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Regulation of retrotransposon activity in somatic tissues is a complex mechanism that has still not been studied in detail. It is strongly believed that siRNA interference is main mechanism of retrotransposon activity regulation outside the gonads, but recently was demonstrated that piRNA interference participates in retrotransposon repression during somatic tissue development. In this work, using RT-PCR, we demonstrated that during ontogenesis piRNA interference determinates retrotransposon expression level on imago stage and retrotransposons demonstrate tissue-specific expression. The major factor of retrotransposon tissue-specific expression is presence of transcription factor binding sites in their regulatory regions.

Plant polyphenols are characterized by a wide range of biological activities, including antioxidant properties, and have a high geroprotective potential. The purpose of this work was to investigate the effect of the extract of rowan berries (Sorbus aucuparia L.) on the lifespan and stress resistance of Drosophila melanogaster with the identification of possible mechanisms of its biological activity. It has been established that an ethanol extract of S. aucuparia berries, the main components of which are rutin and cyanidin-3-rutinoside, has a pronounced antioxidant activity in vitro. At the same time, treatment with rowan berry extract increased the resistance of D. melanogaster males to starvation, but reduced resistance to hyperthermia. In females, the extract reduced resistance to oxidative stress but increased resistance to hyperthermia. The effects of rowan berry extract on longevity depended both on its concentration and on the sex of fruit flies. In response to treatment with rowan berry extract, D. melanogaster males and females showed slight differences in the background level of expression of cellular stress response genes, including heat shock genes (hsp27, hsp68, and hsp83), oxidative stress resistance genes (hif1, nrf2, and sod1), circadian rhythm genes (clk and per), and the longevity gene sirt1, which may explain the differences in the observed effects.

The Gagr gene is a domesticated gag retroelement gene in Drosophila melanogaster, whose function is associated with the stress response. The protein products of the Gagr gene and its homologues in different Drosophila species have a highly conserved structure; however, they demonstrate variability in the promoter region of the gene, which is apparently associated with the gradual acquisition of a new function and involvement in new signaling pathways. In this work, we studied the effect of oxidative stress induced by ammonium persulfate on the survival of various species of the genus Drosophila (D. melanogaster, D. mauritiana, D. simulans, D. yakuba, D. teissieri, and D. pseudoobscura), analyzed the correlation between the structure of promoter regions and stress-induced changes in the expression of the Gagr gene and its homologues in different Drosophila species, and compared the stress-induced changes in the expression of oxidative stress markers: the Jak-STAT signaling pathway activator gene upd3, Jak-STAT pathway effector vir-1, and IMD signaling pathway target Rel. It was found that in D. simulans and D. mauritiana sensitivity to ammonium persulfate is significantly increased, which correlates with a reduced level of transcription of vir-1 gene orthologues. The latter is due to a decrease in the number of binding sites for the transcription factor STAT92E, a component of the Jak-STAT signaling pathway, in the vir-1 promoter region. Consistent changes in the expression of the Gagr, upd3, and vir-1 genes are observed in all species of the melanogaster subgroup, except for D. pseudoobscura, which indicates an increase in the role of Gagr in the regulation of stress response pathways during the phylogenesis of the genus Drosophila.

The enzymes involved in the transsulfuration pathway and hydrogen sulfide production-cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST) - play an important cytoprotective role in the functioning of the organism. Using CRISPER/Cas9 technology, we obtained Drosophila strains with deleted cbs, cse, and mst genes as well as with double deletion of cbs and cse genes. We analyzed the effect of these mutations on the pattern of protein synthesis in the salivary glands of third instar larvae and in the ovaries of mature flies. In the salivary glands of strains with cbs and cse deletions, a decrease was found in the accumulation of the FBP2 storage protein containing 20% methionine amino acid residues. In the ovaries, changes were detected in the level of expression and isofocusing points of proteins involved in cell protection against oxidative stress, hypoxia, and protein degradation. It was shown that in the strains with deletions of transsulfuration enzymes the proteins have a similar degree of oxidation to that of the control strain. A decrease in the total number of proteasomes and their activity was found in the strains with deletions of the cbs and cse genes.

The Drosophila melanogaster Maleless (MLE) protein is a conserved helicase involved in a wide range of gene expression regulation processes. A MLE ortholog, named DHX9, was found in many higher eukaryotes, including humans. DHX9 is involved in diverse processes, such as genome stability maintenance, replication, transcription, splicing, editing and transport of cellular and viral RNAs, and translation regulation. Some of these functions are understood in detail today, while most of them remain uncharacterized. Study of the functions of the MLE ortholog in mammals in vivo is limited by the fact that the loss of function of this protein is lethal at the embryonic stage. In D. melanogaster, helicase MLE was originally discovered and studied for a long time as a participant in dosage compensation. Recent evidence indicates that helicase MLE is involved in the same cell processes in D. melanogaster and mammals and that many of its functions are evolutionarily conserved. Experiments in D. melanogaster revealed new important MLE functions, such as a role in hormone-dependent regulation of transcription and interactions with the SAGA transcription complex, other transcriptional cofactors, and chromatin remodeling complexes. Unlike in mammals, MLE mutations do not cause embryonic lethality in D. melanogaster, and the MLE functions are possible to study in vivo throughout ontogenesis in females and up to the pupal stage in males. The human MLE ortholog is a potential target for anticancer and antiviral therapies. Further investigation of the MLE functions in D. melanogaster is therefore of both basic and applied importance. The review discusses the systematic position, domain structure, and conserved and specific functions of MLE helicase in D. melanogaster.

