Temperature shifts affect cell cycle progression in green algae

0469986 - MBÚ 2017 JP eng A - Abstrakt
Zachleder, Vilém - Bišová, Kateřina - Vítová, Milada - Ivanov, Ivan
Temperature shifts affect cell cycle progression in green algae.
Book of Abstract of the 17th International Conference on the Cell and Molecular Biology of Chlamydomonas. Kyoto, 2016.
[17th International Conference on Cell and Molecular Biology of Chlamydomonas. 26.06.2016-01.07.2016, Kyoto]
Grant CEP: GA ČR GA15-09231S
Institucionální podpora: RVO:61388971
Kód oboru RIV: EA - Morfologické obory a cytologie

Temperature is one of the key factors affecting growth rates and cell cycle progression in green algae. Within the optimal temperature range, the increase of cultivation temperature by ten degrees will speed up the metabolic processes by a factor of two. Increase in temperature will also affect the cell cycle progression so that more daughter cells are formed within shorter time at higher temperatures. We have been intrigued by kinetics of the growth and cell cycle progression response immediately upon temperature shifts either to temperature ten degrees lower or higher in the green alga Desmodesmus (Scenedesmus) quadricauda. At specific light intensity, the D. quadricauda cells divided into 8-celled coenobia at both temperatures, but the length of the cell cycle was about 24 hours at optimal temperature 30°C and doubled to about 48 hours at 20°C. DNA, RNA and bulk protein content approximately doubled in cells grown at the higher temperature. The cultures grown at 20°C or 30°C were at different time points transferred to the other temperature into dark to avoid growth interference. It had pronounced effect on cell cycle progression; the cells transferred from 20°C to 30°C divided into more cells than committed at 20°C, the division occurred sooner and faster than in control conditions. The cells transferred from 30°C to 20°C mostly divided only nuclei and not cells and even then to significantly lower percentage than the control cells in dark at 30°C. This suggested that the same cell state (cell size, amount of RNA, protein, activity of proteins) was perceived differently at different temperatures. We did not observe significant differences in the amount, kinetics of increase or degradation of RNA, protein nor starch after the dark transfer between treated and respective control conditions implying bulk macromolecules and their metabolism are not responsible for the observed phenomenon.
Trvalý link: http://hdl.handle.net/11104/0268272