The Experts below are selected from a list of 159 Experts worldwide ranked by ideXlab platform
O. A. Timoshkin - One of the best experts on this subject based on the ideXlab platform.
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First data on the endemic fauna of Turbellaria proseriata (Platyhelminthes, Otomesostomidae) from Lake Baikal
Biology Bulletin, 2010Co-Authors: O. A. Timoshkin, A. G. Lukhnev, E. P. ZaytsevaAbstract:Illustrated descriptions of the representatives of the new genus Baikalotomesostoma and two new species of Turbellaria Proseriata from Lake Baikal are given. The pattern of their morphological organization allows considering them as representatives of the Otomesostomidae family. The most important generic character of the new genus is the presence of another (the third one) sexual opening (continuing into the blint, sack-shaped organ — bursa?) located between the male and female sexual openings. According to the morphological structure, the second new species is a true representative of the Otomesostoma genus, but it is a real giant among freshwater Proseriata. This discovery of the new species and the new genus, having such a peculiar morphological structure, should be considered as evidence of the existence of another endemic species flock of free-living flatworms — Turbellaria Proseriata. Evidently, the new taxa of Lake Baikal are closely related to the Holarctic Otomesostoma auditivum Du Plessis 1874.
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Turbellaria lecithoepitheliata morphology systematics phylogeny
Hydrobiologia, 1991Co-Authors: O. A. TimoshkinAbstract:A review of the literature on the world fauna of Lecithoepitheliata and Prolecithophora and extensive observations by the author on species of the Prorhynchidae, including cosmopolitan species as well as some endemic to Lake Baikal, and on endemic species of Baicalarctiinae (Prolecithophora) show that the Prorhynchidae and Gnosonesimidae are properly classified in the Neoophora. The morphological similarity of the Prorhynchidae and Prolecithophora proves these taxa are closely related. A hypothesis relating the Lecithoepitheliata Prorhynchidae to primitive prolecithophorans appears to be the only tenable hypothesis on the phylogeny of Lecithoepitheliata. The question of whether the Lecithoepitheliata is monophyletic still needs investigation; more evidence on the phylogeny of the Gnosonesimidae is needed.
Melita Peharda - One of the best experts on this subject based on the ideXlab platform.
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reaction of the mussel mytilus galloprovincialis bivalvia to eugymnanthea inquilina cnidaria and urastoma cyprinae Turbellaria concurrent infestation
Journal of Invertebrate Pathology, 2012Co-Authors: Ivona Mladineo, Mirela Petric, Jerko Hrabar, Ivana Bocina, Melita PehardaAbstract:Abstract In total 480 individuals of Mytilus galloprovincialis were sampled monthly from October 2009 to September 2010, at the shellfish farm in the Mali Ston Bay, south Adriatic Sea (Croatia) in order to assess the extent of pathology imposed by two parasites, Eugymnanthea inquilina (Cnidaria) and Urastoma cyprinae (Turbellaria). Although a deteriorating impact on host reproduction or condition index was lacking, we evidenced ultrastructural and functional alteration in host cells at the attachment site. Ultrastructural changes included hemocytic encapsulation of the Turbellarian and cell desquamation in medusoid infestation. Caspase positive reaction inferred by immunohistochemistry (IHC) was triggered in cases of Turbellarian infestation, in contrast with hydroids, suggesting that the former exhibits more complex host–parasite interaction, reflected in the persistent attempts of the parasite to survive bivalve reaction. We have evidenced that both organisms trigger specific host reaction that although not costly in terms of host reproductive cycle or growth, results in mild tissue destruction and hemocyte activation. A lower degree of tissue reaction was observed in cases of hydroid infestation, compared to Turbellarian.
