Ref ID : 4706
M. Umberta Delmonte-Corrado, Paola Ramoino, Edoardo Margallo, and Tina Crippa-Franceschi; Macronuclear DNA Content in Exautogamous Lines Displaying Temperature Resistance Variations in the Clonal Life Course of Paramecium primaurelia. Arch.Protistenk 131:113-119, 1986
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In order to investigate the cell conditions which account for the temperature resistance oscillating trend during the clonal life in Paramecium primaurelia, the macronuclear Feulgen-positive content has been measured by fluorescence cytophotometry at succeeding fission levels in the early clonal life course up to 34 exautogamous generations. The increasing fission age is correlated to the decreasing DNA content; however, this reduction is characterized by temporary rises of the values. The correlation between DNA content and temperature resistance occurs in the second half of the clonal life considered, when the trend of DNA content displays significant variations between each value and the succeeding one. This kind of relationship indicates that the cell situation which accounts for a greater and a lower temperature resistance capability, is characterized by a lower and a greater macronuclear DNA content respectively. By assuming that the cell membrane composition changes in the clonal life course together with the changes in temperature resistance, it is interesting to indicate the relation between the membrane composition change and the DNA content variation.