Light and electron microscope study of a new species of Thelohania (Microsporida) in the shrimp Pandalus jordani

Johnston, L.B.; Vernick, Sanford H.; Sprague, Victor

doi:10.1016/0022-2011(78)90190-8

Cited by 22 publications

(31 citation statements)

References 2 publications

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“…The reticulate membrane is like that which, as Vavra (1976) pointed out, has frequently been seen in association with the developing polar filament. Johnston, Vernick & Sprague (1978) found a similar reticulate stage in the developing polaroplast. Vernick, Sprague & Krause (1977) have referred to this type of memhrane as the 'reticulate phase of the Golgi apparatus' or, simply, 'Golgi reticulum', the English equivalent of the 'reticulum golgien' of Takizawa, Vivier & Petiprez (1975).…”

Section: Discussionmentioning

confidence: 73%

Electron microscopical study of a new genus and new species of microsporida in the gills of Atlantic cod Gadus morhua L.*

Morrison

Sprague

1981

Journal of Fish Diseases

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A microsporidium, forming xenoparasitie complexes (xencmas) of the cell-hypertrophy tumour type, was found in the gills of the Atlantic cod Gadus morhua L. and studied with the electron microscope. It seemed to be similar to Nosema branehiale Nemeezek, 1911, in the haddock Melanogrammus aeglefinus (L.) except in size of spore. The xenoma (cyst) was basically like the Glugea eyst and the parasite had some other characters in common with Glugea; it was apansporoblastie, unikaryotic, disporoblastie and underwent partial development in parasitophorous vacuoles. It differed from Glugea in lacking plasmodial stages, producing usually 1 or 2 spores (rather than 16) in a vacuole, showing no distinct tendency for different stages to occur in different zones of the cyst and having tubules in the parasitophorous vacuoles. The name Loma morhua n. g., n. sp. (type) was proposed and the genus assigned to the family Glugeidae Thelohan. 1892. The parasite of haddock gill was transferred to the new genus, becoming L. branchiaUs (Nemeezek, 1911) n. comb.

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Section: Discussionmentioning

confidence: 73%

Electron microscopical study of a new genus and new species of microsporida in the gills of Atlantic cod Gadus morhua L.*

Morrison

Sprague

1981

Journal of Fish Diseases

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“…This is a process which we also observed in our material. It is at variance with the series of three binary divisions of the sporogonial plasmodium, a quite nonthelohanian process, found by Johnston et al (1978) in the shrimp parasite T. butleri. The latter authors proposed that this type of division be included in the de®nition of the genus Thelohania.…”

Section: Discussionmentioning

confidence: 81%

“…In both species, the development more or less complied with that of T. maenadis, except for membranous envelopes around sporoblasts and spores within the SPV in T. cecaldii. In T. butleri from muscles of the shrimp Pandalus jordani, the authors of this species, Johnston et al (1978), described only the sporogony sequence, starting with a diplokaryotic sporont and ending with a SPV with eight spores, each with single nuclei. VivareÁ s (1975) proposed the name T. pallipedis for Thelohania populations from A. pallipes, taking account of minor dierences in spore morphology and the number of turns of the polar tube, as reported in Maurand and Vey (1973) vs. Cossins and Bowler (1974).…”

Section: Discussionmentioning

confidence: 99%

Thelohania contejeani Henneguy, 1892: dimorphic life cycle and taxonomic affinities, as indicated by ultrastructural and molecular study

Lom

Nilsen

Dyková

2001

Parasitology Research

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Thelohania contejeani is a dimorphic species with two simultaneous routes for sporogony. In the first, diplokaryotic sporonts produce 8 uninucleate spores with 9-10 turns of polar tube, within a sporophorous vesicle wall. The episporontal space contains two kinds of tubules and a spongiform mass. In the second, single diplokaryotic sporonts produce small membrane-bound compartments in which they transform into mature diplokaryotic spores with 5-6 turns of polar tube. Analysis of the small subunit (SSU) rRNA revealed two copies of 16S-like rDNA, one of them 1,311 bp, the other 1,361 bp long, with an overall identity of 93%. The majority of sequence differences were located in a 120-bp stretch between positions 336 and 456, with only 40.5% identity between the sequences. Careful consideration suggests that the shorter sequence represents a pseudogene. According to the SSU rDNA sequence, T. contejeani is not closely related to any of the microsporidians where this sequence is available and could not be unambiguously placed in the 16S phylogenetic tree.

