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  • 1
    Electronic Resource
    Electronic Resource
    Route of egg yolk protein uptake in the oocytes of kuruma prawn, Penaeus japonicus (1996)
    Springer
    Marine biology 125 (1996), S. 773-781 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The route of egg yolk protein uptake into the oocytes of kuruma prawn, Penaeus japonicus, was studied using immunohistochemical and electron microscopical methods. Although a significant immunofluorescence with anti-vitellin-immunoglobulin was observed in the enlarged follicle cells surrounding oil globule stage oocytes of the early vitellogenic ovary, no fluorescence was detected in shrunken follicle cells surrounding oocytes in the yolk granule stage. Electron microscopically, yolk granule stage oocytes have an irregular surface with numerous well-developed microvilli. In contrast, the surface of follicle cells is relatively smooth. The irregular surface of yolk granule stage oocytes was covered with a layer of electron dense material. Similar dense material was found in the spaces between the neighboring follicle cells on the yolk granule stage oocytes. The outer surface of the follicle cells on yolk granule stage oocytes was covered by dense materials which were similar to those found on the irregular surface of oocytes. Micropinocytotic vesicles containing dense material were found in the ooplasm near the irregular surface with numerous well-developed microvilli. Dense material was concentrated in the peripheral part of the small forming yolk bodies of yolk granule stage oocytes. This suggests that the electron dense material, probably egg yolk protein, transferred to the surface of yolk granule stage oocytes from the spaces between the neighboring follicle cells may be incorporated into the ooplasm by pinocytosis through the microvilli and subsequently aggregate to form yolk bodies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00349260
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  • 2
    Electronic Resource
    Electronic Resource
    Ultrastructure of the microgamont and microgamete of Eimeria funduli, a coccidium parasitizing killifishes (1983)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish diseases 6 (1983), S. 0 
    Details
    ISSN: 1365-2761
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Abstract. The ultrastructure of the microgamont and microgamete of the coccidium Eimerici funduli was studied in hepatocytes of the killifish Fundulus grandis and F. similis. During microgametogenesis, the nuclear chromatin condensed, marginated, then differentiated into a peripheral dense portion that became the nucleus of the microgamete and a central clear portion that remained in the gamont. Near each nucleus was a mitochondrion and four microtubules which were incorporated into the microgamete. In microgamonts, dense polysaccharide granules (50–60 nm diameter) were demonstrated with the periodic acid-thiocarbohydrazide-silver proteinate method. Flagella extended into the parasitophorous vacuole from basal bodies situated near nuclei. Microgametes budded from the surface of the microgamonts. The microgamete consisted of a nucleus, two flagella and basal bodies, a mitochondrion, a rudimentary basal body, four microlubules, a perforatorium, and a dense rod-like structure. The elongate nucleus was narrow anteriorly and bulb-like posteriorly. One of the flagella was attached to the body of the microgamete. A mitochondrion that was swollen anteriorly and constricted posteriorly ran alongside the nucleus. The four microtubules appeared to arise from a rudimentary basal body and were closely related to the mitochondrion. Two of them extended nearly the length of the nucleus. The rod-like structure appeared to develop from a thickening of the limiting membrane of the microgamont. Fertilization was not directly observed, but microgametes were found in the parasitophorous vacuoles of several macrogamonts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2761.1983.tb00050.x
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  • 3
    Electronic Resource
    Electronic Resource
    Ultrastructural effects of the coccidium, Eimeria funduli Duszynski, Solangi and Over street, 1979 on the liver of killifishes (1981)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish diseases 4 (1981), S. 0 
    Details
    ISSN: 1365-2761
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Abstract. Ultrastructural studies were made on the inflammatory response in livers of two killifishes, Fundulus grandis and F. similis, experimentally infected with the coccidium Eimeria funduli. Coinciding with the formation and development of gamonts of E. funduli, changes took place in the liver and leucocytes appeared in that organ. Near areas of developing macrogamonts, many hepatocytes degenerated whereas others contained residual bodies which indicated sublethal damage. The damage was probably associated with merozoite formation and release. Filament-rich perisinusoidal cells hypertrophied during the development of E. funduli and contributed to walling off aggregates of oocysts from uninfected liver tissue. Leucocytes involved in the host response included lymphocytes, monocytes, heterophils, eosinophils and an unidentified third type of granulocyte. The heterophil was the first granulocyte to respond to the parasite and sometimes appeared to penetrate the parasitophorous vacuole of degenerating macrogamonts. Degranulating eosinophils were often observed near damaged tissues. Both the monocyte and eosinophil were phagocytically active. The monocyte was more phagocytically active and contained both host cells and parasite debris, whereas the eosinophil contained only debris from degenerating macrogamonts. The presence of immature granulocytes in the liver suggests that at least some granulocyte formation occurred in the liver.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2761.1981.tb01136.x
