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Polar Tube (polar + tube)

Distribution by Scientific Domains
Medical Sciences40%

Selected Abstracts

Brachiola algerae Spore Membrane Systems, their Activity During Extrusion, and a New Structural Entity, the Multilayered Interlaced Network, Associated with the Polar Tube and the Sporoplasm

THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2002
ANN CALI
ABSTRACT. The microsporidial genus, Brachiola, contains three species: the type species Brachiola vesicularum (identified from an AIDS patient) and two species transferred from the genus Nosema, becoming Brachiola connori and Brachiola algerae. A developmental feature of the genus Brachiola is the "thickened" plasmalemma from sporoplasm through sporoblast stage. The sporoplasm has been reported to have a thick plasmalemma at 1-h postextrusion. The purpose of this investigation was to observe B. algerae spores before, during and after germination to determine if the plasmalemma is thick at the point of extrusion and if not, when and how it forms. New understandings regarding the polar filament position inside the spore, places it outside the sporoplasm proper with the sporoplasm limiting membrane imaginations surrounding it. These invaginations, present a possible location for aquaporins. The multilayered interlaced network (MIN), a new organelle (possibly of Golgi origin from the sporoblast), was observed inside the spore and sporoplasm; it formed an attachment to the end of the extruded polar tube and contributed to the thickening of the sporoplasm plasmalemma. A thin "unit limiting membrane", present on the sporoplasm at the time of extrusion, is connected to the MIN by many cross-connections forming the "thick blistered" surface by 30 min-postextrusion. [source]

Recognition profiles of microsporidian Encephalitozoon cuniculi polar tube protein 1 with human immunoglobulin M antibodies

PARASITE IMMUNOLOGY, Issue 1 2008
K. FURUYA
SUMMARY Microsporidian Encephalitozoon cuniculi has a unique organelle called a polar tube (PT), the extrusion of which is absolutely required to invade a host cell. We recently detected anti- E. cuniculi PT immunoglobulin (Ig) M antibodies in sera from many healthy individuals. The present one-dimensional (1-D) immunoblot analysis predominantly detected a band at 52 kDa in all of the examined human sera with anti-PT IgM. The use of mouse monoclonal antibody confirmed that the 52-kDa band detected in 1-D immunoblots was an antigen derived from the PT, which represents a glycoprotein nature. In addition, from changes in the immunoreactivity of the 52-kDa band before and after treatment with NaOH, we determined that the 24 human serum samples with anti-PT IgM activities could be roughly grouped into three types: (i) sera containing antibodies against only a saccharic determinant (n = 3); (ii) sera containing antibodies against only a proteinic determinant (n = 11); and (iii) sera showing dual recognition of saccharic and proteinic determinants (n = 10). Further two-dimensional (2-D) immunoblot analysis followed by proteomic analysis confirmed that human sera with anti-PT IgM reacted with E. cuniculi polar tube protein 1 (PTP1). Such circulating IgM antibodies may be important in the first line of defence against E. cuniculi infection. [source]

Paranucleospora theridion n. gen., n. sp. (Microsporidia, Enterocytozoonidae) with a Life Cycle in the Salmon Louse (Lepeophtheirus salmonis, Copepoda) and Atlantic Salmon (Salmo salar)

THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2010
STIAN NYLUND
ABSTRACT. Paranucleospora theridion n. gen, n. sp., infecting both Atlantic salmon (Salmo salar) and its copepod parasite Lepeophtheirus salmonis is described. The microsporidian exhibits nuclei in diplokaryotic arrangement during all known life-cycle stages in salmon, but only in the merogonal stages and early sporogonal stage in salmon lice. All developmental stages of P. theridion are in direct contact with the host cell cytoplasm or nucleoplasm. In salmon, two developmental cycles were observed, producing spores in the cytoplasm of phagocytes or epidermal cells (Cycle-I) and in the nuclei of epidermal cells (Cycle-II), respectively. Cycle-I spores are small and thin walled with a short polar tube, and are believed to be autoinfective. The larger oval intranuclear Cycle-II spores have a thick endospore and a longer polar tube, and are probably responsible for transmission from salmon to L. salmonis. Parasite development in the salmon louse occurs in several different cell types that may be extremely hypertrophied due to P. theridion proliferation. Diplokaryotic merogony precedes monokaryotic sporogony. The rounded spores produced are comparable to the intranuclear spores in the salmon in most aspects, and likely transmit the infection to salmon. Phylogenetic analysis of P. theridion partial rDNA sequences place the parasite in a position between Nucleospora salmonis and Enterocytozoon bieneusi. Based on characteristics of the morphology, unique development involving a vertebrate fish as well as a crustacean ectoparasite host, and the results of the phylogenetic analyses it is suggested that P. theridion should be given status as a new species in a new genus. [source]

Brachiola algerae Spore Membrane Systems, their Activity During Extrusion, and a New Structural Entity, the Multilayered Interlaced Network, Associated with the Polar Tube and the Sporoplasm

THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2002
ANN CALI
ABSTRACT. The microsporidial genus, Brachiola, contains three species: the type species Brachiola vesicularum (identified from an AIDS patient) and two species transferred from the genus Nosema, becoming Brachiola connori and Brachiola algerae. A developmental feature of the genus Brachiola is the "thickened" plasmalemma from sporoplasm through sporoblast stage. The sporoplasm has been reported to have a thick plasmalemma at 1-h postextrusion. The purpose of this investigation was to observe B. algerae spores before, during and after germination to determine if the plasmalemma is thick at the point of extrusion and if not, when and how it forms. New understandings regarding the polar filament position inside the spore, places it outside the sporoplasm proper with the sporoplasm limiting membrane imaginations surrounding it. These invaginations, present a possible location for aquaporins. The multilayered interlaced network (MIN), a new organelle (possibly of Golgi origin from the sporoblast), was observed inside the spore and sporoplasm; it formed an attachment to the end of the extruded polar tube and contributed to the thickening of the sporoplasm plasmalemma. A thin "unit limiting membrane", present on the sporoplasm at the time of extrusion, is connected to the MIN by many cross-connections forming the "thick blistered" surface by 30 min-postextrusion. [source]

Ophthalmic microsporidiosis: the Manchester experience

ACTA OPHTHALMOLOGICA, Issue 2009
R BONSHEK
Purpose We report cases of ocular and adnexal microsporidiosis diagnosed in Manchester, UK, and review the literature. Methods The archives of the National Specialist Ophthalmic Pathology (NSOPS) Manchester Laboratory and Health Protection Agency Laboratory (HPA)at Manchester Royal Infirmary were reviewed for cases of microsporidiosis between 1990 and 2009. Results 8 cases of ocular and adnexal microsporidiosis were identified. Organisms were Encephalitozoon hellem, Encephalitozoon sp., Vittaforma corneae, Trachipleistophora hominis, Nosema sp. with infection of ocular surface, cornea, nasolacrimal apparatus and nasal sinuses, and eyelid; a historical case of Microsporidium ceylonensis keratitis, first reported by Norman Ashton in 1973 was also reviewed. Ages ranged from 11 years (Ashton's case) to 50 years. One case was from an HIV +ve patient, the others were immunocompetent. At least 4 infections were contracted whilst the patient was outside the UK. Conclusion Microsporidia, minute obligate intracellular parasites related to fungi, infect via a polar tube housed within a highly resistant spore. Microsporidial infection in HIV/AIDS, usually entereic, is the most reported. Antiretroviral treatment has lowered the incidence of enteric microsporidiosis and ocular infection is increasingly prevalent and often not HIV-related. In our cases the majority were immunocompetent individuals. LM can be diagnostic if characteristic refractile ZN-positive spores are seen, but LM does not permit speciation, which usually requires EM. Diligent searching for organisms may be necessary as distribution may be focal. Insufficient data exist for PCR-based diagnosis of most microsporidial species.Sources and mechanisms of microsporidial infection remain speculative. [source]