scholarly journals Effect of lead on polytenic chromosomes from salivary glands of Chironomus Plumosus L. and Glyptotendipes Glaucus Mg. (Diptera, Chironomidae)

2019 ◽  
Vol 17 (2) ◽  
pp. 55-62
Author(s):  
Yulia V. Belonogova ◽  
Natalia A. Durnova ◽  
Anna S. Sheremetyeva
Keyword(s):  
Protein Biosynthesis ◽  
Lead Nitrate ◽  
Polytene Chromosomes ◽  
Nucleolus Organizer ◽  
Experimental Conditions ◽  
Functional Changes ◽  
Activity Factor ◽  
Genetic Activity ◽  
Mechanisms Of Adaptation ◽  
Glyptotendipes Glaucus

Background. Experimental conditions allow to determine the structural and functional changes of polytene chromosomes under the influence of free ions of an individual metal. Materials and methods. C. plumosus (L.) and G. glaucus (Mg) larvae were placed in solutions of lead nitrate: 0.01, 0.02, 0.1 and 0.5 mg/l. Exposure 12 h. Analysis of preparations of polytene chromosomes was carried out using the Carl Zeiss PrimoStar microscope. The functional activity factor of the nucleolus organizer (NOR), the coefficient of genetic activity of the Balbiani ring (BRR) was calculated. Results. Equations of the dependence of the change in the coefficients: NOR = 5,1870,01 lnC for C. plumosus and NOR = 2,110,03 lnC for G. glaucus; BRR = 1,5040,04 lnC for C. plumosus and BRR = 2,018 + 0,03 lnC for G. glaucus. Conclusion. With an increase in the concentration of lead in both C. plumosus and G. glaucus decreases NOR, which implies a decrease in the intensity of protein biosynthesis processes. BRR decreases in C. plumosus and increases in G. glaucus. The different genome reactions of the two species indicate the existence of different mechanisms of adaptation to lead ions

POLYTENE CHROMOSOMES OF GLYPTOTENDIPES GLAUCUS MG. (DIPTERA, CHIRONOMIDAE) AS TEST – OBJEKT TO STUDY TOXIC EFFECTS OF LEAD IONS

2017 ◽  
pp. 35-39
Author(s):  
N. A. Durnova ◽  
Y. V. Klimovа ◽  
M. Y. Voronin
Keyword(s):  
Nitrate Solution ◽  
Lead Nitrate ◽  
Polytene Chromosomes ◽  
Nucleolar Organizer ◽  
Solution Concentration ◽  
Lead Ions ◽  
Balbiani Ring ◽  
Genetic Activity ◽  
Compactness Index ◽  
Glyptotendipes Glaucus

Results of the analysis of cytogenetic effects of lead ions on polytene chromosomes of Glyptotendipes glaucus Mg are reported. The functional state of polytene chromosomes was determined via computation: chromosome compactness index (CR); coefficient of genetic activity of the nucleolar organizer (NOR) and coefficient of genetic activity of the Balbiani ring (BR). With increase of the lead nitrate solution concentration, the compactness index increases, that is, the chromosomes compactness decreases: medians of CR values (when measuring shoulder E) in the control are 6.05, for the maximum concentration studied they are 7.3. As a result of the of lead ions action, the activity of the nucleolar organizer genes decreases: medians of the NOR values decrease from 2.3 in the control to 2.0 for the highest concentrations used in the experiment. The activity of the Balbiani ring genes increases with the growing concentration of the lead nitrate solution: medians of the BR values in the control are 1.45, for the maximum studied concentration they are 1.95. The G. glaucus genome responds ambiguously to the change in the lead ions concentration in the medium: the coefficient of the nucleolar organizer’s genetic activity decreases, while the genetic activity of the Balbiani ring, on the contrary, increases.

scholarly journals Reversibility of acid and alkaline deoxyribonuclease deficiency in malignant tumor cells.