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  • 4
    Electronic Resource
    Electronic Resource
    Rhabdomyosarcoma in the Japanese medaka, Oryzia latipes (Temminck & Schlegel) and guppy, Poecilia reticulata Peters (1988)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish diseases 11 (1988), S. 0 
    Details
    ISSN: 1365-2761
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Abstract. Three cases of skeletal muscle neoplasms occurring in two small fish species used in carcinogen tests are reported. The cases illustrated a wide range of histologic patterns, and consisted of a well-differentiated juvenile type, a well-differentiated pleomorphic type and a poorly differentiated pleomorphic type. A rhabdomyosarcoma with juvenile type features developed in the Japanese medaka, Oryzias latipes, exposed to 0·5 ml/1 of the solvent dimethylformamide. A pleomorphic type rhabdomyosarcoma occurred in one medaka and in one guppy, Poecilia reticulata, exposed to the carcinogen methylazoxymethanol acetate. These cases indicate the potential for skeletal muscle cells in medaka and guppy to become neoplastic but, because the tumours occurred at a low frequency, there may not necessarily be a chemical aetiology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2761.1988.tb00547.x
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  • 5
    Electronic Resource
    Electronic Resource
    Ultrastructure of the macrogamont of Eimeria funduli, a coccidium parasitizing killifishes (1983)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish diseases 6 (1983), S. 0 
    Details
    ISSN: 1365-2761
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Abstract. The ultrastructurc of the macrogamont of Eimeria funduli was studied in hepatocytcs of the killifish Funldulus grandis and F. similis. The macrogamont developed in a parasitophorous vacuole (PV) that was bounded by two unit membranes probably derived from an envelope of modified host rough cndoplasmic reticulum (RER). The membrane adjacent to the host-cell cytoplasm was lined with ribosomes. whereas the membrane facing the PV was smooth and blebbed into the PV. Intravacuolar tubules were not observed in the PV. The macrogamonts had a single limiting membrane with lew micropores. Developing macrogamonts had abundant RER. few Golgi bodies, and a few small polysaccharide granules. Nuclei of developing macrogamonts had dispersed chromatin and compact nucleoli. Polysaccharide granules in developing and mature macrogamonts were identified with the periodic acid-thiocarbohydrazide-silver proteinate technique. In mature macrogamonts, polysaccharide granules as large as 1 –2 μm in diameter nearly filled the cytoplasm. The cytoplasm contained three kinds of inclusions that were associated with either the RER or Golgi apparatus. Inclusions identified as type I wall-forming (WF) bodies were small, dense, membrane-bound granules that developed from the Golgi apparatus. Inclusions identified as type II WF bodies were usually dense, irregularly shaped bodies that occupied RER cisternae. Some type II WF bodies had a heterogeneous content but most were homogeneous. A third type of inclusion was related to the cytoplasmic aspect of RER cisternae and consisted of tubules and vacuoles enclosed in a membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2761.1983.tb00049.x
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  • 6
    Electronic Resource
    Electronic Resource
    Sequential expression of biomarkers in Bluegill Sunfish exposed to contaminated sediment (1992)
    Springer
    Ecotoxicology 1 (1992), S. 45-73 
    Details
    ISSN: 1573-3017
    Keywords: biomarkers ; Bluegill ; sediment ; pollution ; EFPC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The temporal expression of various biological rsponses was determined in Bluegill SunfishLepomis macrochirus exposed under controlled laboratory conditions to sediment containing high concentrations of polynuclear aromatic hydrocarbons, polychlorinated biphenyls and heavy metals. Liver, gill, blood, kidney, brain, spleen and intestine were removed from Sunfish sampled at 1, 2, 4, 8, 16, and 40 weeks post-exposure. Biomarker data were recorded for specific proteins, enzymatic activities, DNA integrity, and histopathology. Biomarkers in the laboratory exposed fish were similar to those of indigenous Sunfish sampled from the site of origin of the contaminated sediment. Several patterns of development of biomarkers over time were also evident. For example, the responses of certain biomarkers are not time-dependent (i.e., intestine and gill ATPase activities) while that of others, such as brain ATPase activity, liver cytochrome P450 and NADPH content, stress proteins, chromatin proteins and DNA strand breaks, fluctuate over time. Still other biomarkers, such as EROD activity, zinc protoporphyrin content of the blood, and DNA adducts, showed marked increases over time. Such patterns need to be considered when comparing laboratory and field results and deciding which biomarkers to use for biomonitoring programs. Implications for natural selection and population/community level responses are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00702655
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