VARIATIONS IN GENETIC ARCHITECTURE AT DIFFERENT DOSES OF γ-RADIATION AS MEASURED BY LONGEVITY IN DROSOPHILA MELANOGASTER

1973 ◽  
Vol 15 (2) ◽  
pp. 289-298 ◽  
Author(s):  
Jane M. Westerman ◽  
P. A. Parsons

Longevity (as a measure of resistance to irradiation) has been examined after different doses of 60Co γ-rays, in four inbred lines and their hybrids in D. melanogaster. The control data showed some additive and non-additive effects. At 40, 60, 80, 100 and 120 krads, non-additive effects were highly significant, but additive effects were significant only at 100 and 120 krads, in particular the latter. Thus the genetic architecture varies with dose. Detailed genetic studies probably are simplest to carry out at high doses, because of the importance of additive effects.


2021 ◽  
pp. 51-56
Author(s):  
M.K. Ismayilova

The aim of this paper to study the effects of γ-rays on nanostructured Na-bentonite clay from Alpoid deposit. The effect of high doses (up to 256 kGy) of γ-radiation on the short-range structural organization in montmorillonite was studied using infrared spectroscopy. Significant change attributable to irradiation was observed at dose of 57 kGy. No significant changes were observed after 57 kGy of γ-radiation. A small variation in the water content was noted but it is not systematic. The results show that the montmorillonite structure can accumulate high doses of radiation with damage. The modifications most likely to be generated by the radiation were expected to be within the silicate layers. The morphology of the nanocomposites was studied with scanning electron microscopy. In this paper, the effects of ionizing radiation on the Na-bentonite clay investigated by FT-IR method. These spectra show the suitability of FT-IR study of mineral surfaces and the changes in the spectra brought about by the surface phenomena.



1995 ◽  
Vol 73 (02) ◽  
pp. 219-222 ◽  
Author(s):  
Manuel Monreal ◽  
Luis Monreal ◽  
Rafael Ruiz de Gopegui ◽  
Yvonne Espada ◽  
Ana Maria Angles ◽  
...  

SummaryThe APTT has been considered the most suitable candidate to monitor the anticoagulant activity of hirudin. However, its use is hampered by problems of standardization, which make the results heavily dependent on the responsiveness of the reagent used. Our aim was to investigate if this different responsiveness of different reagents when added in vitro is to be confirmed in an ex vivo study.Two different doses of r-hirudin (CGP 39393), 0.3 mg/kg and 1 mg/kg, were administered subcutaneously to 20 New Zealand male rabbits, and the differences in prolongation of APTT 2 and 12 h later were compared, using 8 widely used commercial reagents. All groups exhibited a significant prolongation of APTT 2 h after sc administration of hirudin, both at low and high doses. But this prolongation persisted 12 h later only when the PTTa reagent (Boehringer Mannheim) was used. In general, hirudin prolonged the APTT most with the silica- based reagents.In a further study, we compared the same APTT reagents in an in vitro study in which normal pooled plasma was mixed with increasing amount of hirudin. We failed to confirm a higher sensitivity for silica- containing reagents. Thus, we conclude that subcutaneous administration of hirudin prolongs the APTT most with the silica-based reagents, but this effect is exclusive for the ex vivo model.



2018 ◽  
Vol 1 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Darío Acuña-Castroviejo ◽  
Maria T Noguiera-Navarro ◽  
Russel J Reiter ◽  
Germaine Escames

Due to the broad distribution of extrapineal melatonin in multiple organs and tissues, we analyzed the presence and subcellular distribution of the indoleamine in the heart of rats. Groups of sham-operated and pinealectomized rats were sacrificed at different times along the day, and the melatonin content in myocardial cell membranes, cytosol, nuclei and mitochondria, were measured. Other groups of control animals were treated with different doses of melatonin to monitor its intracellular distribution. The results show that melatonin levels in the cell membrane, cytosol, nucleus, and mitochondria vary along the day, without showing a circadian rhythm. Pinealectomized animals trend to show higher values than sham-operated rats. Exogenous administration of melatonin yields its accumulation in a dose-dependent manner in all subcellular compartments analyzed, with maximal concentrations found in cell membranes at doses of 200 mg/kg bw melatonin. Interestingly, at dose of 40 mg/kg b.w, maximal concentration of melatonin was reached in the nucleus and mitochondrion. The results confirm previous data in other rat tissues including liver and brain, and support that melatonin is not uniformly distributed in the cell, whereas high doses of melatonin may be required for therapeutic purposes.



Author(s):  
Emmanuel Tiyo Ayikobua ◽  
Josephine Kasolo ◽  
Keneth Iceland Kasozi ◽  
Ejike Daniel Eze ◽  
Abass Safiriyu ◽  
...  