1981 ◽  
Vol 29 (9) ◽  
pp. 1053-1060 ◽  
Author(s):  
H S Taper
Keyword(s):  
Tumor Cells ◽  
Malignant Tumor ◽  
Tumor Necrosis ◽  
Lead Nitrate ◽  
Dnase Activity ◽  
Masking Effect ◽  
Experimental Conditions ◽  
Early Stages ◽  
Acid Dnase

The nature of DNAse deficiency, which appears to be characteristic for malignant tumor cells, was investigated by the histochemical lead nitrate technique under various experimental conditions. Reappearance of distinct alkaline and acid DNAse activity was observed on the periphery of spontaneously occurring tumor necrosis, at early stages of the in vitro induced tumor necrosis, in necrotic tumor cells after in vivo irradiation and after in vitro treatment with different compounds. A membrane releaser did not reactivate DNAses in viable tumor cells, whereas the homogenate from tumor tissue inhibited DNAses in normal rat liver. These findings indicate that alkaline and acid DNAse deficiency in malignant tumor cells is a reversible phenomenon. This reversal of enzymatic activity has different histochemical and chronological patterns and specific reactivating factors for each DNAse. The masking effect of DNAse activity in malignant tumor cells is probably linked to natural enzyme inhibitors and its reversal to early stages of tumor necrosis.

scholarly journals Peculiarities of choromosomal polymorphism Glyptotendipes glaucus meigen, 1818 (Diptera, Chironomidae) from lake Chaika of the national park “Curonian spit”

2017 ◽  
Vol 15 (3) ◽  
pp. 27-33
Author(s):  
Evgeniya A. Kalinina ◽  
Natalya V. Vinokurova
Keyword(s):  
National Park ◽  
Polytene Chromosomes ◽  
Chromosome Mapping ◽  
Total Biomass ◽  
Collection Site ◽  
Curonian Spit ◽  
Widespread Species ◽  
Kaliningrad Region ◽  
Chromosome Iii ◽  
Glyptotendipes Glaucus

Background. The genus Glyptotendipes includes widespread species of chironomids with the largest phytophilous larvae, which constitute a large percentage of the total biomass of invertebrates. Glyptotendipes glaucus (Meigen, 1818) is the dominant species of chironomids in Lake Chaika of the National Park “Curonian Spit”. Materials and methods. The material of the study included 51 Glyptotendipes glaucus fourth – instar larvae collected in Lake Chaika of the National Park “Curonian Spit”. Larvae were fixed in Carnoy’s liquid (ethanol : glacial acetic acid = 3 : 1) at the collection site. The slides of polytene chromosomes from salivary glands of the larvae were prepared according to the standard aceto – orsein technique. Chromosome mapping was carried out according to Belyanina and Durnova (1998). Results. The level of inversion polymorphism for given populations was determined. Two new inversion sequences glaD6 and glaD7 were detected and localized. Ectopic contact type of T-T between the chromosome G(IV) and the arm of F(III), as well as the monomorphy of the chromosome III(EF) Glyptotendipes glaucus were first identified in the Kaliningrad region. The value of the ratio of the number of inversion sequences to the number of genomic combinations corresponded to its level for previously studied reservoirs in Kaliningrad city. Conclusion. The prevalence of the inversion sequences glaA2, glaA3, glaB2 glaB3, glaB4, glaB6, glaC3, glaD2, glaD3, glaD5, glaG4 in chromosomes I(AB), II(CD) and IV(G) Glyptotendipes glaucus of Lake Chaika indicates the greatest variability and dynamism of this parts of the genome of the species.

scholarly journals A Physiological behavior and tolerance of Lactuca sativa to lead nitrate and silver nitrate heavy metals

2022 ◽  
Vol 82 ◽  
Author(s):  
J. D. O. Santos ◽  
E.S. Silva ◽  
P. Silva ◽  
M. A. C. Silva ◽  
L. A. Santos ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Silver Nitrate ◽  
Lactuca Sativa ◽  
Lead Nitrate ◽  
Photosynthetic Apparatus ◽  
Seed Vigor ◽  
National Council ◽  
Initial Growth ◽  
Arable Soils ◽  
Experimental Conditions

