Increase of mutation level in tissues of goby and fry of sturgeon under conditions of block by antibodies against serotonin-modulated anticonsolidation protein

The work present data on studies of a decreased activity of serotoninergic system on the level of mutagenic changes (the micronuclear test) in the goby Neogobius fluviatilis and the fry if sturgeon Acipenser güldenst?dti persicus. It has been shown that the long exposure of the animals to conditions of industrial and oil pollution leads to a significant decrease in their liver of the level of serotonin-modulated anticonsolidation protein (SMAP) correlating directly with the serotonin level as well as to sharp increase of the level of micronuclei in erythrocytes. The intramuscular administration of anti-SMAP polyclonal antibodies to the fry of the sturgeon produces a significant increase of the amount of micronuclei as compared with that in the animals injected with non-immune gamma-globulin. The obtained results allow concluding that the decrease of activity of the serotoninergic system is the mechanism that is triggered with adverse environmental factors and realizes mutagenic damages in the modified genetic apparatus.     

Participation of serotoninmodulated anticonsolidation protein in mediation of action of adverse factors on lipid peroxidation level in tissues of sturgeon fry <Emphasis Type="Italic">Acipenser güldenstädti persicus</Emphasis>

The work analyzes participation of the serotoninergic system in correction of adverse effects of benthic deposits contaminated with industrial wastes on the level of lipid peroxidation (LPO) in the fry of the sturgeon Acipenser güldenstädti persicus. In the first series of the study, two intramuscular injections to the sturgeon fry of serotonin-modulated anticonsolidation protein (SMAP) that is in the direct correlation with the serotonin level led to pronounced normalization in the animal tissues of the LPO level whose increase was due to keeping the sturgeons in the fresh water contaminated with benthic deposits. In the second series of the study, administration to the animals of polyclonal anti-SMAP antibodies led to a significant increase of the LPO level in the tissues, similar to effects of the benthic deposits. It is concluded that adverse factors can produce their negative pro-oxidative effects on the organism tissues through a decrease of activity of the serotoninergic system, whereas an artificial increase of the serotoninergic system activity promotes correction of the oxidative stress.     

Antimutagenic activity of serotoninergic system and underlying mechanisms in fry of sturgeon and goldfish

The paper deals with antimutagenic body activity and its underlying mechanisms. The experiments carried out on the one-year old sturgeons (Acipenser gueldenstaedti persicus) and goldfish (Carassius auratus) have shown that intramuscular administration of serotonin-modulated anticonsolidation protein (SMAP) leads to a twofold decrease of erythrocyte mutagenic alterations (the micronuclear test, p < 0.01) caused by action of benthic deposits (0.8 ml/l, 3 days) polluted with industrial wastes. Exposure of goldfish in water contaminated with crude oil (500 mg/l, 3 days) led to a sharp rise of the content of the 70 kDa brain protein fraction (p < 0.001); these water-soluble proteins are assumed to belong to heat shock proteins (HSP). At the same time, in the brain of the studied animals there was observed a simultaneous increase of the SMAP content (p < 0.001). After 3 h, intracerebral SMAP administration to goldfish increased significantly the 90 kDa protein fraction content (p < 0.01), probably HSP90, in the electrophoretic profiles of the brain water-soluble proteins. Thus, the obtained results indicate that the body serotoninergic system has the antimutagenic activity providing protection of cells from action of harmful environmental factors by an enhancement of synthesis of proteins suggested to belong to HSP.     

Proliferative zones in the brain of the Amur sturgeon fry. Interactions with neuromeres and migration of secondary matrix zones

Neurogenesis in the forebrain region was studied in the Amur sturgeon Acipenser schrenki fry using immunocytochemical marking of the proliferative nuclear antigen. The brain zones with high proliferative activities were located at the brain ventricle surface facing the periventricular cavity. In addition to the periventricular zone of primary proliferation, several secondary proliferative zones were found in the forebrain region of the Amur sturgeon Acipenser schrenki.     

