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the parasitic coelenterate, polypodium hydriforme ussov, from the eggs of the american acipenseriform polyodon spathula.no significant differences in macro- and micromorphology were found between the parasitic stolon and free-living polyps of polypodium sp. obtained from infected eggs of the north american acipenseriform fish polyodon spathula and corresponding developmental stages of polypodium hydriforme ussov, parasitic in the volga sterlet (acipenser ruthenus). therefore, both the american and the european forms of polypodium belong to the species p. hydriforme ussov.197941895
[age and changes in the structure of the neurohypophysis of the sterlet, acipenser ruthenus l].the results are given of histophysiological study of neurohypophysis in sexually mature sterlets (acipenser ruthenus l.) of different age. an attention is paid to the age morphological changes of neurohypophysis and, in particular, to the number, size and topography of large and giant widenings of neurosecretory fibers, so-called gerring bodies. the relation between the frequency of gerring bodies and the age of fishes was followed. a suggestion is put forward to the effect that the appearance o ...1977882241
[localization of cells connected with different tropic functions in the hypophysis of the young of huso huso l. x acipenser ruthenus l., chondrostei].a number of histological and histochemical methods were used in order to detect different secretory cells in the hypophysis of young huso huso l. x acipenser ruthenus l., chondrostei. special attention was given to somatotropic cells. for their detection the following staining methods were used: orange g - acidic red 2c - acidic green g after fixation in the mixture of hgcl2 with formalin. in the dorsal part of the hypophysis having the appearance of vertical folds pressed into the hypophysis fr ...1976971119
evolution of the nucleolar apparatus during oogenesis in acipenseridae.evolution of the nucleoli has been followed during oogenesis in the acipenserid fishes, acipenser ruthenus (the sterlet) and a. guidenstadti (the sturgeon) using light and electron microscopes. in the ovaries of adults, the oogonial nuclei usually have a single nucleolus with an adjacent mass of paranucleolar fibrillar material. the cytoplasm of the oogonia contains two dense bodies peculiar only to gonocytes, one being electron dense and containing rna and the otherbeing electron-lucent and lac ...1976985850
[receptor cells of different types and quantitative relations between them in the organ of smell of larval and adult specimens of acipenserid fishes].three types of olfactory cells: rod-like and cone-like (flagellar olfactory cells) and filamentous (microvillar olfactory cells), which have been described previously in adult acipenseridae were found in the olfactory organ of the ten-days larval sturgeons (acipenser güldenstädti), sevrugas (acipenser stellatus) and sterlets (acipenser ruthenus). the flagellar olfactory receptors appeared to predominate in both ten-days larvae and adults of the anadromous sturgeons and sevrugas, while the microv ...19761030860
ultrastructure of neurosecretory cells at different stages of differentiation in the preoptic nucleus of immature sterlet.ultrastructure of neurosecretory cells of the preoptic nucleus in immature sterlet (acipenser ruthenus l.) was studies for the first time. the dorsal zone of the preoptic nucleus houses light, dark, and pycnomorphic neurosecretory cells, which contain varying numbers of elementary secretory granules measuring 1995 plus or minus 32 a in diameter. light cells containing numerous secretory granules with a diameter of 1707 plus or minus 27 a are predominant in the middle zone. pycnomorphic cells are ...19751124423
[electron microscopic study of the olfactory organ of the sterlet (acipenser ruthenus)].three variations of olfactory cells were found in the olfactory organ of the sterlet acipenser ruthenus. they were different in the shape of their peripheral processes: rod-shaped ones supplied with flagella and solitary microvilla; cone-shaped ones with solitary flagella and a great number of microvilla; filiform ones without flagella but with numerous microvilla and groups of centrioles in the cytoplasm of the peripheral process. the character of the structural and functional organization of t ...19751200864
[the origin and possible role of microvesicles in olfactory receptor cells].microvesicles and spherical particles have been described in the bulbs of receptor olfactory cells of acipenser ruthenus. two pathways of the origin of the above vesicles have been followed. these structures derive at the stage of differentiation from non-ciliary to ciliary cell type. the first of the pathways involves the autolysis of microfibril bundles produced during the regression of microvilli. the other one includes micropinocytosis induced on the basis of regressing microvilli. taking in ...20051231094
comparative localization of corticotropin and corticotropin releasing factor-like peptides in the brain and hypophysis of a primitive vertebrate, the sturgeon acipenser ruthenus l.the sturgeon is a primitive actinopterigian fish that, unlike modern teleosts, possess a portal vascular system that connects a true median eminence with the anterior pituitary as in mammals. the occurrence and localization of corticotropin and corticotropin releasing factor-like immunoreactivies were examined in the brain of the sturgeon (acipenser ruthenus l.) by immunocytochemistry with antisera raised against synthetic non-conjugated human corticotropin, and rat/human corticotropin releasing ...19921335041
isolation and amino acid sequence of urotensin ii from the sturgeon acipenser ruthenus.urotensin ii (uii) peptides have previously been isolated from the urophysis (the neurohemal organ of the caudal neurosecretory system) of several teleost fish, and the uii amino acid sequences have been determined. chondrostean fish, such as the acipenseridae (sturgeon), though without a distinct urophysis, also have a caudal neurosecretory system, which has been indicated by bioassay and immunological evidence to contain uii-like peptides. in the present studies, we investigated by uii radioim ...19921398021
peculiarities of the embryonic development of polypodium hydriforme ussov (coelenterata), a parasite of acipenserid oocytes."unicellular" stages (107 specimens) and multicellular stages (64 specimens) of embryogenesis of polypodium, found in 14 sterlet (acipenser ruthenus l.) females, have been studied with light microscopy, cytophotometry, and autoradiography following incubation with 3h-uridine. all stages of the embryonic development occur inside host oocytes. the "unicellular" stage includes a binucleate cell with unequally sized nuclei; separation inside it of a small cell around the smaller nucleus, i.e. transf ...19872436971
distribution of aminergic neurons in the brain of the sterlet, acipenser ruthenus (chondrostei, actinopterygii).aminergic nuclear areas were identified in the brain of acipenser ruthenus using formaldehyde-induced fluorescence (fif). one group of scattered, green fluorescent cerebrospinal-fluid (csf)-contacting neurons is located rostral to the commissura anterior. a second very prominent field of green fluorescent neurons is situated within the recessus preopticus, the recessus preopticus organ (rpo). caudal to the latter there is a group of green and yellow fluorescent csf-contacting neurons, the anteri ...19852859310
