On Some Regularities of Genetic Control of Drosophila Stress Reaction

Abstract

The heat-shock response was studied in Drosophila virilis strains with normal and impaired neurohormonal stress reaction. Flies from the latter strain were shown to have the impaired heat-shock response. In this strain, transcription 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 stress reaction: in flies of both strains, the stress exposure resulted in an increase in the dopamine content and in a decrease in the activity of tyrosine decarboxylase (the first enzyme of dopamine synthesis) and in the level of juvenile hormone degradation. However, stress reactivity in mutant individuals differed from that in flies that did not carry stress-related mutations.