A Method for Synchronous Induction of Food Vacuoles in the Macrostome Form of Tetrahymena vorax

Localization by Indirect Immunofluorescence of Tetrin, Actin, and Centrin to the Oral Apparatus and Buccal Cavity of the Macrostomal Form of Tetrahymena vorax

“…This model is strengthened by our current findings that 20H5, an antibody directed against centrin, a known calcium‐binding protein, localizes to the FFR, which surrounds the cytostome. Furthermore, the addition of calcium to a macrostomal population initiates cytopharyngeal pouch closure and subsequent food vacuole formation (Sherman, Buhse, and Smith 1981). It is especially intriguing that actin and centrin complexes have both been reported to contract in the presence of calcium (Huxley 1969; Salisbury et al 1984), and it has not escaped our attention that tetrins share some structural similarity with coiled‐coil actin‐binding proteins, such as myosin and spectrin (Brimmer and Weber 2000; Honts 1991; Honts and Williams 2003).…”

Sodium‐dependent Transport of [3H](1d)chiro‐Inositol by Tetrahymena

“…For uptake, ion dependence, competition, and inhibition experiments, 1 ml of a 72‐h culture was inoculated into 50 ml of fresh medium lacking antibiotic/antimycotic solution and incubated at 20 °C for 48 h. Cells in mid‐logarithmic phase growth were washed twice by centrifugation at 400 g into 3.7 mM phosphate buffer, pH 6.8 (Hamburger and Zeuthen 1957; Sherman, Buhse, and Smith 1981) and resuspended to a cell density of approximately 3.0 4.0 × 10 5 cells/ml. Radiolabeled (1D) chiro ‐inositol was added to a specific radioactivity of 0.66 μCi/ml.…”

A complex of iron and nucleic acid catabolites is a signal that triggers differentiation in a freshwater protozoan

“…Cell density was determined by using a Coulter Counter model ZBI. Populations in late logarithmic phase of growth were concentrated by centrifugation, washed in inorganic medium (21), pH 6.8, and suspended in inorganic medium to give a cell density of 4 ϫ 10 4 cells contained in a final volume of 100 l. Stomatin (3 mg͞ml final concentration), a stomatin fraction, or one of the synthetic inducers was added, and the cells were incubated at 20°C for 7 h. An equal volume of distilled, deionized H 2 O was used in place of the test solution as a routine control, and the particular mobile phase prepared in the same manner as the fraction was included as an additional control when appropriate. Activity was determined microscopically by counting the number of macrostomal cells in a minimum of 500 total cells.…”