Vegetative Mutants and Clonal Senility in Tetrahymena *

Eight strains of Tetrahymena pyriformis were examined in multiple daily isolation series over ∼ 800 generations. Dead and defective lineages appeared in all clones. In 7, the defective sub-lines appeared at a constant characteristic rate; the 8th showed an increasing rate of production of two defects. A breeding analysis of certain persistent morphological and growth rate variants suggests that the variations derive from macronuclear alterations. The relationship between these cellular changes and “senility” in metazoa and other protozoa is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73883/1/j.1550-7408.1959.tb03946.x.pd

The Distribution of Tetrahymena pyriformis 1

This paper is a brief account of both amicronucleate and sexually active strains of Tetrahymena pyriformis and their distribution with some comments on their possible evolution.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72276/1/j.1550-7408.1970.tb02348.x.pd