Abstract This study goal to evaluate the effects of different concentrations of lead (Pb) and silver (Ag) on germination, initial growth and anatomical alterations of Lactuca sativa L. Plants use various mechanisms to reduce the impacts caused by anthropic action, such as xenobiotic elements of soils and water contaminated by heavy metals. These metals were supplied as lead nitrate and silver nitrate and the following treatments were established: control for both metals, maximum dose of heavy metals, for arable soils, allowed by the National Council of the Environment (Ag = 25 mg. Kg-1, Pb = 180 mg. Kg-1), double (Ag = 50 mg. Kg-1, Pb = 360 mg. Kg-1) and triple (Ag = 75 mg. Kg-1, Pb = 540 mg. Kg -1) of this dosage. Vigor and germination tests of the seeds and possible anatomical changes in the leaves and roots of lettuce plants were performed. The species showed a high capacity to germinate under Pb and Ag stress, and the germination was never completely inhibited; however, the germination decreased with increasing Pb concentrations, but not under Ag stress. The use of increasing doses of metals reduced seed vigor and increased chlorophyll content. An increase in biomass was also observed in plants from treatments submitted to Pb. The phytotoxic effects of metals were more pronounced at 15 days after sowing. Anatomically, L. sativa was influenced by metal concentrations, and had a reduction of up to 79.9% in root epidermis thickness at the highest Pb concentration, although some structures did not suffer significant changes. The results suggest that L. sativa presents tolerance to high concentrations of heavy metals, showing possible mechanisms to overcome the stress caused by these metals. In this research lettuce possibly used the mechanism of exclusion of metals retaining Pb and Ag in the roots preserving the photosynthetic apparatus in the aerial part of the plants. In general, the chemical element Pb was more toxic than Ag, in these experimental conditions.

scholarly journals Physicochemical characteristics of the Dombrovska pit lake (Ukraine) formed in an opencast potassium salt mine and the genome response of Chironomus salinarius Kieffer (Chironomidae, Diptera) to these conditions

2020 ◽  
Vol 28 (1) ◽  
pp. 446-458
Author(s):  
Paraskeva Michailova ◽  
Ewa Szarek-Gwiazda ◽  
Andrzej Kownacki
Keyword(s):  
Potassium Salt ◽  
Major Ions ◽  
Genome Instability ◽  
Polytene Chromosomes ◽  
Benthic Fauna ◽  
Nucleolar Organizer ◽  
Salt Mine ◽  
Pit Lake ◽  
Functional Changes ◽  
Chironomus Salinarius

AbstractThis study focuses on the Dombrovska pit lake, near the city of Kalush in Ukraine, which is a former potassium salt mine filled with brine and freshwater. The water level is still increasing and as a result the salinity is decreasing. We analyzed the benthic fauna communities and the genome instability by assessing the rearrangements in the polytene chromosomes of Chironomus salinarius and the physicochemical parameters of the near-bottom water (pH, conductivity, mineralization, major ions, NO3−, NH4+, metals Cd, Pb, Cu, Mn, and Fe) and sediment (pH, organic matter and metals Cd, Pb, Cu, Zn, Mn, and Fe) at four sites. The water mineralization ranged from 17.3 to 26.2 g dm−3 which are classified as mesohaline and polyhaline waters, respectively. The biodiversity of the benthic fauna was low, and the dominant species was C. salinarius. The density of C. salinarius varied spatially and changed from 637 ind./m2 at a depth of 5 m to 8167 ind./m2 at a depth of 2.5 m. The genome instability was analyzed by examining the structural and functional changes in the salivary gland chromosomes of C. salinarius. The exposure of C. salinarius damaged the chromosomes and the activities of key structures, such as the Balbiani ring and nucleolar organizer, were partially or completely suppressed.

The role of hypoxia in the integrity of the genetic apparatus and the formation of memory in drosophila in the paradigm of conditioned reflex suppression of courtship

2021 ◽  
Vol 20 (4) ◽  
pp. 45-54
Author(s):  
Anna V. Medvedeva ◽  
Elena V. Tokmacheva ◽  
Ekaterina A. Nikitina ◽  
Svetlana Alexandrovna Vasilieva ◽  
Ekaterina S. Zalomaeva ◽  
...  
Keyword(s):  
Nervous System ◽  
Conditioned Reflex ◽  
Nervous Activity ◽  
Hypoxic Exposure ◽  
Experimental Conditions ◽  
Adaptive Capabilities ◽  
Mechanisms Of Adaptation ◽  
The Relationship ◽  
Conditioned Connection

M.E. Lobashev and V.В. Savvateev in 1959 obtained unique data on the expansion of the adaptive capabilities of the organism when training the properties of higher nervous activity by the formation of conditioned food reflexes to stimuli that exhaust the nervous system. Apparently, the formation of a conditioned connection help to overcoming stressful effects, adaptation to restrictive conditions, and changes in the functioning of the nervous system. To test this assumption, the influence of stressful influences hypoxia on learning and memory of Drosophila in the paradigm of conditioned reflex suppression of courtship was studied. The results were obtained on the enhancement of the ability to learn under hypoxic exposure. These experimental conditions did not affect memory formation. The effect of hypoxia on chromosomes through the formation of double-stranded breaks was revealed. The data are discussed in light of the relationship between neuroplasticity processes and mechanisms of adaptation to stressors.

scholarly journals Three-dimensional organization of Drosophila melanogaster interphase nuclei. II. Chromosome spatial organization and gene regulation.

