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Jiří Vávra - One of the best experts on this subject based on the ideXlab platform.
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establishment of a new microsporidian genus and species pseudoberwaldia Daphniae microsporidia opisthosporidia a common parasite of the Daphnia longispina complex in europe
Journal of Invertebrate Pathology, 2019Co-Authors: Jiří Vávra, Adam Petrusek, Ivan Fiala, Pavla Krylova, Miroslav HylisAbstract:Abstract Microsporidia are among the most common microparasites of cladocerans and have potentially significant impact on host populations. However, many of these pathogens are known only from molecular-based studies. We provide ultrastructural data supported by molecular phylogeny for a common microsporidium infecting the Daphnia longispina complex, important planktonic filter-feeders in reservoirs and ponds in the temperate Holarctic region. This parasite, previously characterized only by molecular means, infects adipose cells around the Daphnia midgut and eventually fills the centre of the host body with ovoid-shaped spores. A new microsporidian genus and species belonging to the Agglomeratidae superclade is described as Pseudoberwaldia Daphniae gen. et sp. nov. Molecular data indicate its widespread presence in Central European reservoirs (reported as isolate “MIC1”) but also in Swedish coastal rockpools (“Angskars-klubben”). The most closely related lineage was reported from a caddisfly larva; we thus speculate that this taxon may have an insect secondary host in its life cycle. Morphological characterization and differential diagnosis of most commonly encountered microsporidian taxa infecting hosts in the D. longispina complex in Europe opens new possibilities for studies of their ecological and evolutionary interactions.
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Occurrence, pathology, and ultrastructure of iridovirus and cytoplasmic polyhedrosis viruses in daphnids from the Czech Republic
Journal of Invertebrate Pathology, 2016Co-Authors: Jiří Vávra, Tomáš Bílý, Jana Nebesařova, Brian A. FedericiAbstract:Abstract Iridescent (IVs, family Iridoviridae, genus Iridovirus) and cytoplasmic polyhedrosis viruses (CPVs; family Reoviridae, genus Cypovirus) are well known in insects, with thirteen IV species recognized from various orders, and sixteen CPV species known from lepidopterans. In 1975, an IV and CPV were reported in the daphnid, Simocehpalus expinosus, in Florida, but other reported daphnid virus infections seem to be rare. Here we report infected daphnids from woodland and carp ponds in the Czech Republic, Daphnia curvirostris with an IV, and D. pulex and D. ambigua, with CPVs. This suggests these viruses are more common in daphnids, the rarity of reports due to few surveys.
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morphology molecular phylogeny and ecology of binucleata Daphniae n g n sp fungi microsporidia a parasite of Daphnia magna straus 1820 crustacea branchiopoda
Journal of Eukaryotic Microbiology, 2008Co-Authors: Dominik Refardt, Jiří Vávra, Ellen Decaestecker, Pieter T J JohnsonAbstract:We describe a new microsporidian species Binucleata Daphniae, n. g., n. sp., that infects the integument cells lining the hemocoele cavity of the carapace and the postabdomen of the cladoceran Daphnia magna Straus. Infected cells filled with spores accumulate as large clusters in the carapace cavity and heavily infected hosts are detected by their opaque appearance. Despite the parasite's presence, infected Daphnia grow and molt, but have a reduced fecundity. During the parasite's life cycle, chain-like meronts with isolated nuclei are formed, giving rise to binucleate presporonts, the most frequently observed, characteristic developmental stage. In sporogony, the nuclei of the presporont separate, divide, and eight spores enclosed in a thin-walled sporophorous vesicle are formed. Spores are 4.9 x 2.5 microm in size (fresh) and have an anisofilar polar filament with eight coils. DNA sequence analysis places B. Daphniae in a clade of microsporidians that parasitize crustaceans and mosquitoes and have assumed complex life cycles. Binucleata Daphniae, however, has a simple and direct life cycle and can be transferred to naive hosts and maintained as persistent infections in populations of its host D. magna. We propose that B. Daphniae has simplified its life cycle by losing its secondary host, rendering it unique in this clade.
Lars-henrik Heckmann - One of the best experts on this subject based on the ideXlab platform.
