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Molecular Genetic Studies on Myxobolus cylindricus and Henneguya mystasi (Myxosporea: Myxobolidae) Infecting Two Indian Fish Species, Channa gachua and Mystus vittatus, Respectively. Acta Parasitol 2019; 64:129-137. [PMID: 30637559 DOI: 10.2478/s11686-018-00014-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 11/29/2018] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Myxozoan infections of Indian freshwater fishes are relatively well studied, but their validity is supported with molecular and phylogenetic data only for a few species. OBJECTIVES The primary objective was to present molecular data for two Myxozoan species, Myxobolus cylindricus and Henneguya gachua collected from Indian freshwater fishes, the dwarf snakehead Channa gachua and the striped dwarf catfish Mystus vittatus, respectively. METHODS Various organs of 56 C. gachua and 48 M. vittatus were dissected. Myxozoan plasmodia with mature spores were collected from the gills under a dissecting microscope. Spores obtained from plasmodia from infected hosts were fixed in 80% ethanol in vials and sent for further morphological and molecular examinations to Hungary. The 18S rDNA gene of Myxobolus and Henneguya spp. was amplified using nested polymerase chain reaction (PCR). Phylogenetic analysis was performed using maximum likelihood (ML) and Bayesian inference (BI) methods. RESULTS Morphological characteristics of M. cylindricus and H. mystasi spores corresponded to the original descriptions made by Sarkar, Mazumdar and Pramanik, 1985 and Haldar, Samal, and Mukhopadhyay, 1997, respectively. Phylogenetic analysis of the 18S rDNA gene revealed that the sequences of M. cylindricus differed from those of most Indian Myxobolus sp., known mostly from cyprinid fishes and formed a subgroup with Myxobolus neurophilus, a parasite of a perciform host, and with Henneguya chaudhuryi, a species belonging to a different genus but described from a closely related channid host. It was also closely related to another Henneguya species, H. lesteri, described from Sillago analis, a coastal fish. Henneguya mystasi had the closest similarity to Henneguya bicaudi, a species described from an Indian cyprinid fish and to Henneguya pellucida reported from a characid fish known from South America. CONCLUSION Molecular data received by us gives a solid basis for further identification of these myxozoans, the pathogenicity of which probably plays an economic role at culturing the hosts.
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Rangel LF, Rocha S, Casal G, Castro R, Severino R, Azevedo C, Cavaleiro F, Santos MJ. Life cycle inference and phylogeny of Ortholinea labracis n. sp. (Myxosporea: Ortholineidae), a parasite of the European seabass Dicentrarchus labrax (Teleostei: Moronidae), in a Portuguese fish farm. JOURNAL OF FISH DISEASES 2017; 40:243-262. [PMID: 27307300 DOI: 10.1111/jfd.12508] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 04/22/2016] [Accepted: 04/25/2016] [Indexed: 06/06/2023]
Abstract
Ortholinea labracis n. sp. is described and its life cycle is inferred from a Southern Portuguese fish farm, with basis on microscopic and molecular procedures. This myxosporean parasite infects the urinary bladder of the European seabass Dicentrarchus labrax and the intestinal epithelium of a marine oligochaete of the genus Tectidrilus. Myxospores subspherical in valvular view and ellipsoidal in sutural view measuring 7.6 ± 0.3 (6.8-8.7) μm in length, 7.2 ± 0.2 (6.7-7.7) μm in width and 6.5 ± 0.4 (5.8-7.7) μm in thickness. Two polar capsules, 3.0 ± 0.2 (2.6-3.4) μm long and 2.4 ± 0.1 (2.0-2.9) μm wide, located at the same level, but with divergent orientation and opening to opposite sides of the suture line. Sequencing of the SSU rRNA gene revealed a similarity of 100% between the analysed myxospores and triactinomyxon actinospores. The phylogenetic setting of O. labracis n. sp. shows subgrouping in correlation with tissue tropism, but identifies this parasite as another exception to the main division of Myxosporea into the main freshwater and marine lineages.
