of oxygen free radicals and free radical derivatives. The structural gene for catalase in Drosophila melanogaster has been localized to region 75D1-76A on chromosome 3L by dosage responses to segmental aneuploidy. This study reports the isolation of a stable deficiency, Df(3L)CatDH104(75C1-2;75F1), that uncovers the catalase locus and the subsequent isolation of six acatalasemic mutants. All catalase mutants are viable under standard culture conditions and recessive lethal mutations within the 75Cl-F1 interval have been shown not to affect catalase activity. Two catalase mutations are amorphic while four are hypomorphic alleles of the Cat+ locus. The lack of intergenic complementation between the six catalase mutations strongly suggests that there is only one functional gene in Drosophila. One acatalesemic mutation was mapped to position 3-47.0 which resides within the catalase dosage sensitive region. While complete loss of catalase activity confers a severe viability effect, residual levels are sufficient to restore viability to wild type levels. These results suggest a threshold effect for viability and offer an explanation for the general lack of phenotypic effects associated with the known mammalian acatalasemics.

scholarly journals Power Failure of Mitochondria and Oxidative Stress in Neurodegeneration and Its Computational Models

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 229
Author(s):  
JunHyuk Woo ◽  
Hyesun Cho ◽  
YunHee Seol ◽  
Soon Ho Kim ◽  
Chanhyeok Park ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Dysfunction ◽  
Computational Models ◽  
Neuronal Damage ◽  
Living Organism ◽  
The Body ◽  
Mitochondrial Functions ◽  
A Cell ◽  
The Brain ◽  
And Oxidative Stress

The brain needs more energy than other organs in the body. Mitochondria are the generator of vital power in the living organism. Not only do mitochondria sense signals from the outside of a cell, but they also orchestrate the cascade of subcellular events by supplying adenosine-5′-triphosphate (ATP), the biochemical energy. It is known that impaired mitochondrial function and oxidative stress contribute or lead to neuronal damage and degeneration of the brain. This mini-review focuses on addressing how mitochondrial dysfunction and oxidative stress are associated with the pathogenesis of neurodegenerative disorders including Alzheimer’s disease, amyotrophic lateral sclerosis, Huntington’s disease, and Parkinson’s disease. In addition, we discuss state-of-the-art computational models of mitochondrial functions in relation to oxidative stress and neurodegeneration. Together, a better understanding of brain disease-specific mitochondrial dysfunction and oxidative stress can pave the way to developing antioxidant therapeutic strategies to ameliorate neuronal activity and prevent neurodegeneration.

scholarly journals Repeated stress exposure results in a survival–reproduction trade-off in Drosophila melanogaster

2009 ◽  
Vol 277 (1683) ◽  
pp. 963-969 ◽  
Author(s):  
Katie E. Marshall ◽  
Brent J. Sinclair
Keyword(s):  
Drosophila Melanogaster ◽  
Model Organism ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Stress Exposure ◽  
Trade Off ◽  
Repeated Stress ◽  
Rate Of Increase ◽  
In The Wild ◽  
Future Reproduction

While insect cold tolerance has been well studied, the vast majority of work has focused on the effects of a single cold exposure. However, many abiotic environmental stresses, including temperature, fluctuate within an organism's lifespan. Given that organisms may trade-off survival at the cost of future reproduction, we investigated the effects of multiple cold exposures on survival and fertility in the model organism Drosophila melanogaster . We found that multiple cold exposures significantly decreased mortality compared with the same length of exposure in a single sustained bout, but significantly decreased fecundity (as measured by r , the intrinsic rate of increase) as well, owing to a shift in sex ratio. This change was reflected in a long-term decrease in glycogen stores in multiply exposed flies, while a brief effect on triglyceride stores was observed, suggesting flies are reallocating energy stores. Given that many environments are not static, this trade-off indicates that investigating the effects of repeated stress exposure is important for understanding and predicting physiological responses in the wild.

scholarly journals Early Adhesion of Candida albicans onto Dental Acrylic Surfaces

2017 ◽  
Vol 96 (8) ◽  
pp. 917-923 ◽  
Author(s):  
S. Aguayo ◽  
H. Marshall ◽  
J. Pratten ◽  
D. Bradshaw ◽  
J.S. Brown ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Clinical Isolate ◽  
Force Spectroscopy ◽  
Laboratory Strain ◽  
Culture Conditions ◽  
The Body ◽  
Yeast Cells ◽  
Adhesion Forces ◽  
Reliable Technique ◽  
Mother Cells

Denture-associated stomatitis is a common candidal infection that may give rise to painful oral symptoms, as well as be a reservoir for infection at other sites of the body. As poly (methyl methacrylate) (PMMA) remains the main material employed in the fabrication of dentures, the aim of this research was to evaluate the adhesion of Candida albicans cells onto PMMA surfaces by employing an atomic force microscopy (AFM) single-cell force spectroscopy (SCFS) technique. For experiments, tipless AFM cantilevers were functionalized with PMMA microspheres and probed against C. albicans cells immobilized onto biopolymer-coated substrates. Both a laboratory strain and a clinical isolate of C. albicans were used for SCFS experiments. Scanning electron microscopy (SEM) and AFM imaging of C. albicans confirmed the polymorphic behavior of both strains, which was dependent on growth culture conditions. AFM force-spectroscopy results showed that the adhesion of C. albicans to PMMA is morphology dependent, as hyphal tubes had increased adhesion compared with yeast cells ( P < 0.05). C. albicans budding mother cells were found to be nonadherent, which contrasts with the increased adhesion observed in the tube region. Comparison between strains demonstrated increased adhesion forces for a clinical isolate compared with the lab strain. The clinical isolate also had increased survival in blood and reduced sensitivity to complement opsonization, providing additional evidence of strain-dependent differences in Candida-host interactions that may affect virulence. In conclusion, PMMA-modified AFM probes have shown to be a reliable technique to characterize the adhesion of C. albicans to acrylic surfaces.