CP190 protein is one of the key components of Drosophila insulator complexes, and its study is important for understanding the mechanisms of gene regulation during cell differentiation. However, Cp190 mutants die before reaching adulthood, which significantly complicates the study of its functions in imago. To overcome this problem and to investigate the regulatory effects of CP190 in adult tissues development, we have designed a conditional rescue system for Cp190 mutants. Using Cre/loxP-mediated recombination, the rescue construct containing Cp190 coding sequence is effectively eliminated specifically in spermatocytes, allowing us to study the effect of the mutation in male germ cells. Using high-throughput transcriptome analysis we determined the function of CP190 on gene expression in germline cells. Cp190 mutation was found to have opposite effects on tissue-specific genes, which expression is repressed by CP190, and housekeeping genes, that require CP190 for activation. Mutation of Cp190 also promoted expression of a set of spermatocyte differentiation genes that are regulated by tMAC transcriptional complex. Our results indicate that the main function of CP190 in the process of spermatogenesis is the coordination of interactions between differentiation genes and their specific transcriptional activators.

During the process of spermatogenesis, the proliferation of spermatogonia (stem cell descendants) is replaced by their differentiation in growing spermatocytes responsible for the preparation to meiosis, which is accompanied by a cardinal change in transcriptional programs. We have demonstrated that, in drosophila, this process is accompanied by a splash of the expression of β-subunit of nascent polypeptide-associated complex (NAC) associated by ribosomes. Nascent polypeptide-associated complex is known as a chaperone involved in co-translational protein folding. This is the first case of the detection of tissue-specific co-translational NAC cofactor in multicellular eukaryotes. It is proposed that spermatocyte specific NAC is involved in the modulation of the expression of the proteins that provide the functioning of subsequent stages of spermatogenesis.

Adaptation to contrasting environments can facilitate ecological divergence and sympatric speciation. Factors that influence the probability and tempo of these processes are poorly known. We performed an evolutionary experiment on Drosophila melanogaster in order to attain better understanding of adaptation dynamics and to model the initial steps of sympatric speciation. In our experiment, several populations are being cultured either on standard rich medium (RM) or on nutrient-deficient starch-based medium (SM). After 10 generations, experimental populations demonstrated unexpected changes in their fitness: on the starch medium, flies grown on RM (FRM) outcompeted those that were cultured on SM (FSM), while on the rich medium, FRM were outcompeted by FSM. That is, experimental populations demonstrated higher fitness on the foreign medium, but were outcompeted by the aliens on the one they had been accustomed to. To explain the paradox, we hypothesize that the observed low fitness of FSM on SM was due to maternal effect, or the "effect of starving mother". The FSM flies are probably better adapted to SM, but the phenotypic outcome of their adaptations is obscured because the females grown on the poor medium invest less in their offspring (for instance, they may produce nutrient-deficient eggs). Larvae hatched from such eggs develop successfully on the rich medium RM, but experience delayed growth and/or lower survival rate on the nutrient-deficient medium SM. To test the hypothesis, we measured the fitness of the flies FSM after culturing them for one generation on RM, in order to remove the assumed maternal effect. As expected, this time FSM demonstrated higher fitness on SM compared to control flies (FRM) and to FSM before the removal of the maternal effect. The results support the idea that non-adaptive phenotypic plasticity and maternal effects can mask adaptation to adverse environments and prohibit ecological divergence and speciation by allowing the migrants from favourable habitats to outcompete resident individuals in adverse ecotopes despite the possible presence of specific adaptations in the latter.

We have shown previously that the polymorphic structure of the limk1 gene in drosophila leads to changes in LIMK1 content and to defects in courtship behavior, sound production, and learning/memory. The results of the present study of three wild-type strains and mutant agn(ts3) with altered limk1 structure demonstrate that long-term memory is normal in Canton-S and Oregon-R but is impaired in Berlin and drastically suppressed in agn(ts3). This temperature-sensitive mutant carries the S-element from the Tc1/mariner family insertion near the dlimk1 3'-UTR and, compared to Canton-S, has a reverse pCREB distribution in adult neuromuscular junctions (NMJ) of the second dorsal imago nerve before and after learning. Moreover, only agn(ts3) demonstrates amyloid-like aggregate formation in NMJ. This suggests that this impedes pCREb transport and thereby impairs the formation of short- and long-term memory.

