Publications by authors named "Shekhovtsov S"

The Pallas' spadefoot Pelobates vespertinus is a frog species native to eastern Europe and west Siberia. This species resists harsh winter conditions by moving up to 2 m underground. This amphibian is the first species known to withstand extreme air hypoxia.

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Earthworms are known for their intricate systematics and a diverse range of reproduction modes, including outcrossing, self-fertilization, parthenogenesis, and some other modes, which can occasionally coexist in a single species. Moreover, they exhibit considerable intraspecific karyotype diversity, with ploidy levels varying from di- to decaploid, as well as high genetic variation. In some cases, a single species may exhibit significant morphological variation, contain several races of different ploidy, and harbor multiple genetic lineages that display significant divergence in both nuclear and mitochondrial DNA.

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The Siberian frog Rana amurensis has a uniquely high tolerance to hypoxia among amphibians, as it is able to withstand several months underwater with almost no oxygen (0.2 mg/liter) vs. several days for other studied species.

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Anoxia is a significant challenge for most animals, as it can lead to tissue damage and death. Among amphibians, the Siberian frog is the only known species capable of surviving near-zero levels of oxygen in water for a prolonged period. In this study, we aimed to compare metabolomic profiles of the liver, brain, and heart of the Siberian frog exposed to long-term oxygen deprivation (approximately 0.

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Several earthworm species are known to be able to withstand freezing. At the biochemical level, this ability is based on cryoprotectant accumulation as well as several other mechanisms. In this study, we used H NMR to investigate metabolomic changes in two freeze-tolerant earthworm taxa, Dendrobaena octaedra and one of the genetic lineages of Eisenia sp.

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Earthworms are an important ecological group that has a significant impact on soil fauna as well as plant communities. Despite their importance, genetic diversity and phylogeny of earthworms are still insufficiently studied. Most studies on earthworm genetic diversity are currently based on a few mitochondrial and nuclear genes.

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A survey of the earthworm fauna of Belarus that included most of its territory was performed in this study. One genus, three species and one subspecies were reported for the first time. The fauna of Belarus thus comprises 17 species and two subspecies.

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It is known that fullerenes are poorly soluble in polar solvents, but readily form colloidal solutions in such media. These solutions are typically solvophobic (hydrophobic when prepared in water), that is, thermodynamically unstable colloidal systems with negatively charged particles. To understand the stability factors of a colloidal system, the thresholds for coagulation of a sol or suspension by electrolytes are of key importance.

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The moor frog is one of a few amphibians that can tolerate freezing to low temperatures, up to -16 °C. In this study, we performed metabolomic analysis of the liver and hindlimb muscles of frozen and control . We found that the moor frog synthesizes glucose and glycerol in similar concentrations as low molecular weight cryoprotectants.

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The Siberian wood frog Rana amurensis Boulenger, 1886 is the most hypoxia-tolerant amphibian. It can survive for several months in an almost complete absence of oxygen. Little is known about the mechanisms of this remarkable resilience, in part because studies of amphibian genomes are impeded by their large size.

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In this review, we discuss the progress in the study and modification of subtilisin proteases. Despite longstanding applications of microbial proteases and a large number of research papers, the search for new protease genes, the construction of producer strains, and the development of methods for their practical application are still relevant and important, judging by the number of citations of the research articles on proteases and their microbial producers. This enzyme class represents the largest share of the industrial production of proteins worldwide.

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The Siberian salamander Dybowski, 1870 is a unique amphibian that is capable to survive long-term freezing at -55 °C. Nothing is known on the biochemical basis of this remarkable freezing tolerance, except for the fact that it uses glycerol as a low molecular weight cryoprotectant. We used H-NMR analysis to study quantitative changes of multiple metabolites in liver and hindlimb muscle of in response to freezing.

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The size of the nuclear genome in eukaryotes is mostly determined by mobile elements and noncoding sequences and may vary within wide limits. It can differ signif icantly both among higher-order taxa and closely related species within a genus; genome size is known to be uncorrelated with organism complexity (the so-called C-paradox). Less is known about intraspecif ic variation of this parameter.

