Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    In vitro Development of First-Generation Schizonts of Eimeria canadensis (Bruce, 1921) (1973)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 20 (1973), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. In vitro development of Eimeria canadensis from cattle was studied in monolayer cultures of various bovine cell lines grown on coverslips in Leighton tubes. Excysted sporozoites were used for inoculation of the cell cultures. Sporozoites entered the host cells within a few minutes, but apart from a reduction in the number of refractile bodies, changed little in appearance during the first 9 days. Beginning at 91/2 days postinoculation, sporozoites developed into sporozoite-shaped schizonts or, less frequently, transformed into trophozoites. Sporozoite-shaped schizonts with as many as 8 nuclei were observed transforming into spheroid schizonts. At 111/2 days, intermediate schizonts had a characteristic single mass of refractile granules and 60–80 nuclei. Deep invaginations, which resulted in the formation of several blastophores, usually occurred when schizonts had about 100 nuclei. Merozoites were formed as a result of radial outgrowth from the surface of spheroid schizonts as well as of blastophores. Mature merozoites were seen 1st after 13 days.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1973.tb00880.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Ultrastructural development of first- to second-generation merozoites in Eimeria contorta Haberkorn, 1971 (1975)
    Springer
    Parasitology research 47 (1975), S. 91-101 
    Details
    ISSN: 1432-1955
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of first-generation merozoites to second-generation schizonts and merozoites of Eimeria contorta in one of its natural hosts, the mouse, was investigated with the electron microscope. Merozoites inside a host cell show a marked U-shape and a degeneration of the inner pellicular membrane complex prior to transformation into schizonts. These processes closely resemble those seen in transforming sporozoites. In young schizonts with about 3–5 nuclei, the Golgi-adjuncts (structures of unknown function) form a large interconnected network. Nuclear divisions in growing schizonts involve the formation of a centrocône, which develops in a pocket-like indentation of the nuclear envelope. At least one centriole is present immediately adjacent to this indentation. In a later stage, the centrocône forms a conical nuclear protrusion directed towards a merozoite-anlage. This developing merozoite contains anlagen of a conoid, of rhoptries, and of micronemes and a refractile body in addition to the nucleus, centrioles, and a Golgi-adjunct. The merozoite-anlage is limited by a triple unit membrane complex. Schizonts give rise to 8–15 second-generation merozoites. Interesting features of these merozoites are the high number of micronemes, the finding of one single large mitochondrion per merozoite, and the occurrence of 26 subpellicular microtubules, i.e. the same number as in sporozoites of E. contorta. At the end of their development, merozoites come into direct contact with the host cell cytoplasm as the parasitophorous vacuole breaks down.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00382632
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    In vitro development of first- and second-generation schizonts of Eimeria contorta haberkorn, 1971 (coccidia, sporozoa) (1973)
    Springer
    Parasitology research 41 (1973), S. 173-185 
    Details
    ISSN: 1432-1955
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Sporozoites of Eimeria contorta inoculated into monolayer cultures of bovine embryonic kidney cells and Madin-Darby bovine kidney cells developed to mature second-generation schizonts, which were first seen 72 hr after inoculation. In cultures of bovine embryonic intestine cells, only mature first-generation schizonts developed. Intracellular sporozoites became U-shaped before transforming into trophozoites with a prominent refractile body. Sporozoite-shaped schizonts were not seen. At 30 hr after inoculation, merozoites began to form as conical protrusions of the surface of schizonts with 25–35 nuclei. Mature first-generation schizonts (25 by 20μ), with 25–35 merozoites each having two refractile bodies, were first observed at 46 hr. The merozoites averaged 9.5 by 2.0 μ. After enough sodium taurocholate to make a concentration of 0.01% was added to the cultures, merozoites left their host cells, entered others and transformed into trophozoites within 4 hr. Merozoite formation frequently began with the appearance of conical protrusions at opposite poles of second-generation schizonts. During the late stages of their development, the 8–15 merozoites were spirally arranged around the central residual body. Mature schizonts and merozoites averaged 19 by 8.5 μ and 22.5 by 1.4 μ, respectively. In some cultures, larger schizonts with 30–40 merozoites, arranged rectilinearly with respect to the residual body, were observed. On the basis of a comparison with the corresponding stages of E. nieschulzi, it is concluded that E. contorta is a valid species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00329485
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    In vitro development from sporozoites to first-generation merozoites in Eimeria contorta Haberkorn, 1971 (1975)
    Springer
    Parasitology research 47 (1975), S. 23-34 
    Details
    ISSN: 1432-1955
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The asexual development of Eimeria contorta from sporozoites to first-generation merozoites in tissue culture was investigated with the electron microscope. Sporozoites with a three-layered pellicle, 26 subpellicular microtubules, a conoid, 4–7 rhoptries, and an abundance of micronemes actively entered host cells and showed direct contact to the host cell's cytoplasm. Shortly after penetration, small vacuoles surrounding the parasite merged into a parasitophorous vacuole. Inside this vacuole, sporozoites assumed a definite U-shape before transformation into schizonts took place. This process was characterised by the occurrence of subpellicular microtubules exclusively in the anterior half of the sporozoite, by a degeneration of the 2 inner pellicular membranes, by an outpocketing of the parasite's surface, and by the arrangement of microtubules in clusters. About 25 merozoites were formed at the surface of mature schizonts, to which they remained attached at their posterior pole. A polar ring was present at that area. Anterior and posterior refractile bodies were conspicuous in merozoites and showed close association with mitochondria. The significance of a fibrillar substructure in rhoptries and micronemes is discussed, and special attention is drawn to the pathway of nutrient transport from host cell mitochondria and dictyosomes through intravacuolar folds, parasitophorous vacuole and crescent body into the parasite's food vacuoles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00418062
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...