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Affiliation(s)
- L F Rangel
- Laboratory of Animal Pathology, Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
| | - S Rocha
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
- Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - G Casal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
- Department of Sciences, University Institute of Health Sciences, CESPU, Gandra, Portugal
| | - R Castro
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
| | - R Severino
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
| | - C Azevedo
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
- Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- Zoology Department, College of Sciences, King Saud University, Riyadh, Saudi Arabia
| | - F Cavaleiro
- Laboratory of Animal Pathology, Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
| | - M J Santos
- Laboratory of Animal Pathology, Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
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Rangel LF, Rocha S, Castro R, Severino R, Casal G, Azevedo C, Cavaleiro F, Santos MJ. The life cycle of Ortholinea auratae (Myxozoa: Ortholineidae) involves an actinospore of the triactinomyxon morphotype infecting a marine oligochaete. Parasitol Res 2015; 114:2671-8. [DOI: 10.1007/s00436-015-4472-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 04/07/2015] [Indexed: 12/01/2022]
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Tossavi ND, Gbankoto A, Yessoufou A, Escande ML, Dimitri G, Ribou AC, Moutaïrou K, Sakiti GN. Histopathological and ultrastructural studies of a Henneguya species (Myxozoa: Myxosporea) infesting the intestine of Clarias gariepinus from Benin (West Africa). Parasitol Res 2014; 114:861-72. [PMID: 25538022 DOI: 10.1007/s00436-014-4249-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 11/26/2014] [Indexed: 11/30/2022]
Abstract
Fish culture is the best alternative to fill the gap between natural fish catches and estimated needs of populations in animal protein consumption. In West Africa, this goal required to have suitable fishes for aquaculture which are Clariidae and Tilapia. Clarias gariepinus (Clariidae) fetches a higher price than tilapias as it can be sold alive at the market but a high infestation by Henneguya leads to decrease this commercial value. Those reasons lead us to perform studies on seasonal variations, histopathological aspects and life cycle of Henneguya sp. infecting the intestine of C. gariepinus using light and electron microscope. From November 2011 to December 2012, 339 specimens were collected from Ouémé River (Benin) and examined. An overall prevalence of 7.37 % was recorded for plasmodia of Henneguya sp. Parasite occurrence did not vary significantly between seasons (χ(2) = 12.235; df = 3; p > 0.05), nor sexes (χ(2) = 2.992; df = 7; p > 0.05) while differences were significant between classes of weight (χ(2) = 39.929; df = 5; p < 0.05). The highest prevalence was recorded in host ranging from 300 to 374 g. Histopathological analysis showed that the mass continuous development of the plasmodium produced thickening of the intestine wall and compressed neighboring tissues and destroyed villi and smooth muscle layers. The stages of the parasite development including sporogenesis, capsulogenesis, and valvogenesis were asynchronous. Investigations are still running by molecular approaches in order to identify accurately this species.
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Affiliation(s)
- Nounagnon Darius Tossavi
- Département de Zoologie, Faculté des Sciences et Techniques, Université d'Abomey-Calavi, 01 BP 526, Cotonou, Bénin,
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Shpirer E, Chang ES, Diamant A, Rubinstein N, Cartwright P, Huchon D. Diversity and evolution of myxozoan minicollagens and nematogalectins. BMC Evol Biol 2014; 14:205. [PMID: 25262812 PMCID: PMC4195985 DOI: 10.1186/s12862-014-0205-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 09/19/2014] [Indexed: 11/10/2022] Open
Abstract
Background Myxozoa are a diverse group of metazoan parasites with a very simple organization, which has for decades eluded their evolutionary origin. Their most prominent and characteristic feature is the polar capsule: a complex intracellular structure of the myxozoan spore, which plays a role in host infection. Striking morphological similarities have been found between myxozoan polar capsules and nematocysts, the stinging structures of cnidarians (corals, sea anemones and jellyfish) leading to the suggestion that Myxozoa and Cnidaria share a more recent common ancestry. This hypothesis has recently been supported by phylogenomic evidence and by the identification of a nematocyst specific minicollagen gene in the myxozoan Tetracapsuloides bryosalmonae. Here we searched genomes and transcriptomes of several myxozoan taxa for the presence of additional cnidarian specific genes and characterized these genes within a phylogenetic context. Results Illumina assemblies of transcriptome or genome data of three myxozoan species (Enteromyxum leei, Kudoa iwatai, and Sphaeromyxa zaharoni) and of the enigmatic cnidarian parasite Polypodium hydriforme (Polypodiozoa) were mined using tBlastn searches with nematocyst-specific proteins as queries. Several orthologs of nematogalectins and minicollagens were identified. Our phylogenetic analyses indicate that myxozoans possess three distinct minicollagens. We found that the cnidarian repertoire of nematogalectins is more complex than previously thought and we identified additional members of the nematogalectin family. Cnidarians were found to possess four nematogalectin/ nematogalectin-related genes, while in myxozoans only three genes could be identified. Conclusions Our results demonstrate that myxozoans possess a diverse array of genes that are taxonomically restricted to Cnidaria. Characterization of these genes provide compelling evidence that polar capsules and nematocysts are homologous structures and that myxozoans are highly degenerate cnidarians. The diversity of minicollagens was higher than previously thought, with the presence of three minicollagen genes in myxozoans. Our phylogenetic results suggest that the different myxozoan sequences are the results of ancient divergences within Cnidaria and not of recent specializations of the polar capsule. For both minicollagen and nematogalectin, our results show that myxozoans possess less gene copies than their cnidarian counter parts, suggesting that the polar capsule gene repertoire was simplified with their reduced body plan. Electronic supplementary material The online version of this article (doi:10.1186/s12862-014-0205-0) contains supplementary material, which is available to authorized users.