a visual pigment of the sturgeon retina.the visual pigments of hybrid sturgeon (a cross between acipenser ruthenus (male) and huso huso (female) have been studied both by the methods of incomplete partial bleaching and hplc analysis. on the basis of the results obtained the relationship between the structure of opsins and the spectral characteristics of visual pigments is discussed.19892920798
occurrence of two new goussia species in the intestine of the sterlet (acipenser ruthenus). 19862953202
vascularization of the telencephalic choroid plexus of a ganoid fish [acipenser ruthenus (l.)].the vascularization of the telencephalic choroid plexus of the sterlet acipenser ruthenus, a ganoid fish, was examined by vascular corrosion casting and by light and transmission electron microscopy. the arterial supply is from the dorsal mesencephalic artery via: 1) the ventral choroidal arteries (left and right); 2) the dorsal choroidal arteries (left and right); 3) the caudal choroidal arteries (left and right); 4) the ventral arteries of the dorsal sac; and, from the olfactory arteries, via ...19883389312
lymphoid organs in sturgeons (acipenseridae).lymphoid (lymphomyeloid) tissues in sturgeons (hybrid sturgeon, huso huso x acipenser ruthenus, and white pacific sturgeon, a. transmontanus) were investigated by dissection, histology and transmission electron microscopy. the main lymphomyeloid tissues are the thymus, the spleen, the anterior part of the kidney, the meningeal myeloid tissue, the pericardial tissue and lymphoid masses of the intestine, especially in the spiral valve. the kidney is the main hemopoietic tissue. the meningeal tissu ...19863765338
the hypothalamo-hypophysial system in acipenseridae. x. corticoliberin-like immunoreactivity in the hypothalamus and hypophysis of acipenser ruthenus l.using the unlabeled antibody peroxidase-antiperoxidase (pap) technique at the light microscopic level the distribution of immunoreactive corticoliberin has been studied in the hypothalamus and hypophysis of the sterlet. corticoliberin-containing cells have been revealed in the nucleus tuberalis and to lesser degree in the nucleus preopticus of the hypothalamus. the majority of labeled cells is located subependymally or between the ependymal cells. some dendrites of corticoliberin-containing cell ...19853902561
comparative scanning electron microscopy of the ventricular surface in four actinopterygian fishes: acipenser ruthenus, salmo gairdneri, tinca tinca and blennius sanquinolentus (pisces).the ventricular surface structure of the brains of actinopterygian fishes representing four distinct evolutionary levels was investigated by scanning electron microscopy (sem). in the chondrostean acipenser ruthenus ventricular spaces are wide and the ependymal surface is for the greater part densely covered with cilia; apart from macrophages supraependymal cells (se) are very scarce. in the teleosts salmo gairdneri, tinca tinca and blennius sanquinolentus the ventricles are slit-like, the dense ...19853989278
fine structure and vascular supply of the median eminence (me) in acipenser ruthenus (chondrostei).the fine structure and vascular supply of the median eminence (me) was studied in 57 specimens of acipenser ruthenus (chondrostei) by means of light microscopy (normal histology, horseradish-peroxidase (hrp), formaldehyde induced fluorescence (fif), scanning electron microscopy (sem) and transmission electron microscopy (tem) as well as by sem of vascular corrosion casts. light microscopy revealed that the me increases in thickness from caudal to rostral with capillaries invading the subependyma ...19854031490
a method for hypophysectomy of the sexually mature sterlet, acipenser ruthenus l., and the state of the fish after the operation.hypophysectomy was performed on sexually mature sterlets, acipenser ruthenus l., in summer and autumn. the operation usually lasted about 45 sec, but never longer than 90 sec. after the parasphenoid was stripped, an ellipsoid hole was trepanated at the level of the eyes. the hypophysis was ablated by catching its rostral end with a pincer. as the result of the extirpation of the hypophysis the majority of the specimens grew steadily lighter, and a considerable loss of the body weight as well as ...20144076766
[head blood vessels of the sterlet (acipenser ruthenus l.) (acipenseridae, chondrostei)]. 19734730634
a method for hypophysectomy in the young sturgeon acipenser ruthenus l. 20035154595
[crown cells in the diencephalon of acipenser ruthenus (acipenseridae, chondrostei)].crown cells are considered to be typical for the saccus vasculosus of gnathostome fishes. in acipenser ruthenus these cells could be found on the entire floor of the diencephalon by sem. there is one accumulation of crown cells in the frontal recessus praeopticus, one caudal to the optic chiasma and one on the floor of the recessus lateralis. the number of apical processes of the crown cells decreases significantly according to their distance from the saccus vasculosus. in all basal gnathostome ...19836672098
[interrenal tissue reaction of the hypophysectomized sexually mature sterlet (acipenser ruthenus l.) to salt exposure].to corroborate the direct influence of hypothalamic nanopeptides on the peripheral endocrine glands (the phylogenetically ancient paraadenohypophyseal pathway of regulation) under a prolonged stress as hypothesized by polenov, sexually mature male and female sterlets, intact and hypophysectomized 4 months previously were placed into 6% nacl solution for 10 days. an activation of the interrenal tissue occurred both in intact and hypophysectomized fish as evidenced by increased nuclear volume of t ...19827117622
light and electron microscopic studies on the development of sphaerospora colomani baska, 1990 and chloromyxum inexpectatum baska, 1990.during a parasitological survey conducted on sterlets (acipenser ruthenus l.), the developmental stages of two new coelozoic species of myxosporea were demonstrated in the kidney and in the urinary passages. sphaerospora colomani develops vegetative stages in the interstitial capillaries of the kidney in winter. the ultrastructure of a large primary cell containing secondary, tertiary and quaternary cells was examined. the vegetative developmental forms were located beside the tubule in the cyto ...19938116502
retinopetal projections from diencephalic neurons in a primitive actinopterygian fish, the sterlet acipenser ruthenus.horseradish peroxidase (hrp) injections into the sterlet (acipenser ruthenus) retina retrogradely label neurons in the dorso-medial thalamus, bilaterally. on the contralateral side, 5-7 cells were labelled, whereas ipsilaterally, only 2-3 cells were backfilled. such diencephalic retinopetal cells have, so far, only been found in teleosts and in tetrapods. it has, therefore, been suggested that they evolved independently in these two vertebrate groups. our findings on a primitive actinopterygian ...19938255541
dna content in eurasian sturgeon species determined by flow cytometry.the nuclear dna content in 10 species of chondrostean fishes was measured by flow cytometry. the sterlet acipenser ruthenus blood cells were used as an internal standard. the sterlet dna content was calculated on the basis of comparison with the xenopus laevis blood cells, 2c = 6.30 pg. in the tetraploid a. ruthenus and a. stellatus the dna content comprises 3.74 pg/nucleus and is practically invariant; in huso dauricus it is almost the same, 3.74-3.81 pg; and in a. nudiventris it is a little hi ...19938513694
