Temperature sensitivity and its relations to changes in growth, control of cell division, and stability of morphogenesis inParamecium aurelia Syngen 4 stock 51
✍ Scribed by Whitson, Gary L.
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1964
- Tongue
- English
- Weight
- 789 KB
- Volume
- 64
- Category
- Article
- ISSN
- 0095-9898
No coin nor oath required. For personal study only.
✦ Synopsis
The success of Scherbaum and Zeuthen ('54) in bringing about division synchrony in mass cultures of letrahymena pyriformis has stimulated an intensified interest in the effects of temperature on growth and division in protozoa. Thormar ('59), by studies on single cells, discovered an age dependent thermal sensitivity in Tetrahymena. Scherbaum ('57) and Zeuthen ('58) concluded that this age dependent thermal sensitivity was the basis for temperature-induced synchrony in mass cultures of Tetrahymena.
In several different studies which followed, attempts were made to discover the structural and chemical nature of the underlying mechanism responsible for this temperature-induced synchrony. For instance, Scherbaum ('56) found that the mean cell size in Tetrahymena increased 3 to 4 times as a result of the temperature cycling treatment. Hamburger and Zeuthen ('57) found that heat synchronized cells, when transferred to nonnutrient medium, went through several subsequent cell divisions without any growth. Such a separation of growth from division supported the idea that cell growth and increase in cell size alone is not the "trigger" for cell division in this synchronous system. In addition, Iverson and Giese ('57) and Scherbaum et al. ('59) found that there was no direct relationship between the relative amounts of DNA and RNA in synchronized cells and cell division in Tetrahymena. Yet, thev did find that the amount of DNA and RNA in synchronized Tetrahymena was much higher than that of log phase cultures. Other biochemical studies led to the same conclusion for