Babesia sp.: the relationship of stage of development to structure of intra- and extracellular parasites.
The relationship of stage of development to structure in Babesia rodhaini and B. microti was studied by freeze-etching, carbon replication, and thin sectioning. The trophozoites of these Babesia are surrounded by a single membrane over most of their surfaces, but in some regions of the cytoplasm, membranous structures may parallel the plasmalemma, providing a double membrane. Merozoites are produced from trophozoites by budding. An early external indication that a bud will form is the organization of a pellicle complex at the site of the bud. The trophozoite nucleus divides before bud formation starts. The pellicle forms by development of a thick subplasmalemmal layer just under the plasmalemma in a bulging area that contains one of the daughter nuclei. The subplasmalemma layer of the pellicle of babesial merozoites is similar to that of plasmodial merozoites as it is divided into a series of roughly hexagonal plates by a reticular network which resembles coarse chicken wire. Thus, not only are the merozoites of these two species of Babesia budded in a fashion similar to that by which plasmodial merozoites are budded, but they also have similar pellicles.
D000818:Animals; D001403:Babesia / Q000254:growth & development / Q000648:ultrastructure*; D002244:Carbon; D002462:Cell Membrane / Q000648:ultrastructure; D006224:Cricetinae; D004912:Erythrocytes / Q000469:parasitology; D005613:Freeze Etching; D051379:Mice; D008867:Microtomy; D013010:Sonication
D002244:Carbon