Time of completion of early and late encystation phases (after initiation of encystation)

Range completion of early phase ~10 hours: completion of late phase 16 hours after initiation of encystation
Organism Protozoa Giardia lamblia
Reference Adam RD. Biology of Giardia lamblia. Clin Microbiol Rev. 2001 Jul14(3):447-75 DOI: 10.1128/CMR.14.3.447-475.2001 p.461 left column 4th paragraphPubMed ID11432808
Primary Source [83] Erlandsen SL, Macechko PT, van Keulen H, Jarroll EL. Formation of the Giardia cyst wall: studies on extracellular assembly using immunogold labeling and high resolution field emission SEM. J Eukaryot Microbiol. 1996 Sep-Oct43(5):416-29PubMed ID8822813
Method Primary source abstract: "The process of encystment was studied by localizing cyst wall specific antigens with immunofluorescence for light microscopy and immunogold staining for field emission scanning electron microscopy."
Comments P.461 left column 4th paragraph: "Encystation can be divided into two phases, early and late. The timetables determined by various studies have differed somewhat, probably because of the different approaches used. After the initiation of encystation conditions, the organisms do not all enter the encystation process at the same time. Therefore, morphologic studies that examine the time course of the first encysting organisms tend to give earlier times for the encystation events than studies that depend on pooled organisms. These morphologic studies indicate that the early phase is complete within about 10 h and the late phase is complete by 16 h (primary source). For this discussion, [investigators] will assume that the early and late events from the various studies are comparable." Primary source abstract: "Chronological sampling of Giardia cultures stimulated with endogenous bile permitted identification of an intracellular and extracellular phase in cyst wall formation, a process which required a total of 14-16 h. The intracellular phase lasted for 8-10 h, while the extracellular phase, involved the appearance of cyst wall antigen on the trophozoite membrane, and the assembly of the filamentous layer, a process requiring an additional 4-6 h for completion of mature cysts."
Entered by Uri M
ID 117081