Polymorphism of the mitochondrial DNA control region in eight sturgeon species and development of a system for DNA-based species identification

Intraspecific and interspecific nucleotide sequence variations of the mtDNA control region (D-loop) were studied with mtDNAs isolated from tissue specimens of more than 1400 sturgeons of nine species: Russian sturgeon Acipenser gueldenstaedtii, Persian sturgeon A. persicus, Siberian sturgeon A. baerii, Amur sturgeon A. schrenkii, Fringebarbel sturgeon A. nudiventris, sterlet A. ruthenus, stellate sturgeon A. stellatus, beluga Huso huso, and kaluga H. dauricus. The results were used to analyze the interspecific variation of the mtDNA control region in the given set of species and to develop a test system of ten species-specific primers, which allowed species identification from noninvasive tissue samples, spawn, and food products of eight species. The system proved suitable for multiplex PCR. A method was developed for the first time to reliably differentiate the A. baerii mitotype and the baerii-like mitotype of A. gueldenstaedtii. It was found that, although genetically separate, A. gueldenstaedtii and A. persicus are relatively young species and have common mitochondrial haplotypes, precluding their identification via mtDNA analysis alone. To develop a system for species identification of A. gueldenstaedtii and A. persicus, it is necessary to study the polymorphism of nuclear markers.     

The low level of differences between mitogenomes of the Sakhalin sturgeon <Emphasis Type="Italic">Acipenser mikadoi</Emphasis> Hilgendorf, 1892 and the green sturgeon <Emphasis Type="Italic">A. medirostris</Emphasis> Ayeres, 1854 (Acipenseridae) indicates their recent divergence

The complete mitochondrial genome of the Sakhalin sturgeon Acipenser mikadoi and two mitogenomes of the Amur sturgeon A. schrenckii were sequenced using Roche 454 technology. The mitogenomes of the green sturgeon A. medirostris (obtained from GenBank) and the Sakhalin sturgeon differ as much as the mitogenomes of two mtDNA haplogroups (SM and BG) found in the same population of the Amur sturgeon: 0.0042 ± 0.0006 and 0.0036 ± 0.0005 substitutions per site (Tamura–Nei distance, TrN), respectively. The differences of these mitogenome pairs from mitogenomes of sister species (kaluga A. dauricus and white sturgeon A. transmontanus) are 3–6 times larger: 0.0260 ± 0.0015 and 0.0102 ± 0.0008, respectively. Thus, the differences between the mitogenomes of the Sakhalin and green sturgeons can be attributed to the variability at the intraspecific level. The time that has passed since the divergence of the Sakhalin and green sturgeons is considered to be much shorter than was previously believed: approximately 0.16 rather than 9.60 million years.     

The revision of the validity of genus <Emphasis Type="Italic">Huso</Emphasis> (Acipenseridae) based on recent morphological and genetic data with particular reference to the Kaluga <Emphasis Type="Italic">H. dauricus</Emphasis>

The comparative morphological study in different Acipenseriform species demonstrates that there are only two morphological features combining the kaluga and the great sturgeon and separating them from other sturgeons, namely the shape of a mouth and the manner attaching of gill membranes to isthmus in adult specimens; whereas many morphological characters are different in these species. The relations of morphological similarity/distinction among different sturgeon species and polyphyletic origin of genus Huso revealed by both molecular and cytogenetic studies presume the restoration of initial taxonomic states for the great sturgeon and kaluga as members of the same genus Acipenser, namely A. huso and A. dauricus.     

Organization of diencephalon of the sturgeons. External nuclei of the pretectal area

Cytoarchitectonics of the external nuclei of the pretectal area was studied in four species of the sturgeons: great sturgeon, Huso huso L., Kura sturgeon, Acipenser gueldenstaedtii persicus n. Kurensis Belyaeff, stellate sturgeon, Ac. stellatus Pall. and barbel sturgeon, Ac. nudiventris Lov. Study of morphological organization of the structures was carried out using routine Nissl staining and Bilschowski impregnation technique in Viktorov’s modification. Similar structure of this pretectal area was found in the species. Five nuclear formations were described in this pretectal area: parvocellular and magnocellular external pretectal nuclei, laminiform nucleus of pretectum, dorsal pretectal nucleus, and the accessory optic nucleus. Comparison of the obtained data with the literature revealed a high level of differentiation of the area of pretectum in the sturgeons. Also, a general conclusion is given on the organization of the whole pretectal area in the sturgeons.     

