The fine structure of the nuclei of Tetrahymena pyriformis throughout the cell cycle.
The fine structure of the nuclei of logarithmically growing Tetrahymena pyriformis, strain HSM, was studied at 30-minute intervals throughout the cell cycle. Organisms were selected at similar stages of cytokinesis by means of a braking pipette, incubated, fixed in OsO(4), and embedded in agar to facilitate subsequent preparation for electron microscopy. Aggregates of micronuclear chromatin underwent a decrease in density and number with a concomitant increase in size throughout interphase. There were no impressive changes in macronuclear morphology. It was found possible to estimate a cell's progress through interphase by observation of micronuclear morphology, but attempts to correlate changes in fine structure with periods of DNA synthesis were unsuccessful.
D002455:Cell Division; D002467:Cell Nucleus / Q000166:cytology*; D004247:DNA / Q000096:biosynthesis; D066298:In Vitro Techniques; D008854:Microscopy, Electron; D013768:Tetrahymena / Q000166:cytology*
D004247:DNA