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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 2094

Colin G. Ogden; An ultrastructural study of division in Euglypha (Protozoa: Rhizopoda). Protistologica XV(4):541-556, 1979

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The ultrastructural events accompanying binary fission in two species of Euglypha, E. acanthophora and E. strigosa, are described. An intact nuclear envelope persists throughout division; cytoplasmic microtubules which may influence nuclear elongation converge on polar microtubule organising centres (MTOC). Microtubules of the nuclear spindle either abut on chromosomes or extend from pole to pole where they converge on the nuclear envelope adjacent to the MTOC. In the cytoplasm the single Golgi apparatus breaks down into small stacks of saccules which surround the MTOCs; the perinulear region of granular endoplasmic reticulum is dispersed early in nuclear division and is reformed around the daughter nuclei; the contractile vacuoles are shared between the daughter cells during the early stage of division and are replicated later. A band of microfilaments holds the two cells together, after the break down of the organic seal between the apertures, prior to separation. The formation of mitochondria occurs, after division, in newly separated cells.