[Ubiquitous downregulation of InR gene expression affects stress associated hormone metabolism in Drosophila females].

The effect of the ubiquitous downregulation of insulin receptor (InR) gene expression on the metabolism of juvenile hormone (JH) and dopamine (DA) in young females of D. melanogaster under normal conditions and heat stress is studied. The activity ofJH degradation and alkaline phosphatase (ALP, an enzyme regulating DA synthesis) were used as indicators of JH and DA levels, respectively.

[Inhibition of DD2R gene expression in the corpus allatum activates alkaline phosphatase in female Drosophila melanogaster].

Tissue-specific inhibition of the expression of the D2-like dopamine receptor gene (DD2R) in the corpus allatum (CA), which is a gland that synthesizes the juvenile hormone (JH), was tested for effect on alkaline phosphatase (AP) activity and the intensity of the AP response to heat stress (stress reactivity) in female Drosophila melanogaster. AP activity and AP stress reactivity in transgenic females with lower DD2R expression in the CA were higher than in control flies. A pharmacological elevation in JH increased AP activity in females of the control strains.

[Effect of the apterous56f mutation on N-acetyltransferase and alkaline phosphatase activities in Drosophila melanogaster females].

Alkaline phosphatase (AP) and N-acetyltransferase (NAT) activities were studied in 1-day-old Drosophila melanogaster females of the apterous56f (ap56f) strain, having an elevated level of the juvenile hormone (JH) and a decreased level of dopamine as a result of the mutation, and in the Canton S ancestral wild-type strain in the normal conditions and upon an experimental increase in JH titer. The AP and NAT activities in ap56f females were significantly lower than in Canton S females in the norm. JH application increased the AP activity of mutant females to the level characteristic to JH-treated wild-type females.

[The mechanism of the effect of apterous56f mutation on the reproductive function of Drosophila melanogaster].

The effects of L-dihydroxyphenylalanine (L-DOPA) and 20-hydroxyecdysone (20E) were studied with respect to the content of dopamine (DA), intensity of the juvenile hormone (JH) degradation, and fecundity of the wildtype flies (Canton S) and JH-deficient apterous56f mutants (in young females, carrying this mutation, the levels of DA and 20E production were strongly increased). Fly feeding with L-DOPA proved to increase the level of DA in a dose-dependent manner and reduce JH degradation in 2-day-old females of both strains. Feeding with 20E produced the same effect.

[Juvenile hormone controls egg laying and fertility in Drosophila virilis during starvation].

Degradation of juvenile hormone and reproductive function during starvation and experimental increase of the juvenile hormone titer were studied in wild type and mutant D. virilis females incapable to respond to heat stress by changes in juvenile hormone metabolism and fertility. After 24-hour starvation, the females of both lines were characterized by a decreased level of juvenile hormone degradation, 24-hour delay of egg laying, increased egg laying within 3 h after the termination of starvation, and decreased fertility within three days.