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outlining eicosanoid biosynthesis in the crustacean Daphnia
Frontiers in Zoology, 2008Co-Authors: Lars-henrik Heckmann, Martijn J T N Timmermans, Richard M. Sibly, Amanda CallaghanAbstract:Background: Eicosanoids are biologically active, oxygenated metabolites of three C20 polyunsaturated fatty acids. They act as signalling molecules within the autocrine or paracrine system in both vertebrates and invertebrates mainly functioning as important mediators in reproduction, the immune system and ion transport. The biosynthesis of eicosanoids has been intensively studied in mammals and it is known that they are synthesised from the fatty acid, arachidonic acid, through either the cyclooxygenase (COX) pathway; the lipoxygenase (LOX) pathway; or the cytochrome P450 epoxygenase pathway. However, little is still known about the synthesis and structure of the pathway in invertebrates. Results: Here, we show transcriptomic evidence from Daphnia magna (Crustacea: Branchiopoda) together with a bioinformatic analysis of the D. pulex genome providing insight on the role of eicosanoids in these crustaceans as well as outlining a putative pathway of eicosanoid biosynthesis. Daphnia appear only to have one copy of the gene encoding the key enzyme COX, and phylogenetic analysis reveals that the predicted protein sequence of Daphnia COX clusters with other invertebrates. There is no current evidence of an epoxygenase pathway in Daphnia; however, LOX products are most certainly synthesised in daphnids. Conclusion: We have outlined the structure of eicosanoid biosynthesis in Daphnia, a key genus in freshwater ecosystems. Improved knowledge of the function and synthesis of eicosanoids in Daphnia and other invertebrates could have important implications for several areas within ecology. This provisional overview of daphnid eicosanoid biosynthesis provides a guide on where to focus future research activities in this area.
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outlining eicosanoid biosynthesis in the crustacean Daphnia
Frontiers in Zoology, 2008Co-Authors: Lars-henrik Heckmann, Martijn J T N Timmermans, Richard M. Sibly, Amanda CallaghanAbstract:Background: Eicosanoids are biologically active, oxygenated metabolites of three C20 polyunsaturated fatty acids. They act as signalling molecules within the autocrine or paracrine system in both vertebrates and invertebrates mainly functioning as important mediators in reproduction, the immune system and ion transport. The biosynthesis of eicosanoids has been intensively studied in mammals and it is known that they are synthesised from the fatty acid, arachidonic acid, through either the cyclooxygenase (COX) pathway; the lipoxygenase (LOX) pathway; or the cytochrome P450 epoxygenase pathway. However, little is still known about the synthesis and structure of the pathway in invertebrates. Results: Here, we show transcriptomic evidence from Daphnia magna (Crustacea: Branchiopoda) together with a bioinformatic analysis of the D. pulex genome providing insight on the role of eicosanoids in these crustaceans as well as outlining a putative pathway of eicosanoid biosynthesis. Daphnia appear only to have one copy of the gene encoding the key enzyme COX, and phylogenetic analysis reveals that the predicted protein sequence of Daphnia COX clusters with other invertebrates. There is no current evidence of an epoxygenase pathway in Daphnia; however, LOX products are most certainly synthesised in daphnids. Conclusion: We have outlined the structure of eicosanoid biosynthesis in Daphnia, a key genus in freshwater ecosystems. Improved knowledge of the function and synthesis of eicosanoids in Daphnia and other invertebrates could have important implications for several areas within ecology. This provisional overview of daphnid eicosanoid biosynthesis provides a guide on where to focus future research activities in this area.
Amanda Callaghan - One of the best experts on this subject based on the ideXlab platform.
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outlining eicosanoid biosynthesis in the crustacean Daphnia
Frontiers in Zoology, 2008Co-Authors: Lars-henrik Heckmann, Martijn J T N Timmermans, Richard M. Sibly, Amanda CallaghanAbstract:Background: Eicosanoids are biologically active, oxygenated metabolites of three C20 polyunsaturated fatty acids. They act as signalling molecules within the autocrine or paracrine system in both vertebrates and invertebrates mainly functioning as important mediators in reproduction, the immune system and ion transport. The biosynthesis of eicosanoids has been intensively studied in mammals and it is known that they are synthesised from the fatty acid, arachidonic acid, through either the cyclooxygenase (COX) pathway; the lipoxygenase (LOX) pathway; or the cytochrome P450 epoxygenase pathway. However, little is still known about the synthesis and structure of the pathway in invertebrates. Results: Here, we show transcriptomic evidence from Daphnia magna (Crustacea: Branchiopoda) together with a bioinformatic analysis of the D. pulex genome providing insight on the role of eicosanoids in these crustaceans as well as outlining a putative pathway of eicosanoid biosynthesis. Daphnia appear only to have one copy of the gene encoding the key enzyme COX, and phylogenetic analysis reveals that the predicted protein sequence of Daphnia COX clusters with other invertebrates. There is no current evidence of an epoxygenase pathway in Daphnia; however, LOX products are most certainly synthesised in daphnids. Conclusion: We have outlined the structure of eicosanoid biosynthesis in Daphnia, a key genus in freshwater ecosystems. Improved knowledge of the function and synthesis of eicosanoids in Daphnia and other invertebrates could have important implications for several areas within ecology. This provisional overview of daphnid eicosanoid biosynthesis provides a guide on where to focus future research activities in this area.
