ONTOGENETIC PROFILE OF THE GLUTATHIONE S-TRANSFERASE ACTIVITY IN MUSCA DOMESTICA L.

Background. Musca domestica L. can transmit pathogens, and therefore poses serious threats to human and animal health. M. domestica is known as a model organism for studying the physiology and biochemistry of insects, the mechanisms of insecticidal resistance, as well as the development and testing of insecticides. The issue of insecticide resistance in insects is a concern all over the world; therefore, the study of insect enzymes is very important for a more complete understanding of the mechanisms underlying resistance to insecticides. Purpose. To study the ontogenetic profile of glutathione-S-transferase activity in Musca domestica L. Materials and methods. The glutathione-S-transferase activity was determined in M. domestica of laboratory (TY and UF) and field (Nov and Nik) strains at different ontogenetic stages. 1-Chloro-2,4-dinitrobenzene was used as the substrate and the optical density was recorded at 340 nm in kinetic mode. Specific activity was calculated taking into account the non-enzymatic transformation of the substrate, the dilution factor of the homogenate, and the protein content in the sample and was expressed as the change in optical density in 1 minute per mg of protein. Results. The results obtained indicate changes in glutathione-S-transferase activity during the life cycle of M. domestica, both in laboratory and in field strains. Differences are observed between different stages of ontogenetic development. The enzyme activity in insects of the Lab TY strain was higher than that of the UF strain at almost all stages of the insect life cycle. For field strains, the GST activity was higher in specimens of the Nov strain compared to that of the Nik strain. Conclusion. The differences of the GST activities in flies between two field strains may be due to differences in insecticidal load in the insect catching locations. The identified differences between flies of the laboratory and field strains may be associated with different genetic information. This may be related to the expression of certain enzyme isoforms, since the expression of enzymes can be influenced by various factors, including environmental factors, so that qualitatively different forms can be selected at the genetic level and differentially expressed. The results can be applied to the design of insect population management programs.