1987 ◽  
Vol 104 (6) ◽  
pp. 1471-1483 ◽  
Author(s):  
M Hochstrasser ◽  
J W Sedat
Keyword(s):  
Gene Regulation ◽  
Drosophila Melanogaster ◽  
Nuclear Envelope ◽  
Spatial Organization ◽  
Polytene Chromosomes ◽  
Three Dimensional ◽  
Nucleolar Organizer ◽  
Cell Types ◽  
Functional Changes ◽  
Specific Subset

In the preceding article we compared the general organization of polytene chromosomes in four different Drosophila melanogaster cell types. Here we describe experiments aimed at testing for a potential role of three-dimensional chromosome folding and positioning in modulating gene expression and examining specific chromosome interactions with different nuclear structures. By charting the configurations of salivary gland chromosomes as the cells undergo functional changes, it is shown that loci are not repositioned within the nucleus when the pattern of transcription changes. Heterologous loci show no evidence of specific physical interactions with one another in any of the cell types. However, a specific subset of chromosomal loci is attached to the nuclear envelope, and this subset is extremely similar in at least two tissues. In contrast, no specific interactions between any locus and the nucleolus are found, but the base of the X chromosome, containing the nucleolar organizer, is closely linked to this organelle. These results are used to evaluate models of gene regulation that involve the specific intranuclear positioning of gene sequences. Finally, data are presented on an unusual class of nuclear envelope structures, filled with large, electron-dense particles, that are usually associated with chromosomes.

Longitudinal fMRI studies: Exploring brain plasticity and repair in MS

2015 ◽  
Vol 22 (3) ◽  
pp. 269-278 ◽  
Author(s):  
Christian Enzinger ◽  
Daniela Pinter ◽  
Maria A Rocca ◽  
John De Luca ◽  
Jaume Sastre-Garriga ◽  
...  
Keyword(s):  
Brain Plasticity ◽  
Future Research ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Cross Sectional ◽  
Functional Changes ◽  
Disease Modifying Therapies ◽  
Mechanisms Of Adaptation ◽  
Cross Sectional Studies ◽  
Cross Sectional Design

Functional magnetic resonance imaging (fMRI) has greatly advanced our understanding of cerebral functional changes occurring in patients with multiple sclerosis (MS). However, most of our knowledge regarding brain plasticity and repair in MS as evidenced by fMRI has been extrapolated from cross-sectional studies across different phenotypes of the disease. This topical review provides an overview of this research, but also highlights limitations of existing fMRI studies with cross-sectional design. We then review the few existing longitudinal fMRI studies and discuss the feasibility and constraints of serial fMRI in individuals with MS. We further emphasize the potential to track fMRI changes in evolving disease and the insights this may give in terms of mechanisms of adaptation and repair, focusing on serial fMRI to monitor response to disease-modifying therapies or rehabilitation interventions. Finally, we offer recommendations for designing future research studies to overcome previous methodological shortcomings.

scholarly journals Cytogenetic comparison of chironomid midge Glyptotendipes glaucus (Meigen, 1818) (Diptera, Chironomidae) populations from Northwest Russia and Ukraine (Chernobyl zone)

2012 ◽  
Vol 10 (2) ◽  
pp. 9-16 ◽  
Author(s):  
◽  
Sergey V Zhirov
Keyword(s):  
Salivary Glands ◽  
Chromosomal Rearrangements ◽  
Radioactive Pollution ◽  
Functional Changes ◽  
Balbiani Rings ◽  
Polythene Chromosomes ◽  
Glyptotendipes Glaucus ◽  
Chernobyl Zone

Functional characters of polythene chromosomes and chromosomal rearrangements in salivary glands of 177 larvae of Glyptotendipes glaucus (Diptera, Chironomidae) from reservoirs of Russia and Ukraine (Chernobyl) have been analysed. Similarity of the populations studied based on a pool of chromosomal reorganizations has been established. The general types of inversions in chromosomal arms A, B, D and E have been detected. Influence of radioactive pollution (Chernobyl) on functional changes of a nucleus, Balbiani rings, puffs, morphology of disks and interdisks is revealed. 

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