A. I. Golubev - One of the best experts on this subject based on the ideXlab platform.
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ULTRASTRUCTURE OF PARENCHYMA IN THE SYNCYTIAL DIGESTIVE SYSTEM IN Turbellaria Convoluta convoluta (Acoela
Morfologii︠a︡ (Saint Petersburg Russia), 2020Co-Authors: G. R. Gazizova, Ya. I. Zabotin, A. I. GolubevAbstract:The paper presents data on the ultrastructure of parenchyma that is involved in the digestion in Turbellaria Convoluta convoluta (n = 15). Unusual connections between the nuclear envelope, endoplasmic reticulum and plasma membrane of parenchymal cells were found for the first time, which may indicate the origin of these cell structures. The double trophic role of zooxanthellae in the organism of Convoluta is described.
E A Burenina - One of the best experts on this subject based on the ideXlab platform.
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phosphohydrolases in Turbellaria phagocata sibirica
Journal of Evolutionary Biochemistry and Physiology, 2019Co-Authors: E A Burenina, Marianna I ZhukovskayaAbstract:Activity and properties of two phosphohydrolases, nucleoside diphosphatase (NDPase) and 5′-nucleotidase, were assayed in subcellular fractions of Turbellaria Phagocata sibirica Sabussov (Turbellaria, Planariidae). The highest activity of N D Pase was observed in microsomes while that of 5′-nucleotidase in mitochondria and cytosolic fractions (12 000 and 105 000 g). The correlation between the rates of the relevant enzymatic reactions and concentrations of substrates and metal ions as well as the impact of various effectors and divalent cations (Mg2+, Mn2+, Ca2+, Zn2+, Cu2+) on phosphohydrolase activities were studied.
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Activity and properties of fructose bisphosphatase of Turbellaria Phagocata sibirica
Journal of Evolutionary Biochemistry and Physiology, 2011Co-Authors: E A BureninaAbstract:Activity and properties of fructose bisphosphatase (FBPase) were studied in the free-living Turbellarian Phagocata sibirica . All subcellular fractions of P. sibirica (12 000 g cytosol, 105 000 g cytosol, mitochondria, and microsomes) have the FBPase activity. Dependence of the FBPase reaction rate on the substrate concentration was studied. For realization of the enzyme activity, the high affinity to substrate and the presence of bivalent cations (Mg^2+ or Mn^2+) are necessary. There was studied the effect of various effectors as well as of monovalent (Na^+, K^+, Li^+, and NH^+) and bivalent (Zn^2+ and Cu^2+) cations.
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Activities and properties of phosphorylases of Turbellarias Phagocata sibirica and cestodes Bothriocephalus scorpii
Journal of Evolutionary Biochemistry and Physiology, 2007Co-Authors: E A BureninaAbstract:Activities and properties of phosphorylases of cytosol and mitochondrial fractions are studied in free-living Turbellarias Phagocata sibirica and cestodes Bothriocephalus scorpii. The phosphorylase activities in P. sibirica and B. scorpii differ significantly both in form and in total activity of this enzyme. Dependence of the phosphorylase reaction rate on substrate concentration is studied. The high activity of phosphorylase as compared with that of hexokinase suggests glycogen to be the main energy source of the studied flatworms. Action of various effectors on activities of the cytosol and mitochondrial phosphorylases has been studied.
Kornakova Ee - One of the best experts on this subject based on the ideXlab platform.
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Ultrastructural and morphological peculiarities of Turbellariae Bothrioplana semperi and the problem of monophilia of Seriata (Platyhelmimthes, Turbellaria)
Journal of Evolutionary Biochemistry and Physiology, 2012Co-Authors: Kornakova EeAbstract:The ultrastructure and morphogenesis of rhabdites as well as the morphology of pharynx walls in Bothrioplana semperi (Turbellaria, Bothrioplanidae) are described. The ultrastructure of rhabdites and their morphogenesis in this species are close to those in Macrostomida (Turbellaria Archoophora). The order of muscle layers in the pharynx walls of Bothrioplana semperi makes it similar to Tricladida Maricola and some Tricladida Paludicola and Terricola. The analysis of ultrastructural and morphological characters in Bothrioplana semperi as compared to those in Turbellaria Proseriata and Tricladida is provided. It is shown that relation of apomorphic and plesiomorphic characters in the phyla analyzed corresponds the most to the viewpoint about the early divergence of these groups from early Turbellaria Neoophora. In this case Proseriata and Tricladida are not sister groups, while Bothrioplanidae should be regarded as a sister group to the ancestors of Tricladida and, possibly, Neodermata.