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Carriero MM, Adriano EA, Silva MRM, Ceccarelli PS, Maia AAM. Molecular phylogeny of the Myxobolus and Henneguya genera with several new South American species. PLoS One 2013; 8:e73713. [PMID: 24040037 PMCID: PMC3764033 DOI: 10.1371/journal.pone.0073713] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 07/04/2013] [Indexed: 12/01/2022] Open
Abstract
The present study consists of a detailed phylogenetic analysis of myxosporeans of the Myxobolus and Henneguya genera, including sequences from 12 Myxobolus/Henneguya species, parasites of South American pimelodids, bryconids and characids. Maximum likelihood and maximum parsimony analyses, based on 18 S rDNA gene sequences, showed that the strongest evolutionary signal is the phylogenetic affinity of the fish hosts, with clustering mainly occurring according to the order and/or family of the host. Of the 12 South American species studied here, six are newly described infecting fish from the Brazilian Pantanal wetland. Henneguya maculosus n. sp. and Myxobolus flavus n. sp. were found infecting both Pseudoplatystoma corruscans and Pseudoplatystoma reticulatum; Myxobolus aureus n. sp. and Myxobolus pantanalis n. sp. were observed parasitizing Salminus brasiliensis and Myxobolus umidus n. sp. and Myxobolus piraputangae n. sp. were detected infecting Brycon hilarii.
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MESH Headings
- Animals
- Brazil
- DNA, Protozoan/chemistry
- DNA, Protozoan/genetics
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- Fish Diseases/parasitology
- Fishes/classification
- Fishes/parasitology
- Molecular Sequence Data
- Myxozoa/anatomy & histology
- Myxozoa/classification
- Myxozoa/genetics
- Parasitic Diseases, Animal/parasitology
- Phylogeny
- Polymerase Chain Reaction
- RNA, Ribosomal, 18S/classification
- RNA, Ribosomal, 18S/genetics
- Sequence Analysis, DNA
- Species Specificity
- Spores, Protozoan/cytology
- Spores, Protozoan/genetics
- Wetlands
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Affiliation(s)
- Mateus Maldonado Carriero
- Departamento de Medicina Veterinária, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Pirassununga, São Paulo, Brazil
| | - Edson A. Adriano
- Departamento de Ciências Biológicas, Universidade Federal de São Paulo, Diadema, São Paulo, Brazil
- Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
- * E-mail:
| | - Márcia R. M. Silva
- Departamento de Medicina Veterinária, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Pirassununga, São Paulo, Brazil
| | - Paulo S. Ceccarelli
- Centro Nacional de Pesquisa e Conservação de Peixes Continentais, Instituto Chico Mendes de Conservação da Biodiversidade, Pirassununga, São Paulo, Brazil
| | - Antonio A. M. Maia
- Departamento de Medicina Veterinária, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Pirassununga, São Paulo, Brazil
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Abstract
Global aquaculture production of turbot has rapidly increased worldwide in the last decade and it is expected to have even bigger growth in the next years due to new farms operating. The losses caused by pathogen infections have grown at the same time as the production of this species. Parasitological infections are among the main relevant pathologies associated with its culture and produce serious losses in aquaculture, reduce the growth rate in fish and may lead to unmarketable fish due to skeletal muscle abnormalities in cases with high intensity of infection. The microsporidian parasite Tetramicra brevifilum causes severe infections and generates major losses in farmed turbot. Infections are difficult to control due to spore longevity and its direct transmission. To facilitate the infection management, an effective tool for fast detection and identification of T. brevifilum is needed. This study provides a molecular methodology of fast Real-Time PCR for T. brevifilum detection to the aquaculture industry, useful for routine control of T. brevifilum at turbot farms. The method is characterized by its high specificity and sensitivity, and it can be applied to cultured turbot for parasite detection regardless of the life-cycle stage of the pathogen or the infection intensity.
