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1.
V. I. Korchagin A. A. Vergun S. A. Godakova O. N. Tokarskaya 《Russian Journal of Genetics》2013,49(3):367-370
The molecular structure of the allelic variants of (AAT) n of the Du47D microsatellite locus was determined in parthenogenetic lizards Darevskia dahli, D. armeniaca, and D. rostombekovi. Comparative analysis of these alleles showed that they were characterized by perfect structure of microsatellite cluster, and were different in the number of (AAT) monomeric units, as well as in the combinations of species-specific substitutions and deletions in the microsatellite flanking regions. Molecular structure of microsatellite cluster, species-specific single nucleotide polymorphism (SNP), and different representation of alleles Du47 in the samples of parthenogenetic species examined point to the origin of the alleles from different bisexual species, which is consistent with the hybrid nature of unisexual species of the genus Darevskia. In addition, these data reflect different combination patterns of interspecific hybridization events with the participation of the same bisexual species upon the formation of hybrid genomes of parthenogenetic species. Possible application of the allelic variants of microsatellite loci of parthenogenetic lizards as the genetic markers for the analysis of the genomes of parthenogenetic species in the light of evolution, ecology, and parthenogenetic type of reproduction in vertebrates is discussed. 相似文献
2.
Direct visualization of mitochondrial zinc accumulation reveals uniporter-dependent and -independent transport mechanisms 总被引:4,自引:0,他引:4
Current evidence suggests that zinc kills neurons by disrupting energy production, specifically by inhibiting mitochondrial function. However it is unclear if the inhibitory effect requires zinc accumulation, and if so, precisely how zinc enters mitochondria. Here, using fluorescence microscopy to visualize individual rat brain mitochondria, we detected matrix zinc uptake using the fluorophore FluoZin-3. Fluorescence increased rapidly in mitochondria treated with micromolar free zinc, and was quickly returned to baseline by membrane permeant chelation. Zinc uptake occurred through the calcium uniporter, because depolarization or uniporter blockade reduced fluorescence changes. However, increased fluorescence under these conditions suggests that zinc can enter through a uniporter-independent pathway. Fluorescence steadily declined over time and was unaffected by acidification or phosphate depletion, suggesting that zinc precipitation is not a mechanism for reducing matrix zinc. Uniporter blockade with ruthenium red also did not change the rate of zinc loss. Instead, zinc appears to exit the matrix through a novel efflux pathway not yet identified. Interestingly, dye-loaded mitochondria showed no fluorescence increase after treatment with strong oxidants, arguing against oxidant-labile intra-mitochondrial zinc pools. This study is the first to directly demonstrate zinc accumulation in individual mitochondria and provides insight about mechanisms mediating mitochondrial zinc uptake and efflux. 相似文献
3.
Jie Song Alok S. Desphande Timothy B. Meier Dana L. Tudorascu Svyatoslav Vergun Veena A. Nair Bharat B. Biswal Mary E. Meyerand Rasmus M. Birn Pierre Bellec Vivek Prabhakaran 《PloS one》2012,7(12)
Resting-state functional MRI (rs-fMRI) has emerged as a powerful tool for investigating brain functional connectivity (FC). Research in recent years has focused on assessing the reliability of FC across younger subjects within and between scan-sessions. Test-retest reliability in resting-state functional connectivity (RSFC) has not yet been examined in older adults. In this study, we investigated age-related differences in reliability and stability of RSFC across scans. In addition, we examined how global signal regression (GSR) affects RSFC reliability and stability. Three separate resting-state scans from 29 younger adults (18–35 yrs) and 26 older adults (55–85 yrs) were obtained from the International Consortium for Brain Mapping (ICBM) dataset made publically available as part of the 1000 Functional Connectomes project www.nitrc.org/projects/fcon_1000. 92 regions of interest (ROIs) with 5 cubic mm radius, derived from the default, cingulo-opercular, fronto-parietal and sensorimotor networks, were previously defined based on a recent study. Mean time series were extracted from each of the 92 ROIs from each scan and three matrices of z-transformed correlation coefficients were created for each subject, which were then used for evaluation of multi-scan reliability and stability. The young group showed higher reliability of RSFC than the old group with GSR (p-value = 0.028) and without GSR (p-value <0.001). Both groups showed a high degree of multi-scan stability of RSFC and no significant differences were found between groups. By comparing the test-retest reliability of RSFC with and without GSR across scans, we found significantly higher proportion of reliable connections in both groups without GSR, but decreased stability. Our results suggest that aging is associated with reduced reliability of RSFC which itself is highly stable within-subject across scans for both groups, and that GSR reduces the overall reliability but increases the stability in both age groups and could potentially alter group differences of RSFC. 相似文献
4.