urotensin ii from the river lamprey (lampetra fluviatilis), the sea lamprey (petromyzon marinus), and the paddlefish (polyodon spathula).urotensin ii was isolated from extracts of the whole brain of the river lamprey (lampetra fluviatilis) and the sea lamprey (petromyzon marinus). the primary structure of the peptide from both species is the same (asn-asn-phe-ser-asp-cys-phe-trp-lys-tyr-cys-val) and this amino acid sequence is identical to that of urotensin ii from the dogfish and skate. consistent with previous morphological studies indicating that the agnatha lack a caudal neurosecretory system, urotensin ii was not detected in ...19958536944
[nontraditional "large-cell" neuroendocrine formations (accessory nuclei) in the brain of anamnia and amniota].using immunochemical pap-method nonapeptidergic neuroendocrine formations in the hypothalamus and adjacent brain areas of fishes (the sterlet acipenser ruthenus, the shark scylliorhinus canicula), amphibians (the frog rana temporaria), reptiles (the snake natrix natrix), mammals (rats and dogs) and human have been studied. in amniota and human accessory nuclei (an) in addition to main "magnocellular" nuclei (supraoptic, postoptic and paraventricular) were discovered. two an, circular and dorsola ...19958714298
ig light chain gene in the siberian sturgeon (acipenser baeri).elasmobranch and teleost fish have their ig light (l) chain loci organized in multiple clusters (vl-jl-cl). the vl segments of teleosts are in opposite transcriptional orientation to the cl genes, suggesting that in teleosts and elasmobranchs there may have been separate evolutionary events leading to this organization. to address this problem, the igl locus from the siberian sturgeon (acipenser baeri) (representative of a branch between elasmobranchs and teleosts) was investigated. sequence ana ...19968757324
the hypothalamo-hypophyseal system in acipenseridae. xi. morphological and immunohistochemical analysis of nonapeptidergic and corticoliberin-immunoreactive elements in hypophysectomized sterlet (acipenser ruthenus l.).the regeneration of the hypothalamo-hypophyseal system (hhs) has been studied in the sterlet following hypophysectomy (hypox). significant portions of nonapeptide and corticoliberinergic (crh) neurosecretory cells (nscs) underwent degeneration. surviving nscs had a great regenerative ability; damaged axons formed anew, uncharacteristicly for intact fishes, axovasal and axoventricular contacts. there are some specific features of the reorganization of the anhyp in sterlet after hypox: (a) blood c ...19979073493
subdivisions of the olfactory system in the sterlet acipenser ruthenus.subdivisions of the olfactory system of the sterlet acipenser ruthenus were investigated by means of horseradish peroxidase (hrp) injections into the nose, and by soybean agglutinin binding studies. with both methods primary olfactory fibers were labeled which projected to the ventral part of the glomerular layer of the olfactory bulb. the dorsal part of the olfactory bulb did not bind soybean agglutinin, however, even though hrp tracing showed primary olfactory fibers in that area. this confirm ...19979350856
comparative immunocytochemical study of fmrfamide neuronal system in the brain of danio rerio and acipenser ruthenus during development.the distribution of fmrfamide-like immunoreactive (ir) neurons and fibers was investigated in the central nervous system of developing zebrafish and juvenile sturgeon (sterlet). adult zebrafish was also studied. in zebrafish embryos fmrfamide-ir elements first appeared 30 h post-fertilization (pf). ir somata were located in the olfactory placode and in the ventral diencephalon. fmrfamide-ir fibers originating from diencephalic neurons were found in the ventral telencephalon and in ventral portio ...200010675769
cloning of a cxcr4 homolog in chondrostean fish and characterization of the cxcr4-specific structural features.the chemokine receptor cxcr4 and its ligand sdf-1 are essential components of hematopoiesis, organogenesis and immunomodulation in mammalian species. we cloned a cdna encoding cxcr4 homolog of sterlet (acipenser ruthenus), a representative of chondrostean fishes. the deduced amino acid sequence of sterlet cxcr4 is almost equally distant from mammalian and teleost cxcr4 (66-68% identical residues). percent identity with the other chemokine receptors varies in the 30-35% range. the cxcr4 sequences ...200010906389
cd3epsilon homologues in the chondrostean fish acipenser ruthenus.cd3epsilon is an essential component of the t-cell receptor (tcr) complex for antigen. we report here molecular cloning and characterization of cdnas encoding the cd3epsilon homologues in sterlet (acipenser ruthenus), a representative of primitive chondrostean fishes. sequence analysis of the cdna clones demonstrated unexpectedly high cd3epsilon gene heterogeneity in this species. while some cdnas encoded proteins with the structure typical of mammalian cd3epsilon, others coded for proteins lack ...200011061286
the genus acipenser as a model system for vertebrate urogenital development: nephrostomial tubules and their significance for the origin of the gonad.early gonadal development was studied in the sterlet, acipenser ruthenus, by means of histological and semithin serial sections and scanning electron microscopy. special attention was given to the role of opisthonephric nephrostomial tubules and their coelomic funnels (nephrostomes, coelomostomes) in the origin of the gonad. specimens of about 1 mm in length (about 7 days post hatching) have a continuous kidney complex (holonephros) that extends from the branchial region to the level of the cloa ...200211875667
architecture of the integument in lower teleostomes: functional morphology and evolutionary implications.a bony ganoid squamation is the plesiomorphic type in actinopterygians. during evolution, it was replaced by weak and more flexible elasmoid scales. we provide a comparative description of the integument of "ganoid" fishes and "nonganoid" fishes that considers all dermal components of mechanical significance (stratum compactum, morphology of ganoid scales, and their regional differences) in order to develop a functional understanding of the ganoid integument as a whole. data were obtained for th ...200212125067
ploidy levels and the number of nuclei in cardiomyocytes of the lamprey and fish.it is well known that polyploidization of cardiomyocytes (cmc) is an essential component of heart growth in the warm-blooded vertebrates. using the feulgen cytophotometry of alkali-dissociated cells, we determined the ploidy in cmc of the lower vertebrates: lamprey lampetra fluviatilis (cyclostomata), skate bathyraja maculata (chondrostei), sterlet acipenser ruthenus, and russian sturgeon acipenser güldenstädti (ganoids), as well as paradise fish macropodus opercularis, amur sleeper perccottus g ...200212149784
distribution of gfap immunoreactive structures in the rhombencephalon of the sterlet (acipenser ruthenus) and its evolutionary implication.previous studies have revealed that although the brains of cypriniform teleosts (iberian barb, barbus comiza; carp, cyprinus carpio; goldfish, carassius auratus) are rich in glial fibrillary acidic protein (gfap), they have, however, areas devoid of gfap immunoreactivity. the largest ones of these are in the rhombencephalon, e.g., the zones of the sensory and motor neurons in the vagal lobe. our studies in amniotes suggested that the gfap immunonegative areas could be characteristic of the more ...200212210122