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Morris DJ. A new model for myxosporean (Myxozoa) development explains the endogenous budding phenomenon, the nature of cell within cell life stages and evolution of parasitism from a cnidarian ancestor. Int J Parasitol 2012; 42:829-40. [PMID: 22749958 DOI: 10.1016/j.ijpara.2012.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 06/05/2012] [Accepted: 06/06/2012] [Indexed: 11/17/2022]
Abstract
The phylum Myxozoa is composed of endoparasitic species that have predominately been recorded within aquatic vertebrates. The simple body form of a trophic cell containing other cells within it, as observed within these hosts, has provided few clues to relationships with other organisms. In addition, the placement of the group using molecular phylogenies has proved very difficult, although the majority of analyses now suggest that they are cnidarians. There have been relatively few studies of myxozoan stages within invertebrate hosts, even though these exhibit multicellular and sexual stages that may provide clues to myxozoan evolution. Therefore an ultrastructural examination of a myxozoan infection of a freshwater oligochaete was conducted, to reassess and formulate a model for myxozoan development in these hosts. This deemed that meiosis occurs within the oligochaete, but that fertilisation is not immediate. Rather, the resultant haploid germ cell (oocyte) is engulfed by a diploid sporogonic cell (nurse cell) to form a sporoplasm. It is this sporoplasm that infects the fish, resulting in the multicellular stages observed. Fertilisation occurs after the parasites leave the fish and enter the oligochaete host. The nurse cell/oocyte model explains previously conflicting evidence in the literature regarding myxosporean biology, and aligns phenomena considered distinctive to the Myxozoa, such as endogenous budding and cell within cell development, with processes recorded in cnidarians. Finally, the evolutionary origin of the Myxozoa as cnidarian parasites of ova is hypothesised.
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Affiliation(s)
- D J Morris
- Institute of Aquaculture, University of Stirling, Stirling, Scotland, UK.
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Rangel LF, Azevedo C, Casal G, Santos MJ. Ultrastructural Aspects of Ellipsomyxa mugilis (Myxozoa: Ceratomyxidae) Spores and Developmental Stages In Nereis diversicolor (Polychaeta: Nereidae). J Parasitol 2012; 98:513-9. [DOI: 10.1645/ge-3005.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Liu Y, Whipps CM, Gu ZM, Zeng LB. Myxobolus turpisrotundus (Myxosporea: Bivalvulida) spores with caudal appendages: investigating the validity of the genus Henneguya with morphological and molecular evidence. Parasitol Res 2010; 107:699-706. [PMID: 20512504 DOI: 10.1007/s00436-010-1924-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Accepted: 05/12/2010] [Indexed: 10/19/2022]
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Abstract
Eukaryotes form new cells through the replication of nuclei followed by cytokinesis. A notable exception is reported from the class Myxosporea of the phylum Myxozoa. This assemblage of approximately 2310 species is regarded as either basal bilaterian or cnidarian, depending on the phylogenetic analysis employed. For myxosporeans, cells have long been regarded as forming within other cells by a process referred to as endogenous budding. This would involve a nucleus forming endoplasmic reticulum around it, which transforms into a new plasma membrane, thus enclosing and separating it from the surrounding cell. This remarkable process, unique within the Metazoa, is accepted as occurring within stages found in vertebrate hosts, but has only been inferred from those stages observed within invertebrate hosts. Therefore, I conducted an ultrastructural study to examine how internal cells are formed by a myxosporean parasitizing an annelid. In this case, actinospore parasite stages clearly internalized existing cells; a process with analogies to the acquisition of endosymbiotic algae by cnidarian species. A subsequent examination of the myxozoan literature did not support endogenous budding, indicating that this process, which has been a central tenet of myxozoan developmental biology for over a century, is dogma.
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Affiliation(s)
- David J Morris
- Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, UK.