Rajprasad Loganathan Mehmet Bilgen Baraa Al-Hafez Svyatoslav V Zhero Mohammed D Alenezy Irina V Smirnova 《Journal of applied physiology》2007,102(2):665-672
Diabetic cardiomyopathy is a distinct myocardial complication of the catabolic state of untreated insulin-dependent diabetes mellitus in the streptozotocin-induced diabetic rat. Exercise training has long been utilized as an effective adjunct to pharmacotherapy in the management of the diabetic heart. However, the in vivo functional benefit(s) of the training programs on cardiac cycle events in diabetes are poorly understood. In this study, we used three groups of Sprague-Dawley rats (sedentary control, sedentary diabetic, and exercised diabetic) to assess the effects of endurance training on the left ventricular (LV) cardiac cycle events in diabetes. At the end of 9 wk of exercise training, noninvasive cardiac functional evaluation was performed by using high-resolution magnetic resonance imaging (9.4 T). An ECG-gated cine imaging protocol was used to capture the LV cardiac cycle events through 10 equally incremented phases. The cardiac cycle phase volumetric profiles showed favorable functional changes in exercised diabetic group, including a prevention of decreased end-diastolic volume and attenuation of increased end-systolic volume that accompanies sedentary diabetes. The defects in LV systolic flow velocity, acceleration, and jerk associated with sedentary diabetes were restored toward control levels in the trained diabetic animals. This magnetic resonance imaging study confirms the prevailing evidence from earlier in vitro and in vivo invasive procedures that exercise training benefits cardiac function in this model of diabetic cardiomyopathy despite the extreme catabolic state of the animals. 相似文献
5.
Natalia E. Kichigina Jan V. Puhalsky Aleksander I. Shaposhnikov Tatiana S. Azarova Natalia M. Makarova Svyatoslav I. Loskutov Vera I. Safronova Igor A. Tikhonovich Margarita A. Vishnyakova Elena V. Semenova Irina A. Kosareva Andrey A. Belimov 《Physiology and Molecular Biology of Plants》2017,23(4):851-863
Our study aimed to evaluate intraspecific variability of pea (Pisum sativum L.) in Al tolerance and to reveal mechanisms underlying genotypic differences in this trait. At the first stage, 106 pea genotypes were screened for Al tolerance using root re-elongation assay based on staining with eriochrome cyanine R. The root re-elongation zone varied from 0.5 mm to 14 mm and relationships between Al tolerance and provenance or phenotypic traits of genotypes were found. Tolerance index (TI), calculated as a biomass ratio of Al-treated and non-treated contrasting genotypes grown in hydroponics for 10 days, varied from 30% to 92% for roots and from 38% to 90% for shoots. TI did not correlate with root or shoot Al content, but correlated positively with increasing pH and negatively with residual Al concentration in nutrient solution in the end of experiments. Root exudation of organic acid anions (mostly acetate, citrate, lactate, pyroglutamate, pyruvate and succinate) significantly increased in several Al-treated genotypes, but did not correlate with TI. Al-treatment decreased Ca, Co, Cu, K, Mg, Mn, Mo, Ni, S and Zn contents in roots and/or shoots, whereas contents of several elements (P, B, Fe and Mo in roots and B and Fe in shoots) increased, suggesting that Al toxicity induced substantial disturbances in uptake and translocation of nutrients. Nutritional disturbances were more pronounced in Al sensitive genotypes. In conclusion, pea has a high intraspecific variability in Al tolerance and this trait is associated with provenance and phenotypic properties of plants. Transformation of Al to unavailable (insoluble) forms in the root zone and the ability to maintain nutrient uptake are considered to be important mechanisms of Al tolerance in this plant species. 相似文献
6.
