Biomaterial Database

Ultrastructure of the oocysts, sporocysts, and sporozoites of Toxoplasma gondii. 1998

C A Speer, and S Clark, and J P Dubey

Department of Veterinary Molecular Biology, Montana State University, Bozeman 59717-3610, USA.

Transmission and scanning electron microscopy were used to study the ultrastructure of the oocysts, sporocysts, and sporozoites of the VEG strain of Toxoplasma gondii and to compare the ultrastructure of sporozoites with tachyzoites (from the peritoneum of mice) and bradyzoites (from brain tissue cysts in mice). Oocysts were surrounded by a thin veil of finely reticulate material. The oocyst wall consisted of 3 layers and contained a previously unknown disc-shaped micropyle that appeared as a depression in the oocyst wall. The sporocyst contained 4 sporozoites and a residuum of lipid and amylopectin granules. The sporocyst wall was 3-layered with the innermost layer consisting of 4 curved plates held together at sutures by an interposed strip. Exposure to excysting fluid caused the interposed strip to separate from the curved plates, which curled inward releasing the sporozoites. Sporozoites had a posteriorly located nucleus and all the organelles typical for coccidian zoites. Sporozoites, tachyzoites, and bradyzoites had similar numbers of rhoptries but differed in the numbers and sizes of micronemes, dense granules, amylopectin granules, and lipid bodies.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013047	Specific Pathogen-Free Organisms	Animals or humans raised in the absence of a particular disease-causing virus or other microorganism. Less frequently plants are cultivated pathogen-free.	Pathogen-Free Organisms,Specific Pathogen Free,Organism, Pathogen-Free,Organism, Specific Pathogen-Free,Organisms, Pathogen-Free,Organisms, Specific Pathogen-Free,Pathogen Free Organisms,Pathogen Free, Specific,Pathogen Frees, Specific,Pathogen-Free Organism,Pathogen-Free Organism, Specific,Pathogen-Free Organisms, Specific,Specific Pathogen Free Organisms,Specific Pathogen-Free Organism
D014122	Toxoplasma	A genus of protozoa parasitic to birds and mammals. T. gondii is one of the most common infectious pathogenic animal parasites of man.	Toxoplasma gondii,Toxoplasma gondius,Toxoplasmas,gondius, Toxoplasma
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus