Ultrastructure of the cysts of Sarcocystis rangiferi from skeletal muscle of reindeer ( Rangifer tarandus tarandus )

• Published in: Canadian Journal of Zoology
• Main Author: Gjerde, Bjørn
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1985
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Rangifer tarandus
• Online Access: http://dx.doi.org/10.1139/z85-399; http://www.nrcresearchpress.com/doi/pdf/10.1139/z85-399

Cysts of Sarcocystis rangiferi from reindeer (Rangifer tarandus tarandus) were examined by transmission electron microscopy. The cysts were located within skeletal muscle cells which were encapsulated by a thick layer of connective tissue. The connective tissue capsule consisted of numerous fibroblasts and a matrix with a moderate number of collagen fibrils, and represents an analogue of the so-called secondary cyst wall of Sarcocystis gigantea and various Besnoitia species. The cysts were limited by a unit membrane, the cyst membrane, which in part was reinforced by a thin subjacent layer of electron-dense material. The cyst surface was covered by closely packed, villiform protrusions, measuring 12–14 μm in length and 8 μm in diameter. The cyst membrane formed vesiclelike invaginations at and between the bases of the protrusions. Cyst ground substance divided the interior of the cyst into numerous compartments containing metrocytes or cystozoites. The cystozoites multiplied by endodyogeny.