Ekaterina?D.?BadaevaEmail author Alevtina?S.?Ruban Svyatoslav?A.?Zoshchuk Sergei?A.?Surzhikov Helmut?Knüpffer Benjamin?Kilian 《Plant Systematics and Evolution》2016,302(8):943-956
Triticum timopheevii (2n = 4x = 28, GGAtAt) is a tetraploid wheat formerly cultivated in western Georgia. The natural allopolyploid Triticum zhukovskyi is a hexaploid taxon originated from hybridization of T. timopheevii with cultivated einkorn T. monococcum (2n = 2x = 14, AmAm). Karyotypically T. timopheevii and T. zhukovskyi differ from other tetraploid and hexaploid wheats and were assigned to the section Timopheevii of the genus Triticum L. Triticum timopheevii and T. zhukovskyi are resistant to many fungal diseases and therefore could potentially be utilized for wheat improvement. We were aiming to precisely identify all T. timopheevii chromosomes and to trace the evolution of T. zhukovskyi. For this, we developed a set of molecular cytogenetic landmarks based on eleven DNA probes. Each chromosome can now be characterized by two to eight probes. The pTa-535 sequence allows the identification of all At-genome chromosomes, whereas G-genome and some At-genome chromosomes can be identified using (GAA/CTT) n and pSc119.2 probes. The probes pAesp_SAT86, pAs1, Spelt-1, Spelt-52 and 5S and 45S rDNA can be applied as additional markers to discriminate particular chromosomes or chromosomal regions. The distribution of (GAA/CTT) n , pTa-535 and pSc119.2 DNA probes on T. timopheevii chromosomes is distinct from other tetraploid wheats and can therefore be used to track individual chromosomes in introgression programs. Our study confirms the origin of T. zhukovskyi from hybridization of T. timopheevii with T. monococcum; however, we show that the emergence was accompanied by changes involving mostly At-genome chromosomes. This may be due to the presence of two closely related A-genomes in the T. zhukovskyi karyotype. 相似文献
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8.
Volokhina I Gusev Y Mazilov S Chumakov M 《Journal of bioinformatics and computational biology》2012,10(2):1241009
The transfer of single-stranded (ss) T-DNA from soil bacteria of the genus Agrobacterium with the help of the VirE2 protein, which possibly mediates the delivery of ss-T-DNA across the cell membrane, was demonstrated earlier, but how VirE2 participates in ssDNA transfer across artificial and natural membranes is not known. Using computational methods, we reconstructed model structures composed of two and four VirE2 proteins and showed by the MOLE program the formation of pores with channel diameters of 1.2-1.6 and 1.4-4.6 nm in a model structure formed from two and four VirE2 molecules, respectively. Using light scattering, we recorded the size distribution for recombinant VirE2-dependent complexes in aqueous solutions and found that VirE2 in a buffer solution is present as a complex made up of two or more proteins. We revealed single, long-lived jumps in voltage-dependent membrane conductance during coincubation of planar black membranes with the VirE2 protein. On the addition of VirE2 and FAM-labeled oligonucleotides to HeLa cells, the fluorescence intensity for the cells increased by 56% as compared to that for cells incubated only with oligonucleotides. 相似文献
9.
Osipov F. A. Vergun A. A. Arakelyan M. S. Petrosyan R. K. Dergunova N. N. Neymark L. A. Petrosyan V. G. 《Biology Bulletin》2021,48(6):681-692
Biology Bulletin - The results of the analysis of the genetic variability of parthenogenetic Darevskia rostombekowi (Darevsky, 1957) species using four microsatellite-containing loci are presented.... 相似文献
10.
Olga Vergun 《BBA》2005,1709(2):127-137
Ca2+-induced mitochondrial depolarization was studied in single isolated rat brain and liver mitochondria. Digital imaging techniques and rhodamine 123 were used for mitochondrial membrane potential measurements. Low Ca2+ concentrations (about 30-100 nM) initiated oscillations of the membrane potential followed by complete depolarization in brain mitochondria. In contrast, liver mitochondria were less sensitive to Ca2+; 20 μM Ca2+ was required to depolarize liver mitochondria. Ca2+ did not initiate oscillatory depolarizations in liver mitochondria, where each individual mitochondrion depolarized abruptly and irreversibly. Adenine nucleotides dramatically reduced the oscillatory depolarization in brain mitochondria and delayed the onset of the depolarization in liver mitochondria. In both type of mitochondria, the stabilizing effect of adenine nucleotides completely abolished by an inhibition of adenine nucleotide translocator function with carboxyatractyloside, but was not sensitive to bongkrekic acid. Inhibitors of mitochondrial permeability transition cyclosporine A and bongkrekic acid also delayed Ca2+-depolarization. We hypothesize that the oscillatory depolarization in brain mitochondria is associated with the transient conformational change of the adenine nucleotide translocator from a specific transporter to a non-specific pore, whereas the non-oscillatory depolarization in liver mitochondria is caused by the irreversible opening of the pore. 相似文献