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Peculiarities of ultrastructure of excretory system in Bothrioplana semperi (Platyhelminthes, Turbellaria)
Journal of Evolutionary Biochemistry and Physiology, 2010Co-Authors: Kornakova EeAbstract:Ultrastructural study of morphology of cirtocytes and excretory channels was performed in the free living Turbellaria Bothrioplana semperi (Turbellaria, Seriata). It has been shown that cirtocytes of this species are formed by two cells--the terminal and the proximal cells of the channel. The fan is composed of two rod rows. The external row goes out from the terminal cell, the internal one is a derivate of the channel proximal cell. Inside each rod of the external row there runs a bundle of microfilaments; it originates in the cytoplasm of the channel proximal cell distal to bases of the external rods. On the internal rod membranes there are noted small electrondense granules disposed separately or fused in the solid layer continuing into a dense "membrane" connecting rods of the external and internal rows. Rare internal leptotrichiae go out from the cirtocyte cavity bottom. External leptotrichiae are absent. The septate desmosome at the level of the terminal cell is absent, but is present in the channel proximal cell at the level of terminal of cilia. The apical surface of the channel cell carries rare short microvilli. The basement membrane of cells of excretory channels forms deep invaginations almost reaching the apical membrane. Epithelium of excretory channels is deprived of cilia. Ultrastructure of cirtocytes and excretory channels of B. semperi is similar to those in representatives of the suborder Proseriata (Seriata). The significance of ultrastructure of the Proseriata cirtocytes, especially of the order of formation of versh, for construction of phylogeny of Platyhelminthes is discussed.
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Structure of the epithelium of the parasitic Turbellaria Notenera ivanovi (Turbellaria: Fecampiida)
Parazitologiia, 2000Co-Authors: Kornakova Ee, Marchenkov AvAbstract:The ultrastructure of the epithelium in Notentera ivanovi (Turbellaria, Fecampiida) has been studied. Notentera ivanovi lacks the digestive system but has a pad of the epidermal cells on the dorsal side of the body, which seems to be similar to the digestive epidermis on LM. Both the ventral and dorsal epithelium are cellular, ciliated and not insunk (fig. 1, a). The ultrastructure of the ventral and dorsal epithelium is similar in essential features. The cells bear abundant microvilli, cilia and are very rich in mitochondria, but the cytoplasm does not contain lysosomes and shows no other indications of phago- or pinocytosis. The basal membrane of epithelial cells forms deep invaginations (fig. 1, [symbol: see text]), partly with dilations (fig. 1, a; 2, a) containing the lamellated material (3, [symbol: see text]). In the basal part of the cells the numerous Golgi apparatus and rare cysternae of the smooth endoplasmic reticulum were observed (fig. 2, a, [symbol: see text]). The epithelium consists of several types of cells, which differ in the structure of secretory granules. The most abundant type of cells contains the granules with the rough-fibrillated content (fig. 1, a; 2, [symbol: see text]; 3, a). The cells of this type cover most part of the body. In some cells the content of such granules becomes condensed and electron-dense granules appear (fig. 3, a, [symbol: see text]). Another type of cells contains the giant granules with the rough-fibrillated content (fig. 3, [symbol: see text]). Third type of the secret is the granules with the finely fibrillated content which is ejected by exocytosis. The cells of the second and third types form a separate areas of the epithelium of the dorsal side of the body but occasionally were observed in the ventral epithelium too. The epithelium of N. ivanovi differs from that in Kronborgia by the abundance and diversity of secretory contents. The role of the epithelium in the digestion remains conjectural. It seems to be mainly the suckering tissue transporting the low molecular nutrients.