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Morris D, Freeman M. Hyperparasitism has wide-ranging implications for studies on the invertebrate phase of myxosporean (Myxozoa) life cycles. Int J Parasitol 2010; 40:357-69. [DOI: 10.1016/j.ijpara.2009.08.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2009] [Revised: 08/27/2009] [Accepted: 08/29/2009] [Indexed: 11/25/2022]
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Hawke JP, Khoo LH. 14 Infectious diseases. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/s0167-9309(04)80016-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
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Oumouna M, Hallett SL, Hoffmann RW, El-Matbouli M. Early developmental stages of two actinosporeans, Raabeia and Aurantiactinomyxon (Myxozoa), as detected by light and electron microscopy. J Invertebr Pathol 2002; 79:17-26. [PMID: 12054783 DOI: 10.1016/s0022-2011(02)00007-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The development of actinosporeans in their oligochaete host proceeding pansporocyst formation is relatively well documented, however, phases preceding it are not as well known. The initial stages in the development of two actinosporeans, Raabeia type 1 of Oumouna et al. [Parasitol. Res. 2002] and Aurantiactinomyxon pavinsis (Ormières, 1968) Marquès [Languedoc, Universite des Sciences et Techniques, Dissertation, 1984] from schizogony to gametogony and sporogony are described. Both actinosporeans begin their development as multinucleate stages near the basal lamina of the oligochaete intestine. Proximal to these stages and between the host epithelium cells are uninucleate cells whose nuclei divide to produce binucleate cells. These divide mitotically to produce cells with four nuclei which then undergo plasmotomy to yield a tetracellular stage and the first phase in pansporocyst formation. From the uninucleate stage to the tetranucleate stage, the cell membrane of the parasite is associated closely via finger-like projections with the intestinal epithelial and glandular cells of the host.
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Affiliation(s)
- M Oumouna
- Institute for Zoology Fish Biology and Fish Diseases, Kaulbachstrasse 37, 80539 Munich, Germany
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Hallett SL, Lester RJ. Actinosporeans (Myxozoa) with four developing spores within a pansporocyst: Tetraspora discoidea n.g. n.sp. and Tetraspora rotundum n.sp. Int J Parasitol 1999; 29:419-27. [PMID: 10333325 DOI: 10.1016/s0020-7519(98)00228-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Two species of marine actinosporeans with spores that develop in groups of four rather than eight within a pansporocyst are described. In other respects, including triradial symmetry, three polar capsules each enclosing a coiled polar filament, parasitic in invertebrates, they conform with other actinosporeans. Both new species were found in the coelom of tubificid oligochaetes collected from Moreton Bay, Queensland, Australia. Spores of Tetraspora discoidea n.g. n.sp. are disc-like, almost round in apical view and dorso-ventrally compressed in side view, whereas spores of Tetraspora rotundum n.sp. are spherical. The novel development of these two marine actinosporeans may signify other variations in the life-cycles of marine Myxozoa.
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Affiliation(s)
- S L Hallett
- Department of Parasitology, The University of Queensland, Brisbane, Australia.
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Lester RJ, Hallett SL, El-Matbouli M, Canning EU. The Case for Naming Actinosporeans using the Zoological Code. ACTA ACUST UNITED AC 1998; 14:476-7. [PMID: 17040858 DOI: 10.1016/s0169-4758(98)01331-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- R J Lester
- Department of Parasitology, University of Queensland, Brisbane, Australia 4072
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El-Matbouli M, Hoffmann RW. Light and electron microscopic studies on the chronological development of Myxobolus cerebralis to the actinosporean stage in Tubifex tubifex. Int J Parasitol 1998; 28:195-217. [PMID: 9504346 DOI: 10.1016/s0020-7519(97)00176-8] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Whirling disease caused by Myxobolus cerebralis has become the most widely known disease of salmonids in the 1990s. In the last 5 years we have studied many aspects regarding the host-pathogen relationship of this parasite. The parasite's histozoic development causes significant damage to cartilage and induces CNS symptoms by pressure on the brain and spinal cord. Myxobolus cerebralis has a two-host life-cycle involving a salmonid fish and a tubificid oligochaete. Two different stages of sporogony occur, one in each host. Early developmental stages in the fish can be found multiplying in the epidermis and peripheral and central nervous systems. The presporogenic stages then migrate to vertebral and cranial cartilages, where the first sporogonic phase occurs. Mature M. cerebralis spores found in fish cartilage are infectious for T. tubifex when ingested by the oligochaete after destruction of the infected fish. In the gut lumen of the tubificid, the spores extrude their polar capsules and attach to the gut epithelium by polar filaments. The shell valves then open along the suture line and the sporoplasm penetrates between the gut epithelial cells. The binucleate sporoplasm multiplies by schizogony, producing many one-cell stages which begin gamogonic development. As a result of the multiplication process, the intercellular space of the epithelial cells in more than 10 neighbouring worm segments may become infected. At this time (60-90 days p.i.), pansporocysts with eight zygotes start the sporogonic phase. The final stage of this development is a pansporocyst containing eight folded triactinomyxon spores. Shortly afterwards, the spores are liberated into the gut lumen. The spores reach the water either by egestion or following the death of the infected tubificids. Infected tubificids can release triactinomyxons for at least 1 year. The ultrastructure of all four phases, schizogony, gametogony, gametogamy and sporogony, is demonstrated and discussed.