Selective predation by reintroduced juvenile Lake sturgeon (<Emphasis Type="Italic">Acipenser fulvescens</Emphasis>) in Ft. Loudoun reservoir,Tennessee (USA)

Following water quality and minimum flow improvements to the impounded Tennessee and Cumberland Rivers, juvenile lake sturgeon (Acipenser fulvescens) have been restocked annually since 2000. Our goal was to seasonally assess foraging mode of this recovering population in Ft. Loudoun Reservoir in the Upper Tennessee River. During 2014–15, individuals were captured using trot-lines in a 13-km reach that supports the greatest density of lake sturgeon. We used colonic flushing and gastric lavage techniques to obtain diet. We took systematic benthic sediment grabs along multiple transects throughout the reach and opportunistically deployed rock cages filled with hard substrates to assess potential prey that colonize hard surfaces. Foraging modes of lake sturgeon were determined by comparing relative abundances of invertebrate taxa in the gut contents (6581 invertebrates) of 28 fish to the relative abundances of the same invertebrate taxa collected from the resource base (1667 invertebrates). Proportional similarity, Levin’s niche breadth, and Manly’s index were used to assess the degree of prey selectivity. Lake sturgeon fed selectively on a narrow range of available prey consisting mostly of larval chironomids (93% composition by number during warm season, 96% during cool season), some genera of which they prey upon selectively, primarily Chironomus sp., but to a lesser extent Procladius, Ablabesmyia, Coelotanypus, and Cryptochironomus spp. Meanwhile, other abundant taxa in the resource base were avoided, such as Oligochaetes, Hexagenia mayflies, and the chironomid Glyptotendipes. Our results illustrate that assessing seasonally available prey from habitat utilized by lake sturgeon is important when investigating diet preference.     

Development of mesonephros in prolarvae of acipenserids (acipenseridae)

Development of the excretory system in early ontogenesis of acipenserids—the Russian sturgeon Acipenser gueldenstaedtii, the starred sturgeon A. stellatus, the sterlet A. ruthenus, and the great sturgeon Huso huso—is investigated histologically. In acipenserids, the mesonephros develops after hatching. At the 36th stage of development (after Detlaf et al., 1981), the mesonephros is a consecutively arranged group of spherical rudiments of placodes situated along the Wolffian duct. Morphological differentiation of mesonephros as the first generations of renal corpuscles, vascular glomeruli, and convoluted tubules is completed up to the 45th stage, i.e., to the moment of transition of prolarvae to active feeding.     

The peculiarities of the structural and functional state of the cytochrome component of the liver mitochondrial respiratory chain under conditions of acetaminophen-induced hepatitis on the background of alimentary protein deprivation

The activity of a key enzyme of the cytochrome component of the respiratory chain (cytochrome oxidase), the quantitative redistribution of mitochondrial cytochromes b, c ₁, c, and aa ₃, as well as the activities of the key enzymes of cytochrome heme metabolism (δ-aminolevulinate synthase and heme oxygenase) under conditions of acetaminophen-induced liver injury were studied on the background of dietary protein deprivation. Under conditions of acetaminophen-induced hepatitis that developed on the background of alimentary protein deprivation, an inhibition of cytochrome oxidase activity and a decrease in the contents of mitochondrial cytochromes on the background of an increase in the δ-aminolevulinate synthase and heme oxygenase activity were observed. In animals with a toxic liver injury that were kept under conditions of dietary protein deprivation, the contents of mitochondrial cytochromes b, c ₁, c, and aa ₃ progressively decreased, which was accompanied by an increase in heme oxygenase activity, whereas δ-aminolevulinate synthase activity remained at the control level. It was concluded that dietary protein deprivation is a critical factor for the development of disturbances in the structural-functional integrity of the cytochrome component of the respiratory chain. The identified changes can be considered as a possible mechanism that underlies the disturbance in the function of the energy biotransformation system under conditions of dietary protein deprivation.     

Genetic characterization of Amur sturgeon <Emphasis Type="Italic">Acipenser schrenckii</Emphasis> and its hybrid caught around Hokkaido

Genetic characterization was performed in five individuals of wild Amur sturgeon Acipenser schrenckii, and/or its presumed hybrid caught around Hokkaido, using a mitochondrial DNA (mtDNA) marker and two markers of nuclear DNA (nDNA). Genetic analyses indicated that two of the five fish had the mtDNA haplotype of Kaluga, Huso dauricus, whereas the nDNA markers indicated signs for both A. schrenckii and H. dauricus genotypes, referring to a hybrid origin. The other three fish were plausibly pure A. schrenckii. The results indicated the importance of combined usage of mtDNA and nDNA markers for correct species identification in sturgeon.     