the genus acipenser as a model for vertebrate urogenital development: ultrastructure of nephrostomial tubule formation and of initial gonadogenesis.the ultrastructure of the nephrostomial tubule and the gonadal crest of acipenser ruthenus were studied by transmission and scanning electron microscopy. opisthonephric nephrostomial tubules begin to appear at the end of the first week after hatching and are regularly segmentally arranged and completely developed in the period between 10 and 35 days after hatching. fully differentiated nephrostomial tubules connect the vestibular area of the malpighian corpuscle with the coelomic cavity as short ...200212392324
the genus acipenser as a model for vertebrate urogenital development: the müllerian duct.the development of the müllerian duct was studied in a total of 85 specimens of acipenser ruthenus and acipenser baeri in the period from 7 days after hatching through 5 years of age. normal histology on serial sections, transmission and scanning electron microscopy and bromodeoxyuridine immunohistochemistry were applied. in acipenser, the primary set of opisthonephric nephrons possess short nephrostomial tubules with well-developed nephrostomes. proliferating cells from the lateral side of the ...200312649724
early development of the olfactory organ in sturgeons of the genus acipenser: a comparative and electron microscopic study.formation and morphology of the olfactory organ of vertebrates has been intensely studied in some taxa for more than a century. as a functionally important and complex sensory organ, its ontogenetic development has often been a matter of debate on higher-level craniate evolution. however, sufficient knowledge of structure and development of the olfactory organ in the crucial taxa needed for a serious phylogenetic reasoning is generally not available. this study aims at this essential primary dat ...200312684762
[polypodium hydriforme in the eggs of the sterlet from the northern dvina river].the paper provides data on the invasion of acipenser ruthenus (sterlet) in the north dvina river by polypodium hydriforme (cnidaria). prevalence and intensity of invasion proved to be similar for two fishing sites. prevalence of invasion exceeded 88%, thus being exceptionally high for p. hydriforme. intensity of invasion was from 1 to 436 eggs per female. a verage percentage of infected eggs was about 1%.200312815815
[electron microscopy study of the frontal neurohypophysis of the sterlet acipenser ruthenus]. 200612815976
chromosomal mapping of 18s-28s and 5s rrna genes by two-colour fluorescent in situ hybridization in six sturgeon species.the number and distribution of the 18s-28s and 5s rrna (rdna) gene sequences were examined on mitotic chromosomes of six sturgeon species by two-colour in situ hybridization. four of the six species, huso huso, acipenser stellatus, acipenser sturio, and acipenser ruthenus, with about 120 chromosomes, showed from six to eight 18s-28s rdna signals, while 5s rdna signals were on only one chromosome pair. the two species with 250-270 chromosomes, acipenser baerii and acipenser transmontanus, showed ...200312834065
[histologic studies on the gonads, thyroid gland, and pituitary in acipenser ruthenus in natural conditions in ponds and rivers]. 195313095293
detection of mycobacteria in aquarium fish in slovenia by culture and molecular methods.thirty-five aquarium fish were investigated for the presence of mycobacteria by culture and molecular methods. the following species were examined: goldfish carassius auratus auratus, guppy poecilia reticulata, 4 three-spot gourami trichogaster trichopterus, dwarf gourami colisa lalia, siamese fighting fish betta splendens, freshwater angelfish pterophyllum scalare, african cichlid fish cichlidae spp., cichlid fish microgeophagus altispinosus, cichlid fish pseudotropheus lombardoi, blue streak h ...200515900685
analysis of microvascular trees by means of scanning electron microscopy of vascular casts and 3d-morphometry.arterial and capillary trees form by consecutive branching (mostly bifurcations) from a stem vessel, venous trees form by repeated merging of blood vessels. diameters of stem (parent, mother) vessels and daughter vessels (branches), interbranching distances and branching angles between stem and daughter vessels lastly define the overall three-dimensional structure of the vascular network as well as the basic transport capacity of the system. here we use scanning electron microscopy and 3d-morpho ...200516101025
assessing pollution in the danube river near novi sad (serbia) using several biomarkers in sterlet (acipenser ruthenus l.).the response of wild fish to pollutants was studied in sterlet (acipenser ruthenus l.) collected in 2001 and 2002 at two sampling sites in the danube river near novi sad (serbia): in the vicinity of the oil refinery and at the danube-begec, remote from the oil refinery and considered a reference site. the following biomarkers were measured in sterlet collected from these two sites: the activities of superoxide dismutase (sod), catalase, glutathione peroxidase (gsh-px), and glutathione s-transfer ...200616194569
the role of the igf-i system for vitellogenesis in maturing female sterlet, acipenser ruthenus linnaeus, 1758.transition from previtellogeneic to vitellogenic oocyte growth is a critical phase for folliculogenesis in sturgeon and may often be postponed for several years. recent findings on the involvement of insulin-like growth factor i (igf-i) in cell differentiation processes of oocyte follicle and ovarian steroidogenesis of teleosts in vitro led to the hypothesis that paracrine igf-i could function as a potential trigger in vivo. for the first time, igf-i and its corresponding receptor (igf-ir) were ...200716945369
design of cerebellar and nontegmental rhombencephalic microvascular bed in the sterlet, acipenser ruthenus: a scanning electron microscope and 3d morphometry study of vascular corrosion casts.the design of the microvasculature of cerebellum and nontegmental rhombencephalic areas was studied in eight adult acipenser ruthenus l. by scanning electron microscopy of vascular corrosion casts and three-dimensional morphometry. gross vascularization was described and diameters and total branching angles of parent and daughter vessels of randomly selected arterial and capillary bifurcations (respectively, venous mergings) were measured. with diameters ranging from 15.9 +/- 1.9 microm (cerebel ...200616984664
immunoglobulin heavy chain constant region of five acipenseridae: cdna sequence and evolutionary relationship.the immunoglobulin m (igm) heavy chain constant region genes of russian sturgeon (acipenser gueldenstaedtii), sterlte sturgeon (acipenser ruthenus), amur sturgeon (acipenser schrenckii), chinese sturgeon (acipenser sinensis) and great sturgeon (huso huso) were cloned and analyzed with molecular biology and bioinformatics methods. we cloned igh nucleic acid sequences by rt-pcr using the specific primer, then determined the characteristics and functions of the amino acid sequences. the gene contai ...200717234432