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“…Of those species described in decapods, the majority infect the skeletal muscle (Sprague 1970, 1977, Sprague & Couch 1971, Johnston et al 1978, Couch 1983, McGriff & Modi 1983, Herbert 1987, Alderman & Polglase 1988, Lightner 1988, Overstreet 1988, Flegel et al 1992, Dennis & Munday 1994, Olson et al 1994, Clotilde-Ba & Toguebaye 1995, Childers et al 1996, Mori & Salvido 2000, Azevedo 2001), whilst some, including Pleistophora spp., can also infect heart muscle and gill, stomach, hepatopancreatic epithelial cells (Overstreet 1973) and ovary (Viosca 1943, Sprague 1970. Few microsporidians have been described infecting the hepatopancreas alone (Azevedo 1987, Anderson et al 1989.…”

Section: Introductionmentioning

confidence: 99%

Enterospora canceri n. gen., n. sp., intranuclear within the hepatopancreatocytes of the European edible crab Cancer pagurus

Stentiford¹,

Bateman²,

Longshaw³

et al. 2007

Dis. Aquat. Org.

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Only 1 genus (Nucleospora) within 1 family (Enterocytozoonidae) of the Microsporidia contains species that are parasitic within the nuclei of their host cells; to date, all described intranuclear Nucleospora spp. parasitise fish. This study describes the first intranuclear microsporidian parasite of an invertebrate, the European edible crab Cancer pagurus L. (Decapoda: Cancridae). Infected crabs displayed no obvious external signs, and maximum apparent prevalence of infection within a monthly sample was 3.45%. Infected hepatopancreatic tubules were characterised by varying numbers of hypertrophic and eosinophilic nuclei within epithelial cells. Parasite stages appeared as eosinophilic granular accumulations causing margination of host chromatin. In advanced cases, the tubule epithelia degenerated, with parasites and sloughed epithelial cells appearing in tubule lumens. All life stages of the parasite were observed within host nuclei. Uninucleate meronts were not detected, although binucleate stages were observed. Multinucleate plasmodia (sporogonal plasmodia) contained up to 22 nuclei in section, and late-stage plasmodia contained multiple copies of apparatus resembling the polar filament and anchoring disk, apparently associated with individual plasmodial nuclei. As such, aggregation and early assembly of sporoblast components took place within the intact sporogonial plasmodium, a feature unique to the Enterocytozoonidae. Liberation of sporoblasts from plasmodia or the presence of liberated sporoblasts was not observed in this study. However, large numbers of maturing and mature spores (measuring 1.3 ± 0.02 × 0.7 ± 0.01 µm) were frequently observed in direct contact with the host nucleoplasm. Considering the shared features of this parasite with microsporidians of the family Enterocytozoonidae, and the unique presence of this parasite within the nucleoplasm of decapod crustacean hepatopancreatocytes, this parasite (Enterospora canceri) is proposed as the type species of a new genus (Enterospora) of microsporidian. Molecular taxonomic work is now required, comparing Enterospora to Enterocytozoon and Nucleospora, the 2 other genera within the Enterocytozoonidae.KEY WORDS: Cancer pagurus · Crustacea · Enterocytozoon · Enterocytozoonidae · Epithelium · Hepatopancreas · Intranuclear · Nucleospora · Nucleoplasm · Nucleus Resale or republication not permitted without written consent of the publisherDis Aquat Org 75: [61][62][63][64][65][66][67][68][69][70][71][72] 2007 (Modin 1981, Elston et al. 1987, Mullins et al. 1994, Nilsen et al. 1995, Lom & Dyková 2002. The family also contains the genus Enterocytozoon, known to infect a range of mammalian and bird hosts. Although these parasites associate intimately with the host cell nuclei, intranuclear infections have not been described to date. Members of the genera Enterocytozoon and the fish-infecting Nucleospora exhibit significant structural and genetic differences from other microsporidians and are placed amongst the basal groups of the Microsporidia (Lo...

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Light and electron microscope study of a new species of Thelohania (Microsporida) in the shrimp Pandalus jordani

Cited by 22 publications

References 2 publications

Electron microscopical study of a new genus and new species of microsporida in the gills of Atlantic cod Gadus morhua L.*

Electron microscopical study of a new genus and new species of microsporida in the gills of Atlantic cod Gadus morhua L.*

Thelohania contejeani Henneguy, 1892: dimorphic life cycle and taxonomic affinities, as indicated by ultrastructural and molecular study

Enterospora canceri n. gen., n. sp., intranuclear within the hepatopancreatocytes of the European edible crab Cancer pagurus

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