On some regularities of genetic control of Drosophila stress reaction

The heat-shock response was studied in Drosophila virilis strains with norm al and impaired neurohormonal stress reaction. Flies from the latter strain were shown to have the impaired heat-shock response. In this strain, trans cription of the heat shock gene hsp83 is reduced and synthesis of all heat shock proteins is suppressed. The neurohormonal stress reaction (status of dopamine, octopamine, and juvenile hormone metabolic systems) was examined in D. melanogaster strains having normal and impaired heat-shock response. The impairment of this response did not prevent the development of the stre ss reaction: in flies of both strains, the stress exposure resulted in an i ncrease in the dopamine content and in a decrease in the activity of tyrosi ne decarboxylase (the first enzyme of dopamine synthesis) and in the level of juvenile hormone degradation. However, stress reactivity in mutant indiv iduals differed from that in flies that did not carry stress-related mutati ons.