Identity of the Distal Segments of the Maxilla 2 and Maxilliped in Copepods: New Teeth for Carl Claus' Old Saw

Crustaceana ◽  
1995 ◽  
Vol 68 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Frank D. Ferrari
Keyword(s):  
Genetic Regulation ◽  
The Body ◽  
Developmental Pattern ◽  
General Hypothesis

AbstractInterpretations by Claus and Gicsbrecht of the identity of the distal segments of the maxilla 2 and maxilliped in copepods are reviewed. The developmental pattern of setal additions to these appendages suggests that the distal segments of maxilla 2 are exopodal, while those of the maxilliped are endopodal; these data are consistent with the interpretation of Claus. Information about the genetic regulation of development of a fruitfly, and a reinterpretation of a fossil arthropod also support Claus. A general hypothesis identifies a compartment with a contralateral pair of uniramal limbs as the basic division of the body of an ancestral arthropod. Somites, crustacean biramal appendages, and insect uniramal appendages arc derived. The general hypothesis is used to explain the structure of a copepod including maxilla 2 and maxilliped.

scholarly journals Magnitude integration in the Archerfish

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tali Leibovich-Raveh ◽  
Ashael Raveh ◽  
Dana Vilker ◽  
Shai Gabay
Keyword(s):  
Animal Model ◽  
Grocery Store ◽  
The Body ◽  
Water Tank ◽  
Comparison Task ◽  
Magnitude Comparison ◽  
Mathematical Abilities ◽  
In The Wild ◽  
Numerical Magnitudes ◽  
Shortest Queue

AbstractWe make magnitude-related decisions every day, for example, to choose the shortest queue at the grocery store. When making such decisions, which magnitudes do we consider? The dominant theory suggests that our focus is on numerical quantity, i.e., the number of items in a set. This theory leads to quantity-focused research suggesting that discriminating quantities is automatic, innate, and is the basis for mathematical abilities in humans. Another theory suggests, instead, that non-numerical magnitudes, such as the total area of the compared items, are usually what humans rely on, and numerical quantity is used only when required. Since wild animals must make quick magnitude-related decisions to eat, seek shelter, survive, and procreate, studying which magnitudes animals spontaneously use in magnitude-related decisions is a good way to study the relative primacy of numerical quantity versus non-numerical magnitudes. We asked whether, in an animal model, the influence of non-numerical magnitudes on performance in a spontaneous magnitude comparison task is modulated by the number of non-numerical magnitudes that positively correlate with numerical quantity. Our animal model was the Archerfish, a fish that, in the wild, hunts insects by shooting a jet of water at them. These fish were trained to shoot water at artificial targets presented on a computer screen above the water tank. We tested the Archerfish's performance in spontaneous, untrained two-choice magnitude decisions. We found that the fish tended to select the group containing larger non-numerical magnitudes and smaller quantities of dots. The fish selected the group containing more dots mostly when the quantity of the dots was positively correlated with all five different non-numerical magnitudes. The current study adds to the body of studies providing direct evidence that in some cases animals’ magnitude-related decisions are more affected by non-numerical magnitudes than by numerical quantity, putting doubt on the claims that numerical quantity perception is the most basic building block of mathematical abilities.

Development of surface pattern during division in Paramecium. II. Defective spatial control in the mutant kin241

Development ◽  
1992 ◽  
Vol 115 (1) ◽  
pp. 319-335 ◽  
Author(s):  
M. Jerka-Dziadosz ◽  
N. Garreau de Loubresse ◽  
J. Beisson
Keyword(s):  
Basal Body ◽  
Major Effect ◽  
The Body ◽  
Cortical Reorganization ◽  
Surface Pattern ◽  
Recessive Mutation ◽  
Wild Type ◽  
Cortical Organization ◽  
Nuclear Reorganization ◽  
In The Wild

kin241 is a monogenic nuclear recessive mutation producing highly pleiotropic effects on cell size and shape, generation time, thermosensitivity, nuclear reorganization and cortical organization. We have analyzed the nature of the cortical disorders and their development during division, using various specific antibodies labelling either one of the cortical cytoskeleton components, as was previously done for analysis of cortical pattern formation in the wild type. Several abnormalities in basal body properties were consistently observed, although with a variable frequency: extra microtubules in either the triplets or in the lumen; nucleation of a second kinetodesmal fiber; abnormal orientation of the newly formed basal body with respect to the mother one. The latter effect seems to account for the major observed cortical disorders (reversal, intercalation of supplementary ciliary rows). The second major effect of the mutation concerns the spatiotemporal map of cortical reorganization during division. Excess basal body proliferation occurs and is correlated with modified boundaries of some of the cortical domains identified in the wild type on the basis of their basal body duplication pattern. This is the first mutant described in a ciliate in which both the structure and duplication of basal bodies and the body plan are affected. The data support the conclusion that the mutation does not alter the nature of the morphogenetic signal(s) which pervade the dividing cell, nor the competence of cytoskeletal structures to respond to signalling, but affects the local interpretation of the signals.

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