Effect of Gonadotropic Hormones on Stress Resistance of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis> Females Infected with Different <Emphasis Type="Italic">Wolbachia pipientis</Emphasis> Genotypes

The effect of gonadotropic hormones (juvenile (JH) and 20-hydroxyecdysone (20E)) on heat stress resistance was for the first time studied in wild type D. melanogaster line females infected with different genotypes of the Wolbachia pipientis alpha-proteobacterium. It was found that an experimental increase in JH level induces a decrease in the heat stress resistance, while an increase in 20E level induces its increase in sixday females both uninfected with the Wolbachia and infected with different bacterium strains (wMelCS, wMelPop, and wMel). However, the intensity of response differs: a decrease in the survival with an increase in JH level and its increase with an increase in 20E level are more pronounced in females infected with pathogenic wMelPop strain and less pronounced in females infected with the wMelCS genotype than in uninfected females and females infected with the wMel genotype. Data obtained suggest that the wMelCS genotype induces a decrease and wMelPop induces an increase in the level of stress hormone (dopamine), since previously we demonstrated that an increase in the JH level in mature females increases the dopamine level, an increase in the 20E level decreases it, and an increase/decrease in the dopamine level, in turn, leads to a decrease/increase of the Drosophila female resistance to heat stress.     

<Emphasis Type="Italic">Acipensericola glacialis</Emphasis> n. sp. (Digenea: Aporocotylidae) from heart of lake sturgeon <Emphasis Type="Italic">Acipenser fulvescens</Emphasis> Rafinesque (Acipenseriformes: Acipenseridae) in the Great Lakes Basin,Lake Winnebago System,USA

Acipensericola glacialis n. sp. infects the heart of lake sturgeon, Acipenser fulvescens (Rafinesque), in the Lake Winnebago System and differs from its only congener, Acipensericola petersoni Bullard, Snyder, Jensen & Overstreet, 2008, by having a dendritic intestine, deeply-lobed testes, a post-ovarian oötype, and a common genital pore that is medial to the dextral caecum. Acipensericola petersoni has a non-dendritic intestine, testes that are not deeply lobed, an oötype that is at level of the ovary (ventral to the ovary), and a common genital pore that is dorsal to the dextral caecum. Comparison of the large (28S) and small (18S) sub-unit ribosomal DNA and internal transcribed spacer 2 (ITS2) regions between specimens of A. glacialis n. sp. and A. petersoni revealed 13 (of 1,621 nt; 99.2% similarity in the 28S), 8 (of 1,841 nt; 99.9% similarity in the 18S), and 11 (of 442 nt; 97.5% similarity in the ITS2) nucleotide differences. Collectively, these results comprise an unexpectedly high degree of morphological and molecular similarity given the geographical (Mississippi River Basin vs Great Lakes Basin) and phylogenetic (Polyodontidae vs Acipenseridae) separation of these hosts but seemingly did not reject a previous hypothesis concerning lake sturgeon dispersal from the Mississippi Refugium following the Wisconsin glaciation ~18,000 years ago. The new species is the first nominal blood fluke described from a sturgeon.     

Hemato-Immunological Responses and Disease Resistance in Siberian Sturgeon <Emphasis Type="Italic">Acipenser baerii</Emphasis> Fed on a Supplemented Diet of <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis>

A feeding trial was conducted to investigate the effects of different levels of dietary Lactobacillus plantarum on hemato-immunological parameters and resistance against Streptococcus iniae infection in juvenile Siberian sturgeon Acipenser baerii. Fish (14.6 ± 2.3 g) were fed three experimental diets prepared by supplementing a basal diet with L. plantarum at different concentrations [1 × 10⁷, 1 × 10⁸ and 1 × 10⁹ colony-forming units (cfu) g^?1] and a control (non-supplemented basal) diet for 8 weeks. Innate immune responses (immunoglobulin (Ig), alternative complement activity (ACH50) and lysozyme activity) were significantly higher in fish fed the 1 × 10⁸ and 1 × 10⁹ cfu g^?1 L. plantarum diet compared to the other groups (P < 0.05). Furthermore, fish fed on various levels of L. plantarum significantly showed higher red blood cell (RBC), hemoglobin (Hb), white blood cell (WBC) and monocyte compared to those of the control group (P < 0.05). At the end of the feeding experiment, some fish were challenged with S. iniae to quantify the level of disease resistance. The mortality after S. iniae challenge was decreased in fish fed a probiotic. These results indicated that dietary supplementation of L. plantarum improved immune response and disease resistance of Siberian sturgeon juvenile.     

