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Fishes of the genus Eleginus (Gadidae) are typical representatives of the ichthyofauna of the Northern Hemisphere; they play an important trophic role in the marine ecosystems of the Arctic and North Pacific and serve as targets of commercial and artisanal coastal fishing in many areas of the Russian North and Far East, as well as in areas of the coast of Alaska and northern Japan. The level of knowledge about the intraspecific organization of representatives of the genus Eleginus that is necessary for the rational exploitation of their stocks remains insufficient and their interspecific relationships have so far been analyzed using limited materials. This paper presents the first study of the interspecific relationships and intraspecific structure of navaga ( E. nawaga ) and saffron cod ( E. gracilis ) using a large-scale material (986 specimens in 29 samples from most of the species ranges) based on analysis of the polymorphism of mtDNA gene Cyt b . It is shown that they are independent, genetically differentiated species and their comparison with representatives of the genus Microgadus indicates that both species of the genus Eleginus might originate from a common ancestor close to M. proximus , while the divergence in the genus Microgadus occurred much earlier. Data on the haplotypic composition of saffron cod samples inhabiting areas from the Peter the Great Bay to Alaska waters and navaga samples inhabiting areas from the White Sea to the Ob Bay of the Kara Sea are given, which makes it possible to consider the phylogeographic history of both species and their intraspecific organization within the studied areas. Three groups can be distinguished for saffron cod: (1) Pacific–Japanese–Sakhalin group, (2) Chukchi–Bering seas group, and (3) intermediate group, which includes samples from the Sea of Okhotsk and waters of the northern Kurils.

Polymorphism in the variable fragment of the mtDNA control region (D-loop, 373 bp) and four microsatellite loci in 683 specimens of the Pacific herring Clupea pallasii sampled at different locations from the Asian part of range has been studied. It is shown that the Pacific herring lake forms inhabiting the three lakes on Sakhalin Island (Ainskoe) and in the Kamchatka Peninsula (Vilyuy and Nerpiche) have significantly diverged from the marine forms according to the data on the mtDNA and nDNA markers. The genetic variations among the herring forms inhabiting different lakes ( F ST = 0.034−0.066) and between the lake herring forms and marine herring forms ( F ST = 0.004−0.055) are revealed. The level of the genetic differentiation among the lake herring forms is much higher than that among the samples of the marine herring forms, which may be explained by the founder effect. Evolution of the lake forms occurred along with the geological processes producing the lakes.

Samples of Greenland halibut Reinhardtius hippoglossoides (Jordan and Snyder, 1901) from the Atlantic, Arctic, and Pacific Oceans were compared using eight microsatellite loci and the Cyt b mtDNA gene. The data obtained revealed a population connectivity of the Greenland halibut from the Laptev Sea to those from the Atlantic Ocean that is result of considerable eastward range extension due to recent climate change. Genetic differences between the Greenland halibut groupings of the Atlantic and Pacific Oceans, according to F st values (0.141–0.197), reach a high level. Given the genetic differences revealed by both nuclear and mitochondrial markers, the taxonomic status of the Greenland halibut inhabiting the Pacific Ocean requires reevaluation at least to the rank of subspecies. It is suggested that the Greenland halibut populations of the Atlantic Ocean basin originated from those of the North Pacific. The time and conditions of Greenland halibut penetration from the North Pacific to the Atlantic Ocean are discussed.

The phylogeographic analysis of Gadus chalcogrammus from the Asian part of the range (the western part of the Bering Sea, the Sea of Okhotsk and the Sea of Japan, the Pacific waters of the Kuril Islands and Kamchatka) based on data on the polymorphism of the mtDNA control region fragment ( D-loop , 526 bp) was performed for the first time using large-scale material (1162 individuals from 38 samples). The obtained results indicate the existence of two large groups in the surveyed water area: one is localized in the western part of the Bering Sea, and the other is formed by samples from the Sea of Japan and the Sea of Okhotsk and from the Pacific waters of the Kuril Islands and Kamchatka. An unusually low level of polymorphism in the mtDNA control region of Gadus chalcogrammus was revealed, which was also previously found in G. macrocephalus and is probably due to similar microevolutionary processes that took place in the past in both species.

Ribonucleoside hydrolase C (RihC, EC 3.2.2.1, 3.2.2.2, 3.2.2.3, 3.2.2.7, 3.2.2.8) belongs to the family of ribonucleoside hydrolases Rih and catalyzes the cleavage of ribonucleosides to nitrogenous bases and ribose. RihC is one of the enzymes that are synthesized by lactobacilli in response to the presence of Klebsiella. To characterize this protein from Limosilactobacillus reuteri LR1, we cloned and expressed it. The activity of the enzyme was studied towards a wide range of substrates, including ribonucleosides, deoxyribonucleosides as well as an arabinoside. It was shown that the enzyme is active only with ribonucleosides and arabinoside, with the best substrate being uridine. The thermal stability of this enzyme was studied, and its crystal structure was obtained, which demonstrated the tetrameric architecture of the enzyme and allowed to shed light on a correlation between its structure and enzymatic activity. Comprehensive comparisons of all known RihC structures, both existing crystal structures and computed model structures from various species, were made, allowing for the identification of structural motifs important for enzyme functioning.