expression of igf-i and igf-i receptor in male and female sterlet, acipenser ruthenus--evidence for an important role in gonad maturation.recent in vitro studies suggest that insulin-like growth factor i (igf-i) is involved in cell differentiation and steroidogenesis in the gonad and could therefore function as an important trigger in vivo. in this study, sensitive real-time rt-pcr assays were used to determine igf-i and the igf-i receptor (igf-ir) mrna expression in maturing male and female sterlet (acipenser ruthenus) over a period of two years: in the first year, females entering vitellogenesis (maturing female group, mfg) reve ...200717289414
fine structure and morphology of sterlet (acipenser ruthenus l. 1758) spermatozoa and acrosin localization.ultrastructure of sterlet acipenser ruthenus l. 1758 sperm was examined by scanning and transmission electron microscopy, which allowed us to use various methods for visualizations of different parts of sterlet spermatozoa. sperm cells possess a head with a distinct acrosome, a midpiece and a single flagellum surrounded by the flagellar plasma membrane. the average length of the head including the acrosome and the midpiece was estimated as 5.14+/-0.42 microm. nine to 10 posterolateral projection ...200918359585
acrosome staining and motility characteristics of sterlet spermatozoa after cryopreservation with use of methanol and dmso.in this study we describe acrosome staining and motility characteristics of fresh and cryopreserved sterlet (acipenser ruthenus l.) spermatozoa using soybean trypsin inhibitor-alexa conjugate fluorescent staining and computer-aided sperm analysis (casa), respectively. methanol or dimethylsulfoxide (dmso) were used as cryoprotectants. after cryopreservation a decline in sperm motility characteristics occurred, but no differential effect between cryoprotectant was observed. cryopreservation caused ...200818466892
chromosomal nucleolar organizer regions in four sturgeon species as markers of karyotype evolution in acipenseriformes (pisces).nucleolar organizer regions in acipenser ruthenus (2n = 118 +/- 4) are localized on the telomeric regions of two morphologically different pairs of chromosomes. in a. baeri (2n = 250 +/- 8), a. transmontanus (2n = 248 +/- 8), and a. naccarii (2n = 246 +/- 8) they are localized on eight chromosomes arranged in two quadruplets. contrary to what is commonly accepted, such distribution suggests that species with 120 chromosomes should be considered diploids and species with 240-250 chromosomes shoul ...199418470132
size determination of acipenser ruthenus spermatozoa in different types of electron microscopy.in this study three types of scanning electron microscopes were used for the size determination of spermatozoa of sterlet acipenser ruthenus - high vacuum scanning electron microscope (sem, jeol 6300), environmental scanning electron microscope (esem, quanta 200 feg), field emission scanning electron microscope (fesem, jeol 7401f) with cryoattachment alto 2500 (gatan) and transmission electron microscope (tem, jeol 1010). the use of particular microscopes was tied with different specimen prepara ...201020226681
[buffer, respiratory properties, and ion surrounding of hemoglobin in the sterlet acipenser ruthenus]. 201620583587
image cytometric measurements of diploid, triploid and tetraploid fish erythrocytes in blood smears reflect the true dimensions of live cells.comparative image cytometry of erythrocytes of diploid and triploid tench tinca tinca l. and evolutionary tetraploid sterlet acipenser ruthenus l. was performed on whole live unstained cells, live cells with stained nuclei and on stained fixed whole cells and their nuclei to test if erythrocyte measurements made from blood smears reflect the true dimensions of live cells. nuclear area and perimeter were the best ploidy level predictors distinguishing accurately among live and fixed diploid, trip ...201120812918
liver, gills, and skin histopathology and heavy metal content of the danube sterlet (acipenser ruthenus linnaeus, 1758).the sterlet (acipenser ruthenus l.) is a bottom-feeding fish species with a direct exposure to contaminants from water and sediments. although heavy metal pollution is believed to be one of the main threats to the sterlet population in the danube river basin, there is a lack of knowledge of the exact impact of heavy metals on their survival. in the present study, effects of heavy metal pollution on sterlet in the danube basin were assessed as well as the utility of different sterlet organs and t ...201020821473
influence of environmental related concentrations of heavy metals on motility parameters and antioxidant responses in sturgeon sperm.the effects of heavy metals (cd, cr and cd+cr) on the motility parameters and oxidative stress of sterlet (acipenser ruthenus) sperm were investigated in vitro. sturgeon sperm were exposed for 2h to heavy metals at environmental related concentrations (0.1mgl(-1) cr, 0.001mgl(-1) cd, 0.1mgl(-1) cr+0.001mgl(-1) cd) and higher concentrations (5.0mgl(-1) cr, 0.05mgl(-1) cd, 5.0mgl(-1) cr+0.05mgl(-1) cd). results revealed that environmental concentrations of heavy metals had no significant influence ...201020836996
non-dioxin-like pcbs in ten different fish species from the danube river in serbia.this work has been developed to examine the level of non-dioxin-like (ndl) pcbs (28, 52, 101, 138, 153 and 180) in (a) ten different freshwater fish species from the danube river, (b) two sampling points: up and downstream of the industrial zone of the city of pancevo (ecological hot spot in serbia) and (c) two time points i.e., in 2001 and 2006. obtained results would serve to analyse spatial, temporal and congener profile characteristics of ndl pcbs cumulated in fish tissues due to environment ...201021161586
roles of osmolality, calcium - potassium antagonist and calcium in activation and flagellar beating pattern of sturgeon sperm.the present study shows the roles of osmolality, calcium (ca(2+))-potassium (k(+)) antagonist and ca(2+) in sperm activation and flagellar beating of a sturgeon species, sterlet (acipenser ruthenus). sperm motility was activated at hypoosmolality relative to seminal plasma and suppressed at 175 mosmol kg(-1). sperm activation was totally suppressed by 0.35mm k(+), but ca(2+) could fully reverse k(+) inhibitory effect at ca(2+): k(+) ratio of 0.25. neither egta (a chelator of ca(2+) ions) nor nif ...201121651987
evaluation of spermiation indices with multiple sperm collections in endangered sterlet (acipenser ruthenus).this study investigated the effects of multiple collections of sperm on endangered sterlet (acipenser ruthenus) sperm functional parameters [spermatozoa motility and curvilinear velocity (vcl)] as well as on protein concentration and osmolality of seminal plasma. the average sperm volume and mean spermatozoa concentration per male were significantly altered with multiple collections. on the other hand, no significant effect of multiple collections on protein concentration of seminal plasma was o ...201221978021
Lactococcus lactis subsp. lactis infection in Bester sturgeon, a cultured hybrid of Huso huso×Acipenser ruthenus, in Taiwan.Approximately 5300 hybrid sturgeons with an average body weight of 600-800g were farmed in 3 round tankers measuring 3m in diameter each containing 28,000L of aerated groundwater. According to the owner's description, the diseased fish had anorexia, pale body color, and reddish spots on the abdomen. The morbidity and lethality rates in this outbreak were about 70% (3706/5300) and 100% (3706/3706), respectively. The clinical examination revealed enteritis, enlarged abdomen, and rapid respiration ...201122098776