AbstractBackgroundThe Phosphatase and tensin-induced putative kinase 1 (PINK1B9) mutant for Drosophila melanogaster is a key tool that has been used in assessing the pathology of Parkinsonism and its possible remedy. This research was targeted toward determining the effects of ethanolic extract of propolis, with levodopa therapy in the management of Parkinsonism.MethodThe PINK1B9 flies were divided into groups and fed with the different treatment doses of ethanoic extract of propolis. The treatment groups were subjected to 21 days of administration of propolis and the levodopa at different doses after which percentage climbing index, antioxidant activity and lifespan studies were done.ResultsPropolis alone improved motor activity, antioxidant and lifespan in Drosophila melanogaster than in PINK1 flies. Propolis in combination with levodopa significantly (P<0.05) improved physiological parameters at higher than lower concentrations in Parkinsonism Drosophila melanogaster demonstrating its importance in managing side effects associated with levodopa.ConclusionPropolis is a novel candidate as an alternative and integrative medicinal option to use in the management of Parkinsonism in both animals and humans at higher concentrations.



2021 ◽  
Vol 14 (6) ◽  
pp. 593
Author(s):  
Sandra Fernández-Rodríguez ◽  
Claudia Esposito-Zapero ◽  
Teodoro Zornoza ◽  
Ana Polache ◽  
Luis Granero ◽  
...  

N-acetylcysteine (NAC) is a prodrug that is marketed as a mucolytic agent and used for the treatment of acetaminophen overdose. Over the last few decades, evidence has been gathered that suggests the potential use of NAC as a new pharmacotherapy for alcohol use disorder (AUD), although its mechanism of action is already being debated. In this paper, we set out to assess both the potential involvement of the glutamate metabotropic receptors (mGluR) in the possible dual effect of NAC administered at two different doses and NAC’s effect on ethanol-induced activation. To this aim, 30 or 120 mg/kg of NAC was intraperitoneally administered to rats with the presence or absence of the negative allosteric modulator of mGluR5 (MTEP 0.1 mg/kg). Thereafter, the cFOS IR-cell expression was analyzed. Secondly, we explored the effect of 120 mg/kg of NAC on the neurochemical and behavioral activation induced by intra-VTA ethanol administration (150 nmol). Our results showed that the high NAC dose stimulated cFOS expression in the NAcc, and that this effect was suppressed in the presence of MTEP, thus suggesting the implication of mGluR5. Additionally, high doses could attenuate the ethanol-induced increase in cFOS-expression in the NAcc, probably due to a phenomenon based on the long-term depression of the MSNs. Additional experiments are required to corroborate our hypothesis.





Author(s):  
Toshiyuki Sakai ◽  
Akira Abe ◽  
Motoki Shimizu ◽  
Ryohei Terauchi

Abstract Characterizing epistatic gene interactions is fundamental for understanding the genetic architecture of complex traits. However, due to the large number of potential gene combinations, detecting epistatic gene interactions is computationally demanding. A simple, easy-to-perform method for sensitive detection of epistasis is required. Due to their homozygous nature, use of recombinant inbred lines (RILs) excludes the dominance effect of alleles and interactions involving heterozygous genotypes, thereby allowing detection of epistasis in a simple and interpretable model. Here, we present an approach called RIL-StEp (recombinant inbred lines stepwise epistasis detection) to detect epistasis using single nucleotide polymorphisms in the genome. We applied the method to reveal epistasis affecting rice (Oryza sativa) seed hull color and leaf chlorophyll content and successfully identified pairs of genomic regions that presumably control these phenotypes. This method has the potential to improve our understanding of the genetic architecture of various traits of crops and other organisms.



Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 827
Author(s):  
Lisa J. Martin ◽  
D Woodrow Benson

Congenital heart defects (CHD) are malformations present at birth that occur during heart development. Increasing evidence supports a genetic origin of CHD, but in the process important challenges have been identified. This review begins with information about CHD and the importance of detailed phenotyping of study subjects. To facilitate appropriate genetic study design, we review DNA structure, genetic variation in the human genome and tools to identify the genetic variation of interest. Analytic approaches powered for both common and rare variants are assessed. While the ideal outcome of genetic studies is to identify variants that have a causal role, a more realistic goal for genetic analytics is to identify variants in specific genes that influence the occurrence of a phenotype and which provide keys to open biologic doors that inform how the genetic variants modulate heart development. It has never been truer that good genetic studies start with good planning. Continued progress in unraveling the genetic underpinnings of CHD will require multidisciplinary collaboration between geneticists, quantitative scientists, clinicians, and developmental biologists.



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