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outlining eicosanoid biosynthesis in the crustacean Daphnia
Frontiers in Zoology, 2008Co-Authors: Lars-henrik Heckmann, Martijn J T N Timmermans, Richard M. Sibly, Amanda CallaghanAbstract:Background: Eicosanoids are biologically active, oxygenated metabolites of three C20 polyunsaturated fatty acids. They act as signalling molecules within the autocrine or paracrine system in both vertebrates and invertebrates mainly functioning as important mediators in reproduction, the immune system and ion transport. The biosynthesis of eicosanoids has been intensively studied in mammals and it is known that they are synthesised from the fatty acid, arachidonic acid, through either the cyclooxygenase (COX) pathway; the lipoxygenase (LOX) pathway; or the cytochrome P450 epoxygenase pathway. However, little is still known about the synthesis and structure of the pathway in invertebrates. Results: Here, we show transcriptomic evidence from Daphnia magna (Crustacea: Branchiopoda) together with a bioinformatic analysis of the D. pulex genome providing insight on the role of eicosanoids in these crustaceans as well as outlining a putative pathway of eicosanoid biosynthesis. Daphnia appear only to have one copy of the gene encoding the key enzyme COX, and phylogenetic analysis reveals that the predicted protein sequence of Daphnia COX clusters with other invertebrates. There is no current evidence of an epoxygenase pathway in Daphnia; however, LOX products are most certainly synthesised in daphnids. Conclusion: We have outlined the structure of eicosanoid biosynthesis in Daphnia, a key genus in freshwater ecosystems. Improved knowledge of the function and synthesis of eicosanoids in Daphnia and other invertebrates could have important implications for several areas within ecology. This provisional overview of daphnid eicosanoid biosynthesis provides a guide on where to focus future research activities in this area.
Hajime Watanabe - One of the best experts on this subject based on the ideXlab platform.
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betaproteobacteria limnohabitans strains increase fecundity in the crustacean Daphnia magna symbiotic relationship between major bacterioplankton and zooplankton in freshwater ecosystem
Environmental Microbiology, 2016Co-Authors: Saranya Peerakietkhajorn, Tomoaki Matsuura, Vojtěch Kasalický, Yasuhiko Kato, Hajime WatanabeAbstract:Summary How symbioses between bacteria and aquatic animals influence food webs in freshwater ecosystems is a fundamental question in ecology. We investigated symbiosis between a crustacean zooplankton Daphnia magna and its dominant bacterial symbiont Limnohabitans, an abundant and globally distributed freshwater Betaproteobacteria. Aposymbiotic juvenile Daphnia were prepared and exposed to any of four Limnohabitans sp. – Limnohabitans strains DM1, 2KL-3, 2KL-7 and Limnohabitans planktonicus strain II-D5, all previously found in D. magna digestive tract or culture. Re-infected Daphnia were cultured until they produced the first clutch of juveniles. Limnohabitans strain DM1 and L. planktonicus strain II-D5 successfully re-infected Daphnia through single exposure at the first instar juvenile stage. In contrast to aposymbiotic Daphnia that produced non-viable juveniles, re-infected Daphnia produced viable juveniles and increased fecundity to levels of that of symbiotic Daphnia. Re-infected Daphnia did not increase their number of eggs nor growth rates. Limnohabitans strains 2KL-7 and 2KL-3 could not recover fecundity even in multiple exposures during culture. This study shows the functional evidence demonstrating that a single bacterium Limnohabitans regulates fecundity of the consumer Daphnia through symbiosis. Our results indicated that symbiotic relationship between major bacterioplankton and zooplankton is important for maintaining the population of zooplankton in freshwater ecosystems.