[the influence of testosterone on activity of glycosidases and proteinases in the intestine of the sterlet (acipenser ruthenus)].observation of the influence oftestosterone (0.7 mg/kg) on the activity ofglycosidases and proteinases, which function in the chime and the mucous coat of the sterlet intestine (acipenser ruthenus), revealed a decrease in enzyme activity of both chains as against that one typical for intact individuals. the activity of the investigated enzymes changes in both the experimental and control groups offish. nevertheless, they have unlike dynamics of this activity. in a number of cases, we indicated a ...201622117424
sperm characteristics and androgens in acipenser ruthenus after induction of spermiation by carp pituitary extract or gnrha implants.spermiation and changes in androgen (testosterone, t and 11-ketotestosterone, 11-kt) levels were studied in sterlet (acipenser ruthenus) treated with gnrh agonist implants (dala(6)-pro(9)-lhrha) at 25 and 75 μg kg(-1) b.w. and compared with those males treated with 4 mg kg(-1) b.w. of carp pituitary extract (cpe) and 3 pellets of ovopel kg(-1) b.w., which contains dala(6)-pro(9)net-mgnrh and metoclopramide. sperm quality (sperm mass, spermatozoa concentration and sperm motility and velocity) was ...201222665160
comparison of protein fractions in seminal plasma from multiple sperm collections in sterlet (acipenser ruthenus).seminal plasma of sterlet acipenser ruthenus was evaluated using comparative proteomics to characterize its protein fractions and to determine any influence of multiple sperm collections on these proteins. an experimental group of fish was used, in which sperm was collected three times at 5 h intervals. protein fractions of seminal plasma were determined by sds-gel electrophoresis (sds-page) and two-dimensional electrophoresis high-resolution gels (2d). at all stripping times, five protein bands ...201322747924
evidence for a divergence in function between two glucocorticoid receptors from a basal teleost.duplicated glucocorticoid receptors (gr) are present in most teleost fish. the evolutionary advantage of retaining two grs is unclear, as no subtype specific functional traits or physiological roles have been defined. to identify factors driving the retention of duplicate grs in teleosts, the current study examined grs in representatives of two basal ray-finned fish taxa that emerged either side of the teleost lineage whole genome duplication event (wgd) event, the acipenseriform, acipenser ruth ...201222862956
different swimming behaviors of sterlet (acipenser ruthenus) spermatozoa close to solid and free surfaces.spermatozoa tend to swim near surfaces. such attraction toward surface vicinity was approximated by the force-dipole theoretical approach and hydrodynamic modeling, but the physical parameters of surfaces have not usually been included in these models and their effect on sperm mobility remains unknown. in spermatozoa, changes in wave parameters, together with rotation around their longitudinal axis and circling appear when movement takes place close to surfaces. here we show, by analysis of micr ...201323102849
developmental structure of the vertebral column, fins, scutes and scales in bester sturgeon, a hybrid of beluga huso huso and sterlet acipenser ruthenus.in the larval bester, a hybrid sturgeon of beluga huso huso and sterlet acipenser ruthenus, development of cartilage around the notochord began 7 days post hatch (dph) (14.0 mm, total length, l(t)). the vertebral cartilage develops in the following sequence: basidorsals and basiventrals, neural canals, neural spines and ribs. the development of ribs remained incomplete in the largest specimen (181 dph, 179 mm l(t) ) that was examined. endoskeletal development of the fins began 4 dph for the dors ...201223130694
site heteroplasmy in the mitochondrial cytochrome b gene of the sterlet sturgeon acipenser ruthenus.sturgeons are fish species with a complex biology. they are also characterized by complex aspects including polyploidization and easiness of hybridization. as with most of the ponto-caspian sturgeons, the populations of acipenser ruthenus from the danube have declined drastically during the last decades. this is the first report on mitochondrial point heteroplasmy in the cytochrome b gene of this species. the 1141 bp sequence of the cytb gene in wild sterlet sturgeon individuals from the lower d ...201223271951
influence of environmentally relevant concentrations of vinclozolin on quality, dna integrity, and antioxidant responses of sterlet acipenser ruthenus spermatozoa.the effects of vinclozolin (vin), an anti-androgenic fungicide, on quality, oxidative stress, dna integrity, and atp level of sterlet (acipenser ruthenus) spermatozoa were investigated in vitro. fish spermatozoa were incubated with different concentrations of vinclozolin (0.5, 2, 10, 15, 20 and 50 μg/l) for 2 h. a dose-dependent reduction in spermatozoa motility and velocity was observed at concentrations of 2-50 μg/l. a dramatic increase in dna fragmentation was recorded at concentrations 10 μg ...201323376258
first evidence of autotriploidization in sterlet (acipenser ruthenus).polyploidization has played an important role in vertebrate evolution. acipenseridae bring clear examples of polyploidy ancestry and, also, polyploidization seems to be an ongoing process in these fishes. in the present study, the genetic origin of six triploid specimens morphologically determined as acipenser ruthenus from commercial aquaculture was analyzed using a combination of mitochondrial and nuclear markers. a further five successive statistical analyses including median joining of mitoc ...201323456847
motility of sturgeon spermatozoa can sustain successive activations episodes.here we report for the first time the possibility of sequential sperm motility activation in sturgeon (sterlet, acipenser ruthenus), a fish with external fertilization, through changes either in osmolality (global solute concentration) or in the ca(2+) concentration of the medium surrounding the spermatozoa. sperm motility was initiated in any of three solutions containing buffer and sucrose at 80, or 40 or 10mm (called s80, s40, s10, respectively); s80 is hypertonic relative to sterlet seminal ...201323528713
the in vitro effect of duroquinone on functional competence, genomic integrity, and oxidative stress indices of sterlet (acipenser ruthenus) spermatozoa.the sturgeon is a highly endangered fish species mostly due to over-fishing, habitat destruction, and water pollution. duroquinone (derivative of 1,4-benzoquinone) is a xenobiotic compound widespread in the environment. the effect of duroquinone on motility, dna integrity, and oxidative stress indices in sterlet, acispenser ruthenus, spermatozoa was investigated. sterlet sperm was exposed for 2h to duroquinone at concentrations of 25, 50, 100, and 150 μm. spermatozoa motility, velocity, and atp ...201323587503
