Accession Number : AD0664650

Title :   COLD-SHOCK-INDUCED DIVISION DELAY OF SYNCHRONIZED TETRAHYMENA: TEMPERATURE-DURATION RELATIONSHIP.

Corporate Author : NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF

Personal Author(s) : Nachtwey,D. Stuart

Report Date : 08 FEB 1968

Pagination or Media Count : 22

Abstract : Synchronized Tetrahymena were subjected to temperatures around 0C and around 10C for various durations. Cell division was delayed in excess of the duration of the cold shock in an almost all-or-none fashion: with intermediate durations of cold shocks, some cells showed long excess delays and others showed essentially no excess delay. The fraction of the population showing long excess delays was dependent upon temperature and duration; a 20 minute shock at approximately 10C elicited long excess delays in about half the population, whereas, a 35 minute shock was required for the same effect when the temperature was lowered to approximately 0C. Although the higher temperature was more effective in eliciting the long-excess-delay response than was the lower temperature, the amount of excess division delay, if produced, was about the same with shocks at both temperatures. These results suggest that a metabolically controlled response system and not overbonding of some structure are involved in cold-shock-induced division delay. (Author)

Descriptors :   (*CELL DIVISION, TEMPERATURE), (*CILIATA, CELL DIVISION), CHEMICAL BONDS, RESPONSE(BIOLOGY), METABOLISM, COLD WEATHER TESTS, EXPOSURE(PHYSIOLOGY), X RAYS

Subject Categories : Biology
      Radiobiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE