Date of Award


Degree Type

Honors Paper




The initial observable event in protozoan conjugation is the union, by pairs, of cells belonging to opposite mating types. The union does not occur immediately after mixing appropriate mating types; a starvation-initiated period (the refractory period) of approximately 4 hours is prerequisite for mating between the two mating types of variety 1, Tetrahymena pyriformis employed in this study.

The results of this study indicate that water-diffusible mating substances are produced by the mating types during the refractory period. The production of these substances is initiated by placing the cells under starvation conditions and not by contacts among cells of opposite mating types as in other ciliates.

Quantitative and qualitative changes in nucleic acid derivatives of the intracellular metabolic pool of T. pyriformis were observed to accompany increased periods of starvation. There is possibility that these changes are the result of an indirect role of intracellular 260 mu absorbing compounds in the production of the mating substances.

Included in

Biology Commons



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