NUCLEOLAR AND BIOCHEMICAL CHANGES DURING UNBALANCED GROWTH OF TETRAHYMENA PYRIFORMIS

Nucleolar and Biochemical Changes during Unbalanced Growth of Tetrahymena Pyriformis

Numerous nucleoli can be observed in the macronucleus of the logarithmically growing ciliated protozoan Tetrahymena pyriformis; at late log phase the nucleoli aggregate and fuse. In stationary phase this fusion process continues, leaving a very few large vacuolated nuclear fusion bodies in the nucleus. When these stationary phase cells are placed into fresh enriched proteose peptone medium, the...

Changes in the transport of mitochondrial Ca2+ during the culture growth cycle of Tetrahymena pyriformis.

The properties of the Ca2+ transport system of mitochondria, isolated in various phases of growth of static cultures of Tetrahymena pyriformis, were studied. A large increase in the endogenous energy-dependent Ca2+ content of mitochondria was observed as cultures of T. pyriformis passed through the exponential and stationary phases of growth (approx. 0.25 and 50 nmol Ca2+ per mg mitochondrial p...

Nucleolar Aging in Tetrahymena during the Cultural Growth Cycle

Nucelolar morphology was studied by electron microscopy in control and actinomycin D-treated populations of Tetrahymena pyriformis (W) during the cultural growth cycle. Nucleoli exhibit an "aging" cycle concomitant with the cultural growth cycle, but independent of the individual cell cycle. Four different stages in the course of this aging process have been defined. Stage 1 occurs upon inocula...

Ultracytochemical Observations of Glycogen Synthesis and Storage during Infradian Growth of Tetrahymena Pyriformis

Activity of Ribonuclease, Acid Phosphatase, and Phosphodiesterase in Tetrahymena Pyriformis during Growth

Studies on the nucleolytic activity of cell homogenates of Tetrahymena pyriformis indicated that enzyme activity was, among other factors, a function of the age of the culture (1, 2). It was shown that the specific activities of ribonuclease (RNase) (EC 2.7.7.h) and acid phosphatase (APase) (EC 3.1.3.2) in crude homogenates prepared from stationary-phase cultures were consistently higher than t...