Alteration of thermoregulation behavior in juvenile fish in relation to satiation level

Thermoregulation behavior of satiated and hungry juvenile sterlet Acipenser ruthenus, the Siberian sturgeon Acipenser baeri, and the goldfish Carassius auratus was studied. Significant alterations of thermoregulation behavior appear in juvenile fish one day after food deprivation. Hungry fish preferred, on average, lower temperatures, their temperature range was broader, and the locomotor activity was higher than in satiated fish.     

Development of schemes of induced mutagenesis for improving the productivity of <Emphasis Type="Italic">Aspergillus</Emphasis> strains producing amylolytic enzymes

In order to improve the biosynthesis of amylolytic enzymes by industrial Aspergillus strains, the efficiency of stepwise application of the following methods of induced mutagenesis was studied: ultraviolet (UV) irradiation, gamma irradiation, and treatment with N-methyl-N-nitro-N-nitrosoguanidine (NG). It was found that at the early stages of mutagenesis of the glucoamylase-producing A. awamori strain UV and NG, used either alone or in combination, were efficient enough as mutagenic agents, providing an increase of glucoamylase activity by 30–35 and 50–60%, respectively. At the later stages, serial UV mutagenesis and gamma-irradiation showed high efficiency for both A. awamori, and A. oryzae strains. Gamma-mutagenesis of Aspergillus strains using a cobalt source provided the most stable and highly active strains retaining 90–95% of their activity after five transfers on agar medium. The experiments resulted in significant improvement of the studied industrial strains, more than doubling activity of the target enzymes.     

Periventricular and central nuclei of the pretectal area of diencephalon of the sturgeons

Cytoarchitectonics of periventricular and central nuclei of the pretectal area was studied in four species of the sturgeons: the great sturgeon Huso huso, L., the Russian sturgeon Acipenser gъldenst?dti persicus n. kurensis, Belyaeff, the starred sturgeon Ac. stellatus, Pall., and the barbel sturgeon Ac. nudiventris, Lov.; this pretectum part has a similar structure. Study of these parts of the pretectal area was carried out by methods of Nissl and Bielshowskii modified by Viktorov. In this part of the pretectal area, nine nuclear structures were described, eight of them—nuclear; these are ventral periventricular pretectal nucleus and its dorsal component, dorsal periventricular pretectal nucleus, nucleus of medial longitudinal bundle, subcomissural organ, medial and lateral intercalate nuclei, and central and posterior pretectal nuclei. The main attention has been paid to the issue of the evolutional progression of this part of the pretectal area in the sturgeons as compared with other Actinopterygii.     

The role of thiol redox systems in the response of <Emphasis Type="Italic">Escherichia coli</Emphasis> to far-UV irradiation

Escherichia coli mutants deficient in glutathione (gshA), glutaredoxin (grxA), thioredoxin (trxA), and thioredoxin reductase (trxB) synthesis were studied with respect to their resistance to far-UV (UV₂₅₄) exposure. The trxA, trxB, and grxA mutants subjected to a short-term UV exposure were found to be more resistant to UV irradiation than the parent cells. Under the same conditions, the trxA and trxB mutants demonstrated a high level of induction of the sulA gene, a component of the SOS regulon. The mutagenic effect of long-term UV exposure of all the mutants with redox deficiencies was more pronounced than in the case of the parent strain, and the trxA and trxB mutants were found to be the least viable microorganisms. Pretreatment of the cells with low concentrations of the thiol-oxidizing agent diamide enhanced the sulA gene expression; however, high concentrations of diamide inhibited sulA expression. The data obtained indicate that the thiol redox systems of E. coli are involved in its response to far-UV irradiation.     

Stress factor-induced changes in the activity of antioxidant protective mechanisms in the wild type strain of <Emphasis Type="Italic">Neurospora crassa</Emphasis> and in its photoreceptor complex mutants

The effect of stress factors (changes in oxygen content, temperature, and illumination) on superoxide dismutase (SOD) and catalase activity, as well as on the content of thiol and disulfide groups, in low-molecular-weight compounds and proteins of Neurospora crassa mycelium was studied in the wild type strain and white collar-(wc-1) and white collar-2 (wc-2) mutants. Environmental stress factors induced the activation of both SOD and catalase, as well as an increase in the thiol level in the wild type strain of Neurospora crassa. In the wc-1 and wc-2 mutants, an increase in catalase activity and in the total thiol level was revealed; however, activation of superoxide dismutase was not observed. A decrease in the formation of disulfide bonds in the proteins of wc-1 and wc-2 mutants (as compared with the wild type strain) was recorded. These results indicate disrupted transduction of stress factor signals that promotes reactive oxygen species (ROS) formation in the WCC mutants.