EFFECT OF X-RADIATION ON THE GROWTH AND DIVISION PROCESS OF TETRAHYMENA PYRIFORMIS,
Abstract
Shortly after the beginning of x-irradiation a division block was imposed on exponentially replicating cells of Tetrahymena pyriformis and thereafter no cell division was observed for several hours. However, following x-irradiation Tetrahymena grew exponentially and increased in volume. The volume distribution of control and x-irradiated culture was lognormal. Furthermore, small cells originating from cells at the beginning of the division cycle grew at the same rate as large cells originating from cells which were close to division. This indicates that cell growth is independent of the cell division cycle to a significant extent. X-irradiation caused a temporary inhibition of the incorporation of tritiated thymidine into the DNA of cells, but DNA synthesis was resumed during irradiation, followed exponential kinetics even after x-irradiation was discontinued and stopped shortly before synchronous division. Thus, some biochemical adaptation of DNA synthetic mechanisms takes place during irradiation. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 12, 1966
- Accession Number
- AD0640546
Entities
People
- P. Schmid
Organizations
- Naval Radiological Defense Laboratory