AbstractNew stationary phases for hydrophilic chromatography (HILIC) with functional layers formed by the multicomponent Ugi reaction have been obtained. Acetone, glycolic acid, ethyl isocyanacetate, and 3‑aminopropyl silica, which also act as adsorbent matrices, were used as reaction components. The study of the effect of solvent on the reaction yield showed that a high degree of coverage of the matrix was achieved when the reaction was carried out in ethanol. The new adsorbents’ chromatographic properties compared with the initial matrix were assessed using the Tanaka tests for hydrophilic phases and by studying the retention of polar analytes from various classes. The synthesized adsorbents have demonstrated high efficiency and selectivity in separating model mixtures of sugars, amino acids, and water-soluble vitamins in the HILIC mode.

Adsorbents based on various substrates—silica and a copolymer of styrene with divinylbenzene—are developed for the determination of amino acids by hydrophilic interaction liquid chromatography—mass spectrometry. The optimal version of the structure of the functional layer in two series of the obtained stationary phases was chosen, which provides the best hydrophilization for each substrate. Retention mechanisms were studied and the conditions for the mass-spectrometric detection, separation, and determination of 16 amino acids were chosen. The applicability of the obtained adsorbents and a method for determining amino acids for the analysis of soil extracts were estimated.

Habitat loss threatens large mammals worldwide, and their survival will depend on habitat in human-dominated landscapes. Conservation planners thus face the challenge to identify areas of least conflict with land use, yet broadscale species distribution models rarely incorporate real landscape patterns nor do they identify potential conservation conflicts. An excellent example of such conservation challenges is provided by European bison ( Bison bonasus ). Almost extinct by the early 20th century, bison can only survive in the wild if large metapopulations are established, but it is unclear where new herds can be reintroduced. Using European bison as an example we conducted a continental-scale habitat assessment based on real landscape patterns. Our specific aims here were to (1) map European bison habitat throughout the species' former range, (2) examine whether broadscale habitat suitability factors differ from previously reported fine-scale factors, and (3) assess where suitable habitat occurs in areas with low potential for conflict with land use. We assessed habitat suitability using herd range maps for all 36 free-ranging European bison herds as habitat use data. Habitat suitability maps were compared with maps of land cover, livestock density, agricultural constraints, and protected areas to assess potential conservation conflicts. Our models had high goodness of fit (AUC == 0.941), and we found abundant potential bison habitat. European bison prefer mosaic-type landscapes, with a preference for broad-leaved and mixed forests. European bison metapopulations do not appear to be limited by habitat availability. However, most potential habitat occurred outside protected areas and has substantial potential for conservation conflicts. The most promising areas for establishing large bison metapopulations all occur in Eastern Europe (i.e., the Carpathians, the Belarus-–Ukraine borderlands, and several regions in European Russia). The future of European bison and that of other large mammals in the wild thus clearly lies in Eastern Europe, because habitat there is most abundant and least fragmented, and because the potential for conflict with land use is lower. More generally we suggest that broadscale habitat assessments that incorporate land use can be powerful tools for conservation planning and will be key if large herbivore and carnivore conservation is to succeed in a human-dominated world.

Ribonucleoside hydrolase C (RihC, EC 3.2.2.1, 3.2.2.2, 3.2.2.3, 3.2.2.7, 3.2.2.8) belongs to the family of ribonucleoside hydrolases Rih and catalyzes the cleavage of ribonucleosides to nitrogenous bases and ribose. RihC is one of the enzymes that are synthesized by lactobacilli in response to the presence of Klebsiella. To characterize this protein from Limosilactobacillus reuteri LR1, we cloned and expressed it. The activity of the enzyme was studied towards a wide range of substrates, including ribonucleosides, deoxyribonucleosides as well as an arabinoside. It was shown that the enzyme is active only with ribonucleosides and arabinoside, with the best substrate being uridine. The thermal stability of this enzyme was studied, and its crystal structure was obtained, which demonstrated the tetrameric architecture of the enzyme and allowed to shed light on a correlation between its structure and enzymatic activity. Comprehensive comparisons of all known RihC structures, both existing crystal structures and computed model structures from various species, were made, allowing for the identification of structural motifs important for enzyme functioning.

This study presents a comprehensive analysis of cysteine synthase A (CysK) from Limosilactobacillus reuteri LR1 (LreCysK), an enzyme involved in the biosynthesis of L-cysteine. This protein supports crucial cellular functions such as sulfur metabolism, antioxidant defense, detoxification, and protein synthesis. Previously, the gene encoding LreCysK was cloned, and the enzyme with His-tag on the N-terminus was obtained in active and soluble form. Here, kinetic parameters of the enzyme were determined by the previously developed high-pressure liquid chromatography (HPLC) and ninhydrin methods. It was found that LreCysK has similar KMOAS and kcat as CysKs from Escherichia coli and from the model plant Arabidopsis thaliana. The thermal stability of LreCysK was studied using differential scanning calorimetry. It was revealed that the melting point of the enzyme increases to almost 90°C when Pyridoxal-5 phosphate (PLP) is added, indicating that the stability of the enzyme complex with PLP is relatively high. Structural studies revealed that LreCysK is a dimer, and its active site is similar to those of other enzymes, but exhibits some features characteristic of lactobacilli CysKs (GISA), as well as unique residues, such as Ile50. Also, the potential biotechnological applications of LreCysK are discussed. These findings enhance our understanding of LreCysK’s biochemical versatility and its potential applications in biotechnology and medicine.