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Affiliation(s)
- M El-Matbouli
- Institute of Zoology, Fish Biology and Fish Diseases, University of Munich, Germany.
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Hallett SL, O'Donoghue PJ, Lester RJG. Structure and Development of a Marine Actinosporean, Sphaeractinomyxon ersei n. sp. (Myxozoa). J Eukaryot Microbiol 1998. [DOI: 10.1111/j.1550-7408.1998.tb05082.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Lom J, Yokoyama H, Dyková I. Comparative ultrastructure of Aurantiactinomyxon and Raabeia, actinosporean stages of Myxozoan life cycles. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0003-9365(97)80043-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Andree KB, Gresoviac SJ, Hedrick RP. Small subunit ribosomal RNA sequences unite alternate actinosporean and myxosporean stages of Myxobolus cerebralis the causative agent of whirling disease in salmonid fish. J Eukaryot Microbiol 1997; 44:208-15. [PMID: 9183708 DOI: 10.1111/j.1550-7408.1997.tb05702.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The alternating myxosporean and actinosporean stages of the myxozoan parasite Myxobolus cerebralis (Hofer 1903) from its salmonid fish and aquatic oligochaete hosts, respectively, were compared for sequence homology of the small subunit (18S) ribosomal RNA genes. A 99.8% similarity between the sequences of these two stages was substantially greater than that of M. cerebralis compared to two other Myxobolus sp. from salmonid fish. Our results are the first molecular evidence confirming the alternating stages, initially described by Wolf and Markiw [25] for the life cycle of M. cerebralis but found in two different taxonomic classes (Myxosporea and Actinosporea) are indeed forms of the same organism. Sequencing of rRNA genes of the actinosporean stage followed by development of specific primers for DNA amplification of the myxosporean stage, as in our study, should be applied to solve other myxozoan life cycles. Additionally, these approaches will in the future provide useful diagnostic reagents for the detection and study of this important group of fish pathogens.
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Affiliation(s)
- K B Andree
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis 95616, USA
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Uspenskaya AV. Alternation of actinosporean and myxosporean phases in the life cycle of Zschokkella nova (Myxozoa). J Eukaryot Microbiol 1995; 42:665-8. [PMID: 8520578 DOI: 10.1111/j.1550-7408.1995.tb01612.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Experimental evidence has been gathered to show that the life cycle of the myxozoan gallbladder parasite Zschokkella nova Klokacewa, 1914, which infects the fish Carassius carassius, has a complex life cycle with alternation of two hosts (fish and Oligochaeta) and two developmental phases (myxosporean and actinosporean). The gut epithelium of the oligochaete, Tubifex tubifex, exposed experimentally to Z. nova, obtained from C. carassius, became infected with organisms resembling Actinosporea. The spore structure and cube-like network of the interconnected spores is reminiscent of Siedleckiella silesica Janiszewska, 1952, although the spores are very different in size and number of sporoplasm nuclei. The life cycle of Z. nova resembles that of the whirling disease agent Myxosoma cerebralis described by Wolf and Markiw, which also alternates between fish and oligochaete hosts.
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Affiliation(s)
- A V Uspenskaya
- Laboratory of Cytology of Unicellular Organisms, Russian Academy of Science, St. Petersburg, Russia
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Wheatley DN, Rasmussen L, Tiedtke A. Tetrahymena: a model for growth, cell cycle and nutritional studies, with biotechnological potential. Bioessays 1994; 16:367-72. [PMID: 8024545 DOI: 10.1002/bies.950160512] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Tetrahymena has been used as a model cell system in many studies of morphogenesis, conjugation, gene mapping, cell division and growth kinetics. In this article, we consider some advances which have resulted from the successful development of a chemically defined medium (CDM), and how subsequent work has extended the contribution that this organism has made to our understanding of different aspects of growth, nutrition, cell cycle control, cytokinesis and intercellular signalling. Finally, we discuss the considerable potential that has arisen for the biotechnological exploitation of this big and rapidly growing eukaryotic cell.
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Affiliation(s)
- D N Wheatley
- Cell Pathology Laboratory, University Medical School, Foresterhill, Aberdeen, UK
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