in vitro effects of bisphenol a on the quality parameters, oxidative stress, dna integrity and adenosine triphosphate content in sterlet (acipenser ruthenus) spermatozoa.among endocrine disruptors, the xenoestrogen bisphenol a (bpa) deserves particular attention due to widespread human exposure. besides hormonal effects, bpa has been suspected to be responsible for adverse effect on reproductive ability of various species. in the present study the effect of bpa on the quality parameters, oxidative stress, the dna integrity and intracellular atp content of sterlet (acipenser ruthenus) spermatozoa were investigated in vitro. fish spermatozoa were exposed to concen ...201323680852
lateralisation of rotational swimming but not fast escape response in the juvenile sterlet sturgeon, acipenser ruthenus (chondrostei: acipenseridae).for the first time, behavioural lateralisation was shown in a chondrostean fish (sterlet sturgeon acipenser ruthenus). a significant directional bias was found in young a. ruthenus swimming along a circular swimway. this laterality manifested itself as an individual preference for a certain movement direction (either clockwise or counterclockwise) which was consistent at the retest 10 days later. on the other hand, no significant rotational bias was observed at the population level. the same ste ...201423758344
[determination of 17 amino acids in fish eggs by ultra performance liquid chromatography coupled with precolumn derivatization].a rapid quantitative method of ultra performance liquid chromatography (uplc) has been developed for the analysis of 17 amino acids in fish eggs from acipenser schrenckii, huso dauricus and acipenser ruthenus. the analytes were hydrolyzed with 6 0 mol/l hci. the extraction solution was concentrated under low pressure and neutralized with naoh solution before derivatization with 6-aminoquinolyl-n-hydroxy-succinimidyl carbamate (aqc) as derivatization agent in borate buffer solution (ph 8.8). grad ...201323786002
different computer-assisted sperm analysis (casa) systems highly influence sperm motility parameters.in this study, we examined different computer-assisted sperm analysis (casa) systems (crismas, hobson sperm tracker, and image j casa) on the exact same video recordings to evaluate the differences in sperm motility parameters related to the specific casa used. to cover a wide range of sperm motility parameters, we chose 12-second video recordings at 25 and 50 hz frame rates after sperm motility activation using three taxonomically distinct fish species (sterlet: acipenser ruthenus l.; common ca ...201323932168
complete mitochondrial genome of sterlet (acipenser ruthenus).the complete mitochondrial genome of sterlet (acipenser ruthenus) was determined in this study. the mitogenome is 16,790 bp in length and contains 13 protein-coding genes, 22 transfer rna genes, 2 ribosomal rna genes and 2 non-coding regions (the control region and the putative origin of the light strand replication) with a typical vertebrate mitochondrial gene arrangement. the overall base composition of the heavy strand is 30.26% for a, 29.00% for c, 16.23% for g and 24.51% for t, with a sligh ...201524021000
molecular cytogenetics in artificial hybrid and highly polyploid sturgeons: an evolutionary story narrated by repetitive sequences.we applied comparative genomic hybridization (cgh) and genomic in situ hybridization (gish) to examine genomes of artificially produced sturgeon hybrids between sterlet, acipenser ruthenus female (∼120 chromosomes) or russian sturgeon, a. gueldenstaedtii female (∼240 chromosomes) and a spontaneous triploid siberian sturgeon a. baerii male (∼360 chromosomes), respectively. the ploidy levels of progenies were analyzed by karyotyping and flow cytometry. we found that the species-specific regions we ...201324051427
fertility of a spontaneous hexaploid male siberian sturgeon, acipenser baerii.evolution of sturgeons and paddlefishes (order acipenseriformes) is inherently connected with polyploidization events which resulted in differentiation of ploidy levels and chromosome numbers of present acipenseriform species. moreover, allopolyploidization as well as autopolyploidization seems to be an ongoing process in these fishes and individuals with abnormal ploidy levels were occasionally observed within sturgeon populations. here, we reported occurrence of siberian sturgeon (acipenser ba ...201424410899
3-d structure, volume, and dna content of erythrocyte nuclei of polyploid fish.we have explored the potential relationship between ploidy level, dna content (pg dna nucleus(-1)), and dimensional characteristics, such as volume (μm(3)), surface area (μm(2)), and 3-d structure of erythrocyte nuclei in a series of fish ploidy level models using feulgen image analysis densitometry, flow cytometry, and confocal laser scanning microscopy. the species were diploid tench (tinca tinca) (2n), cuban gar (atractosteus tristoechus) (2n), triploid tench (3n), evolutionary tetraploid ste ...201424446105
effects of tetrabrombisphenol a on dna integrity, oxidative stress, and sterlet (acipenser ruthenus) spermatozoa quality variables.the sperm of sterlet (acispenser ruthenus) was used to investigate the effect of the xenobiotic tetrabrombisphenol a (tbbpa) on sperm quality variables (atp content, spermatozoa motility, and velocity), dna integrity, and oxidative stress indices. sperm was diluted to obtain a spermatozoa density of 5 × 10(8) cells/ml and exposed for 2 h to final concentrations of tbbpa (0.5, 1.75, 2.5, 5, and 10 μg/l). the oxidative stress indices, including lipid peroxidation, carbonyl derivatives of proteins, ...201524459015
protease in sturgeon sperm and the effects of protease inhibitors on sperm motility and velocity.in mammals, proteases are present in sperm acrosome and play key role in fertilization. sturgeon sperm has an acrosome, but its physiology, biochemistry, and potential role in fertilization are unknown. in the present study, we have observed high protease activity in acidic extract of intact sperm compared to that of seminal plasma in sterlet (acipenser ruthenus). the protease activity was decreased and increased in acidic extract of motility-activated sperm and in the activation medium, respect ...201424677048
use of histopathology and elemental accumulation in different organs of two benthophagous fish species as indicators of river pollution.the bottom feeding fish species have a good potential to be used for assessments of pollution, as they are under pressure from pollutants from both water and sediments. in this study, the level of similarity of histopathological responses to pollution in gills and liver between barbel (barbus barbus) and sterlet (acipenser ruthenus) from the danube river was assessed, and compared with elemental concentrations in their gills, liver, and muscle. results indicate that the detected metal concentrat ...201524677754
biochemical characterisation and assessment of fibril-forming ability of collagens extracted from bester sturgeon huso huso × acipenser ruthenus.collagens purified from bester sturgeon organs were characterised biochemically, and their fibril-forming abilities and fibril morphologies formed in vitro clarified. yields of collagens were 2.1%, 11.9%, 0.4%, 18.1%, 0.4%, 0.8% and 0.03% (collagen dry weight/tissue wet weight) from scales, skin, muscle, swim bladder, digestive tract, notochord and snout cartilage, respectively. using sds-page and amino acid composition analyses, collagens from scales, skin, muscle, the swim bladder and digestiv ...201424799243
