[The enzymes of juvenile hormone metabolism in Drosophila virilis ontogeny]

Time-related changes in the activity of enzymes that degrade the juvenile hormone, epoxide hydrolase, and juvenile hormone esterase, was studied in two strains (101 and 147) of Drosophila virilis. The changes of the juvenile hormone titer during the pupal-imaginal development of D.virilis are determined by the juvenile hormone esterase activity, rather than epoxide hydrolase. Among the two forms of juvenile hormone esterase present in D. virilis, one is diisopropylphosphofluoridate-sensitive and active during the studied period, while the other, diisopropylphosphofluoridate-sensitive, is present only during metamorphosis and before flight of imago and is practically absent in sexually mature individuals. Interstrain differences were shown in the activity of the diisopropylphosphofluoridate-insensitive form in the D. virilis imago. It was shown that achievement of a certain level of its activity in females of strains 101 and 147 agrees quite well with the timing of oviposition. A possible role of this form of the juvenile hormone esterase in reproduction of D. virilis is discussed.