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N E Gruntenko

Publications and source records attributed to N E Gruntenko.

50 records · Page 3Linked to original sources
PubMedDate not supplied

A comparative analysis of juvenile hormone metabolyzing enzymes in two species of Drosophila during development.

The course of changes in the activities of enzymes degrading juvenile hormone (JH), epoxyde hydrolase (JHEH) and JH-esterase (JHE) was studied in two lines of Drosophila virilis (101 and 147) and in two lines of D. melanogaster (Canton-S and 921283). It was established for D. virilis that changes in the JH titre during pupal-adult development is determined by the activity level of JHE rather then JHEH, while in D. melanogaster developmental changes in JH titre are related to changes in the activity level of both JHE and JHEH. In adults of D. virilis, the high level of JH-hydrolysing activity is determined by JHE and in those of D. melanogaster by JHEH. Differences in the course of changes in the JHE activity level between adults of lines 101 and 147 of D. virilis were found, and also in the JHEH activity level between adults of lines Canton S and 921283 of D. melanogaster. It was shown that attainment of a definite JHE activity level in females of lines 101 and 147 agrees well with the onset of oviposition of fertilized eggs. The possible role of JHE in reproduction of D. virilis is discussed.

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Role of DOPA decarboxylase and N-acetyl transferase in regulation of dopamine content in Drosophila virilis under normal and heat stress conditions.

Activity levels of DOPA decarboxylase (DDC), an enzyme responsible for dopamine (DA) synthesis, and of N-acetyl transferase (NAT), an enzyme responsible for its degradation, were studied under normal and stress conditions in two lines of Drosophila virilis which are in contrast concerning their DA content under normal conditions and its alterations under stress. Interlinear differences in DDC activity were detected, and genetic analysis was carried out. It was found out that neither DDC nor NAT activity in D. virilis changed under stress. Based on the results of this study and data obtained earlier by the authors, a mechanism of DA content control under normal and stress conditions was proposed.

Acetyltransferases↗
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[The heat-shock reaction is disturbed in a Drosophila virilis strain incapable of a neurohormonal stress reaction].

Cellular stress response was investigated in two lines of D. virilis: wild type and line with disturbed neurohormonal stress-reaction. Analysis of proteins, synthesized in salivary glands of larvae of both lines under heat stress, revealed malfunction in heat shock reaction of mutant specimen. This malfunction expresses in decreased level of heat shock protein synthesis. Analysis of electrophoretic spectra of proteins from homogenates of imagoes of both lines maintained under normal conditions and those exposed to heat (38 degrees C, 60 min.) revealed correlation between protein spectrum and physiological state of the organism. Interlinear differences by proteins spectra in normal condition, controlled by a single gene (or by block of closely linked genes), were found. The question if there is a common genetic control for the neurohormonal stress-reaction and cellular stress response is discussed.

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[The dopamine system stress reaction in adults of Drosophila virilis is controlled by genes of Chromosome 6].

A linkage group of the gene responsible for changes of DA titer under stress in adults of D. virilis was determined. Line 160 of D. virilis, all autosomes of which bear visible recessive mutations, was used as an analyzer. Flies of lines 160 and 147 were shown to differ in DA content under normal conditions and in the way DA metabolic system reacts to stress. Among the offspring of the analyzing cross, groups of flies were found with one testable autosome from line 147 and all other chromosomes from line 160. Results of the DA titer measurements in flies of these groups under stress conditions have proved that the gene in question is linked to chromosome 6.

Animals↗
PubMedDate not supplied

[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. Application of exogenous juvenile hormone also led to a decreased level of its degradation and 24-hour arrest of egg laying. Experimental increase of the juvenile hormone titer before the beginning of starvation led to a sharply increased fertility (number of laid eggs and number of progenies) within the first 24 h after the termination of starvation. The dynamics of juvenile hormone degradation and of fertility were similar after starvation and upon application of the exogenous hormone. The role of juvenile hormone in the control of egg maturation and laying under stress conditions has been discussed.

Animals↗
PubMedDate not supplied

[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.

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