in vitro sperm maturation in sterlet, acipenser ruthenus.the aim of the study was to examine sperm maturation in sturgeon and to establish the localization of the maturation. we demonstrated that sperm maturation occurs in sturgeon outside the testes via dilution of sperm by urine. the process involves the participation of high molecular weight (>10kda) substances and calcium ions.201424856476
effects of dietary garlic extracts on whole body amino acid and fatty acid composition, muscle free amino acid profiles and blood plasma changes in juvenile sterlet sturgeon, acipenser ruthenus.a series of studies were carried out to investigate the supplemental effects of dietary garlic extracts (ge) on whole body amino acids, whole body and muscle free amino acids, fatty acid composition and blood plasma changes in 6 month old juvenile sterlet sturgeon (acipenser ruthenus). in the first experiment, fish with an average body weight of 59.6 g were randomly allotted to each of 10 tanks (two groups of five replicates, 20 fish/tank) and fed diets with (0.5%) or without (control) ge respec ...201225049498
effects of dietary garlic extract on growth, feed utilization and whole body composition of juvenile sterlet sturgeon (acipenser ruthenus).this study was carried out to investigate the supplemental effects of dietary garlic extract (ge) on growth performance of juvenile sterlet sturgeon (acipenser ruthenus). the first experiment was designed to determine the optimum levels of garlic extract as growth promoter during 10 weeks. three groups (two replicates/group) of 240 fish with mean body weight of 85 g were fed with diets containing 0 (control), 0.5 and 1.0% of ge. the highest weight gain (%) and feed efficiency (%) were found in f ...201225049599
motility and fertilization ability of sterlet acipenser ruthenus testicular sperm after cryopreservation.sturgeon spermatozoa are immotile in the testis and acquire the potential for motility after contact with urine in wolffian duct. the present study tested if in vitro incubation of testicular sperm in seminal fluid from wolffian duct sperm leads to the acquisition of sperm fertilization ability. sterlet sperm was taken from the testes, matured in vitro and cryopreserved. the fertility and motility of cryopreserved semen were tested. matured testicular sperm showed freeze-thaw survival rates simi ...201425058859
commercial fish species of inland waters: a model for sustainability assessment and management.the permanent increase in the exploitation of commercial fish species has led to the need for developing practical and effective tools for the sustainability assessment and management of the target fish populations. the aim of this study was to formulate an eshippofishing model which would provide a reliable assessment of commercial fish population sustainability and indicate the conservation priorities. the existing eshippo model was modified by introducing a new index of local sustainability o ...201425170830
effects of dietary garlic powder on growth, feed utilization and whole body composition changes in fingerling sterlet sturgeon, acipenser ruthenus.a 12 week growth study was carried out to investigate the supplemental effects of dietary garlic powder (gp) on growth, feed utilization and whole body composition changes of fingerling sterlet sturgeon acipenser ruthenus (averaging weight, 5.5 g). following a 24-h fasting, 540 fish were randomly distributed to each of 18 tanks (30 fish/tank) under a semi-recirculation freshwater system. the gp of 0.5% (gp0.5), 1% (gp1), 1.5% (gp1.5), 2% (gp2) and 3% (gp3) was added to the control diet (gp0) con ...201425178374
[ultrastructural characteristics of the vitellaria, uterus and vagina of amphilina foliacea rudolphi, 1819 (cestoda: amphilinidea)].the ultrastructural features of the vitelline follicles, uterus and vagina of the amphilinid cestode amphilina foliacea from the body cavity of acipenser ruthenus of the volga basin are described. some new distinguishing characters are revealed, including the presence of a single type of the cellular component in the vitelline follicles with sarcoplasmic processes filling the space around and within vitellocytes. the,uterus of this species is recognized by the presence of the syncytial epithelia ...201425464739
[ultrastructural characteristics of the vitellaria, uterus and vagina of amphilina foliacea rudolphi, 1819 (cestoda: amphilinidea)].the ultrastructural features of the vitelline follicles, uterus and vagina of the amphilinid cestode amphilina foliacea from the body cavity of acipenser ruthenus of the volga basin are described. some new distinguishing characters are revealed, including the presence of a single type of the cellular component in the vitelline follicles with sarcoplasmic processes filling the space around and within vitellocytes. the,uterus of this species is recognized by the presence of the syncytial epithelia ...201425508370
isolation and transplantation of sturgeon early-stage germ cells.we report, for the first time, a series of baseline techniques comprising isolation and transplantation of female and male early-stage germ cells in sturgeon to generate a germline chimera as a potential tool for surrogate reproduction and gene banking. cells were dissociated from testis, characterized by mostly spermatogonia, and from ovary, exclusively comprising oogonia and previtellogenic oocytes, of acipenser baerii, using 0.3% trypsin (2 hours, 23 °c) dissolved in pbs, isotonic with blood ...201525559841
motility initiation of sterlet sturgeon (acipenser ruthenus) spermatozoa: describing the propagation of the first flagellar waves.in the present study, for the first time in fish spermatozoa, we describe the precise chronology of motility initiation of sterlet (sturgeon) sperm from completely immotile flagella to regular full wave propagation. the successive activation steps were investigated by high-speed video microscopy, using specific experimental situation, where sperm motility initiation was delayed in time up to several seconds (10 ± 2.68 seconds). starting from fully immotile, the flagellum shows some trembling for ...201525794841
activation of the albino sterlet acipenser ruthenus eggs by uv-irradiated bester hybrid spermatozoa to provide gynogenetic progeny.meiotic gynogenesis was induced in the albino form of sterlet acipenser ruthenus by activation of eggs with uv-irradiated bester (huso huso x acipenser ruthenus) spermatozoa followed by inhibition of the second meiotic division performed by a heat shock. obtained putative gynogenetic progeny were all albinos. the genetic verification based on three microsatellite dna markers confirmed the only maternal inheritance of the progeny from the gynogenetic experimental groups. cytogenetic analysis prov ...201525858073
bioaccumulation of heavy metals and microelements in silver bream (brama brama l.), northern pike (esox lucius l.), sterlet (acipenser ruthenus l.), and common carp (cyprinus carpio l.) from tisza river, serbia.the aim of this study was to determine the concentrations of al, as, b, cd, co, cr, cu, fe, hg, mn, ni, pb, se, sr, and zn in liver, gills, gonads, and brain of four ecologically different fish species in serbia: piscivorous northern pike, benthivorous sterlet and silver bream, and omnivorous common carp. fish were caught at four sites along the stretch of the river tisza in the pannonian part of serbia during october 2010. results revealed that heavy metals and microelements with the highest va ...201526039743
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