Authors: Mübeccel DURUSOY, Nuran DİRİL, A. Nihat BOZCUK, F. Zehra MULUK
Abstract: The effect of temperature on the activities of catalase and glutathione S-transferase (GST) as a function of time in ebony mutant and 0regon w.t. strains of Drosophila melanogaster is studied. The life span of ebony mutant and 0regon w.t. males at 25 ¼C is determined to be 40 and 55 days, respectively. ln both strains at 28¼C the life span decreased to about 23 days for ebony mutant and to about 32 days for 0regon w.t. The enzyme activities are determined during this period for each week. Statistically important increases are observed for both enzymes studied in both strains up to four days. The following decreases are observed in enzyme activities on later days: ebony catalase, approximately 40%; 0regon w.t. catalase, 13%; ebony GST, 33%; Oregon w.t. GST, 54%. The data show that heat stress tends to be tolerated by enzyme systems; however, when the time period of exposure to heat stress is longer, enzyme inhibition is observed and this inhibition increases by the period of temperature or ageing itself. ln these two strains with different life spans, both enzyme activities started to increase with statistically significance (p>0.01) about a week before their mortality. this increase may arrise due to a sudden induction of enzymes against heavy conditions (increase in oxidative stress, lipid peroxidation, increase in inorganic peroxides) which may occur towards the end of the life span. The same profile of the change in enzyme activities has been obtained for both enzymes in both starins.
Keywords: Drosophila melanogaster, ebony mutant, 0regon w.t., catalase, glutathione S-tranferase, heat stress, ageing.