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Profilin Functions in Cytokinesis, Nuclear Positioning, and Stomatogenesis in Tetrahymena thermophila
Author(s) -
WILKES DAVID E.,
OTTO JOANN J.
Publication year - 2003
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.2003.tb00130.x
Subject(s) - cytokinesis , tetrahymena , profilin , biology , macronucleus , microbiology and biotechnology , phagocytosis , ciliate , cell division , cytoskeleton , actin cytoskeleton , genetics , cell
. Expression of the actin‐binding protein profilin was disrupted in the ciliate Tetrahymena thermophila by an antisense ribosome method. In cells with the antisense disruption no profilin protein was detected. Cultures of cells with the antisense disruption could be maintained, indicating that profilin was not essential for cytokinesis or vegetative growth. Disruption of the expression of profilin resulted in many cells that were large and abnormally shaped. Formation of multiple micronuclei, which divide mitotically, was observed in cells with a single macronucleus, indicating a defect in early cytokinesis. Some cells with the antisense disruption contained multiple macronuclei, which in Tetrahymena may indicate a function late in cytokinesis. The lack of profilin also affected cytokinesis in the cells that could divide. Normal‐sized and normal‐shaped cells with the antisense disruption took significantly longer to divide than control cell types. The profilin disruption revealed two new processes in which profilin functions. In cells lacking profilin, micronuclei were not positioned at their normal site on the surface of the macronucleus and phagocytosis was defective. The defect in phagocytosis appeared to be due to disruption of the formation of oral apparatuses (stomatogenesis) and a possible failure in the internalization of phagocytic vacuoles.