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growth evaluation method by live imaging of Daphnia magna and its application to the estimation of an insect growth regulator
Journal of Applied Toxicology, 2015Co-Authors: Akiko Suzuki, Tomoaki Matsuura, Yasuhiko Kato, Hajime WatanabeAbstract:The zooplankton Daphnia magna has been widely used as a test organism to assess the toxicity of chemical substances because of its important position in aquatic ecology and its ease of handling. Among the various endpoints for toxicity evaluation, growth rate is one of the most critical and many studies have been conducted. However, measurement of growth rate was time-consuming and not an ideal endpoint in terms of screening. In this study, we demonstrated a live imaging method to monitor the growth of daphnids by area measurement. In this method, daphnid images were directly obtained from a swimming chamber and these images were processed for the evaluation of growth. The reliability of this method was confirmed by comparison with the conventional dry weight method of the same animals. The body area of daphnids using this method showed a strong correlation with the dry weight method, with R2 = 0.930. In addition, we quantified the effect of a toxicant, fenoxycarb, on the growth of the animal. Fenoxycarb concentrations of 0, 0.027, 0.27 and 2.7 µg l–1 were tested and their effects on growth were estimated by the live imaging method. In the toxicity test, the area of daphnids decreased significantly with increasing fenoxycarb concentration. These results indicate that the present live imaging method is a reliable approach for daphnid toxicity testing. This method is promising for high-throughput Daphnia toxicity tests and real-time individual observations. Copyright © 2014 John Wiley & Sons, Ltd.
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Analysis of expressed sequence tags of the water flea Daphnia magna
Genome, 2005Co-Authors: Hajime Watanabe, Norihisa Tatarazako, Shigeto Oda, Hiroyo Nishide, Ikuo Uchiyama, Masatoshi Morita, Taisen IguchiAbstract:To study gene expression in the water flea Daphnia magna we constructed a cDNA library and characterized the expressed sequence tags (ESTs) of 7210 clones. The EST sequences clustered into 2958 nonredundant groups. BLAST analyses of both protein and DNA databases showed that 1218 (41%) of the unique sequences shared significant similarities to known nucleotide or amino acid sequences, whereas the remaining 1740 (59%) showed no significant similarities to other genes. Clustering analysis revealed particularly high expression of genes related to ATP synthesis, structural proteins, and proteases. The cDNA clones and EST sequence information should be useful for future functional analysis of daphnid biology and investigation of the links between ecology and genomics.Key words: Daphnia magna, EST, classification, ATP synthesis.
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analysis of expressed sequence tags of the water flea Daphnia magna
Genome, 2005Co-Authors: Hajime Watanabe, Norihisa Tatarazako, Shigeto Oda, Hiroyo Nishide, Ikuo Uchiyama, Masatoshi Morita, Taisen IguchiAbstract:To study gene expression in the water flea Daphnia magna we constructed a cDNA library and characterized the expressed sequence tags (ESTs) of 7210 clones. The EST sequences clustered into 2958 nonredundant groups. BLAST analyses of both protein and DNA databases showed that 1218 (41%) of the unique sequences shared significant similarities to known nucleotide or amino acid sequences, whereas the remaining 1740 (59%) showed no significant similarities to other genes. Clustering analysis revealed particularly high expression of genes related to ATP synthesis, structural proteins, and proteases. The cDNA clones and EST sequence information should be useful for future functional analysis of daphnid biology and investigation of the links between ecology and genomics.
Ridha Saputri - One of the best experts on this subject based on the ideXlab platform.
