Ref ID : 7570
Glenn K. Walker, Timothy K. Maugel, and Dennis Goode; Encystment and Excystment in Hypotrich Ciliates I. Gastrostyla steinii. Protistologica XVI(4):511-524, 1980
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Fine structural analysis of encystment and excystment in Gastrostyla steinii reveals expected similarities and some striking differences to previously studied protozoa. Cyst wall formation includes an initial release of ectocyst precursor followed by a layering of mesocyst components in a "cross hatched" arrangement. Numerous macronuclear microtubules are noted during encystment in regions of nuclear fusion. The mature cysts, however, reveals no macronuclear or cytoplasmic microtubules, including a complete absence of kinetosomes and cilia. Microtubular disassembly also proceded in the presence of 60% deuterium oxide. Subsequent differentiative events in excystment include the assembly of kinetosomes, cilia and microtubules; membrane elaboration for the increase in surface area, and macronuclear amitosis.