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Article Synopsis
  • The Kuril Archipelago, part of the Circum-Pacific Belt, has unique thermal springs, yet limited studies on their microbial communities have been done using modern molecular methods.
  • This research is the first metagenomic study of thermophilic microbial communities in Kunashir Island, focusing on two sites: Faust Lake and Tretyakovsky Thermal Spring.
  • Faust Lake has a dominant red algae species and a diverse archaeal population, while Tretyakovsky shows higher overall microbial diversity but no shared species between the two springs, highlighting distinct microbial communities even within close geographical proximity.*
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For accurate species-level identification of microorganisms, researchers today increasingly use a combination of standard microbiological cultivation and visual observation methods with molecular biological and genetic techniques that help distinguish between species and strains of microorganisms at the level of DNA or RNA molecules. The aim of this work was to identify microorganisms from the ICG SB RAS Collection using an integrated approach that involves a combination of various phenotypic and genotypic characteristics. Key molecular-genetic and phenotypic characteristics were determined for 93 microbial strains from the ICG SB RAS Collection.

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Vavilovskii Zhurnal Genetiki i Selektsii = Vavilov Journal of Genetics and Breeding. 2019;23(8):1076-1081 (in Russian) Page 1081, in Acknowledgements instead of This work was supported by State Budgeted Project АААА-А17-117092070032-4. should read This work was supported by State Budgeted Project 0259-2019-0011.

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Dendrobaena schmidti (Michaelsen, 1907) is a polymorphic earthworm species from the Caucasus and adjacent regions. Adult D. schmidti individuals have highly variable body size (from 1.

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Article Synopsis
  • - The study focuses on an autochthonous Siberian earthworm species known for its wide distribution across various ecosystems and high levels of diversity, prompting the idea of splitting it into multiple species.
  • - Researchers used genetic analysis, including COI gene diversity and transcriptome sequencing, to investigate the species' phylogeny, finding it to be monophyletic but divided into two distinct clades based on geographical distribution.
  • - The authors propose to classify the species into two separate species based on these findings, abolishing the current recognition of a non-pigmented subspecies and expanding another to include previously identified lineages.
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Article Synopsis
  • * Researchers studied the microbial communities in the oil site, identifying their genetic characteristics and metabolic pathways related to hydrocarbon degradation, revealing significant links between geochemical factors and microbial community structure.
  • * The study concluded that geochemical parameters shape the composition and metabolic capabilities of these communities, with a predominant metabolic pathway for hydrocarbon oxidation, supporting the theory of abiogenic synthesis of Uzon’s hydrothermal petroleum.
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The Siberian wood frog Rana amurensis is a recently discovered example of extreme hypoxia tolerance that is able to survive several months without oxygen. We studied metabolomic profiles of heart and liver of R. amurensis exposed to 17 days of extreme hypoxia.

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In this article, we examined the fluorescent properties of 4'- and 5'-aminofluorescein, unsubstituted fluorescein, and its 4'-nitro derivative in a set of solvent systems. Fluorescence lifetimes, quantum yields, time-resolved fluorescence spectra, and quantum chemical calculations allowed clarifying the reasons of the emitting properties in this dye series. In water, the dianions R of aminofluoresceins are practically nonfluorescent; in alcohols, the quantum yields are low.

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Within the course of this spectroscopic research, we revealed novel features of the protolytic behavior, which extend the knowledge of the chemistry of xanthene dyes and rationalize the utilization of these compounds. In addition to the well-known tautomerism of the molecular form, HR, of fluorescein dyes, new aspects of tautomeric transformation of anions are disclosed. First, for the dyes bearing the substituents in the phthalic acid residue, 4'- and 5'-aminofluoresceins and 4'-fluorescein isothiocyanate, the monoanion HR exists in non-hydrogen-bond donor solvents not only as a tautomer with the ionized carboxylic and nonionized OH group but also as a "phenolate" ion with a nonionized COOH group.

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Rice growing requires highly destructive and highly invasive field management negatively affecting soil biota and its functions. We aimed to compare taxonomic and functional trait compositions of soil macrofauna at different stages of rice cropping cycles in the three temperate rice-growing regions in Russia. Samples were collected in 2016 at four different biotopes in each region: flooded rice paddies; upland crops planted one year after flooded rice; rice paddy bunds; and relatively undisturbed seminatural control grasslands.

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Article Synopsis
  • * Researchers performed RNA sequencing on five specimens from different genetic lineages and discovered that most genes were highly conserved, but distinct differences did exist among the lineages, particularly when compared to closely related species.
  • * The findings suggest that these genetic lineages are distinct at the nuclear level and may represent separate species within the E. nordenskioldi complex, indicating a complex evolutionary history without clear geographic patterns.
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A rare observation of systemic AL-amyloidosis with a debut in old age, accompanied by diffuse alveolar-septal lesion of the lungs and mediastinal lymphadenopathy in combination with amyloid cardiomyopathy in the absence of pathology of kidney and liver function.

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