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pengaruh pemberian Daphnia sp diperkaya dengan viterna terhadap pertumbuhan dan kelangsungan hidup benih ikan depik rasbora tawarensis
Jurnal Ilmiah Mahasiswa Kelautan Perikanan Unsyiah, 2019Co-Authors: Ridha Saputri, Iwan Hasri, Irma Dewiyanti, Nurfadillah Nurfadillah, Siska MelissaAbstract:ABSTRAK Ikan Depik ( Rasbora tawarensis ) merupakan salah satu ikan endemik yang tersebar luas dan dominan tertangkap di Danau Laut Tawar (DLT), Aceh Tengah. Tujuan penelitian ini untuk menganalisa pengaruh pemberian Daphnia sp. yang diperkaya viterna dengan dosis berbeda terhadap kelangsungan hidup dan pertumbuhan benih ikan depik. Penelitian ini dilakukan di BBI Lukup Badak, Aceh Tengah dari Juli - Agustus 2018. Metode yang digunakan adalah Rancangan Acak Lengkap (RAL) dengan 5 perlakuan dan 3 kali ulangan yaitu A (kontrol), B ( Daphnia sp. diperkaya viterna 10 ml/L), C ( Daphnia sp . diperkaya viterna 20 ml/L), D ( Daphnia sp. diperkaya viterna 30 ml/L) dan E ( Daphnia sp. diperkaya viterna 40 ml /L). Ikan diberi pakan 2 kali sehari secara ad-libitum . Hasil uji ANOVA menunjukkan bahwa Daphnia sp . yang diperkaya dengan viterna dosis berbeda berpengaruh nyata terhadap kelangsungan hidup, pertumbuhan panjang mutlak, pertumbuhan bobot mutlak, serta laju pertumbuhan spesifik benih ikan depik (P<0,05). Hasil penelitian ini memperlihatkan nilai tertinggi terdapat pada perlakuan D dengan kelangsungan hidup (88,89%), pertumbuhan panjang mutlak (0,70 cm), pertumbuhan bobot mutlak (0,36 gr) dan laju pertumbuhan spesifik (0,66%/ hari). Kata kunci : Daphnia sp , Kelangsungan hidup, Laju pertumbuhan, Rasbora tawarensis, Viterna ABSTRACT Depik ( Rasbora tawarensis ) is one of the endemic fish that is widespread and dominantly caught on Danau Laut Tawar (DLT), Aceh Tengah. The objective of this study was to determine the effect of Daphnia sp . enriched by viterna with the different dosage on the survival rate and growth rate of Depik. This research was conducted at technical implementation unit of fish breeding center Lukup Badak, Pegasing district, Aceh Tengah on July - August 2018. The method used which were Completely Randomized Design (CRD) with 5 level of treatments and three replications namely a, A (control), B ( Daphnia sp. enriched viterna 10 ml/L), C ( Daphnia sp . enriched viterna 20 ml/L), D ( Daphnia sp. enriched by 30 ml/L) and E ( Daphnia sp. enriched viterna 40 ml/L). Fish was fed three times a day with ad-libitum method. The result of BNT showed that Daphnia sp . enriched by the different dosage of viterna gave the effect on the survival rate, absolute length growth, absolute weight growth and specific growth rate of Depik (P<0.05). The optimum value for those parameters were obtained at treatment D, the absolute length growth was 0.70 cm, absolute weight growth was 0.36 g, specific growth rate was 0.66 % / day and survival rate was 88.89 %. Keywords: Daphnia sp., growth rate, viterna , survival rate, Rasbora tawarensis
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PENGARUH PEMBERIAN Daphnia SP. DIPERKAYA DENGAN VITERNA TERHADAP PERTUMBUHAN DAN KELANGSUNGAN HIDUP BENIH IKAN DEPIK (RASBORA TAWARENSIS)
FAKULTAS KELAUTAN DAN PERIKANAN UNIVERSITAS SYIAH KUALA, 2019Co-Authors: Ridha SaputriAbstract:ABSTRAKIkan Depik (Rasbora tawarensis) merupakan salah satu ikan endemik yang hanya tersebar luas dan dominan tertangkap di Danau Laut Tawar (DLT), Aceh Tengah. Tujuan penelitian ini untuk mengetahui pengaruh pemberian Daphnia sp. yang diperkaya viterna dengan dosis berbeda terhadap kelangsungan hidup dan pertumbuhan benih ikan depik. Penelitian ini dilakukan di BBI Lukup Badak, Aceh Tengah dari Juli - Agustus 2018. Metode yang digunakan adalah Rancangan Acak Lengkap (RAL) dengan 5 perlakuan dan 3 kali ulangan yaitu A (kontrol), B (Daphnia sp. diperkaya viterna 10 ml/L), C (Daphnia sp. diperkaya viterna 20 ml/L), D (Daphnia sp.diperkaya viterna 30 ml/L) dan E (Daphnia sp. diperkaya viterna 40 ml/L). Ikan diberi pakan 2 kali sehari secara ad-libitum. Hasil uji BNT menunjukkan bahwa Daphnia sp. yang diperkaya dengan viterna dosis berbeda berpengaruh nyata terhadap kelangsungan hidup, pertumbuhan panjang mutlak, pertumbuhan bobot mutlak, serta laju pertumbuhan spesifik benih ikan depik (Rasbora tawarensis) (PBanda Ace