We found increased viability in heterozygous carriers of hsf heat shock transcription factor n comparison with wild type. The effect depends on temperature, sex and direction of crosses. Viability effect is more evident in conditions of soft temperature stress. The males are more sensitive. The maternal effect is observed: if hsf*allele came from mother, the viability effect is stronger. The survival curves of heterozygotes on hsf-1 and hsf-4 alleles are similar in spite of HSF-4 protein is slightly active on normal temperature.

This paper studies the metabolism of the juvenile hormone, which affects gonads functioning in Drosophila melanogasterfemales under P-M hybrid dysgenesis. It is shown that dysgenic females grown at 29°C have increased levels of the juvenile hormone (its degradation and stress reactivity are reduced), which apparently is a compensatory response to ovarian hypoplasia.

The neuroprotective activity of apolipoprotein E (apoE) peptide mimetic Cog1410, containing amino acid sequence of the receptor-binding domain apoE, has been investigated in transgenic lines of Drosophila melanogaster expressing human APP and beta-secretase. Expression of two transgenes caused neuropathological processes attributed to Alzheimer's disease: neurodegeneration, cognitive abnormality and amyloid deposits formation in brain. It was shown that Cog 1410 reduces neurodegeneration in brain of transgenic flies and improves cognitive functions (odor recognition). These data suggest that Cog1410 is a potential neuroprotector that can be used in AD treatment.

Heat shock proteins (Hsp) provide cellular and whole body adaptation of animals to various adverse environmental conditions. Hsp70 is apparently the major player underlying biological adaptation in all organisms studied so far. In all animals the regulatory regions of studied heat shock genes include several conservative promoter elements HSEs (heat shock elements) that are necessary for binding of heat shock transcription factor (HSF). The promoter regions of hsp70 genes are extremely conserved and, hence, it was generally accepted that they are universal and can operate in species belonging to different phyla. In the present work we performed the comparative analysis which revealed characteristic differences in the hsp 70 promoters of two Diptera species: Drosophila melanogaster and highly thermotolerance soldier fly Stratiomys singularior. We measured promoters activity in D. melanogaster cell culture exploring in vitro luciferase reporter assay. The analysis demonstrated significantly higher strength ofD. melanogaster promoters in spite of the fact that comparable numbers of HSEs are present in both species. These drastic differences in the promoter strength are probably due to absence of GAF-binding sites, which are necessary for efficient functioning of D. melanogaster hsp70 promoters. In contrast, comparison of hsp83 promoters isolated from these two species does not show significant differences. Our results demonstrate existence of different evolutionary trends in the regulation of the hsp70 expression even within the same order (Diptera).

The influence of suppression of the expression of the Drosophila insulin-like receptor gene (InR) in corpus allatum (the gland-synthesizing juvenile hormone) on octopamine and juvenile hormone metabolism and on the development of the stress-reaction in Drosophila melanogaster females was studied. It was demonstrated that the suppression of InR gene expression in corpus allatum induces in D. melanogaster females an increase in the activity of the enzyme that limits the rate of octopamine synthesis (tyrosine decarboxylase), as well as in the level of juvenile hormone degradation and the intensity of the response of octopamine and juvenile hormone metabolism systems to heat stress. It was mentioned that a decrease in InR gene expression in corpus allatum does not influence the activity of OA-dependent N-acetyltransferase (the enzyme that degrades octopamine). It was established that the influence of suppression of the InR gene expression in corpus allatum on octopamine metabolism is mediated by juvenile hormone, since the processing of flies by exogenous juvenile hormone restores the activity oftyrosine decarboxylase in flies with decreased InR expression in corpus allatum up to the normal level.

The heat shock transcription factor (HSF) is a universal activator of hsp gene expression in eukaryotes. A temperature sensitive Drosophila melanogaster strain (hsf4) with a mutation in the hsfgene was originally described as a strain lacking the transcription of hsp genes in response to heat shock. Our results demonstrated that physiological function of HSF4 is not fully abrogated after heat exposure and is able to recover even after severe heat stress, causing the induction of hsp gene expression. We have studied the kinetics of accumulation and degradation of hsp gene products at transcriptional and translational levels and shown that induction of hsp genes, particularly hsp68, in mutant strain is weaker than that in the wild type. Thus, despite the fact that the HSF4 causes a delayed ac- tivation of hsp, response to heat shock in hsf4 strain remains defective.

The review deals with the available literary data on different aspects of Drosophila melanogaster vital functions in the conditions of real and modeled microgravity. The developmental stages, embryogenesis and aging, specifically, and behavioral reactions are discussed. The presented results of morphological as well as molecular genetic analyses are indicative of structural changes in early Drosophila embryos and their compensation during subsequent development, and formation of an adaptive gene-expression pattern in microgravity.

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. We demonstrated that, under normal conditions, the ubiquitous inhibition of the InR gene expression in D. melanogaster females induced an increase in the JH degradation and ALP activity. As we have already shown, this is indicative of the decrease in the concentration of the above hormones. It was also found that the total inactivation of InR does not affect the initiation ofJ H and DA metabolic system response to heat stress; however, it does affect its intensity. Thus, the involvement of the insulin signaling pathway in the regulation of the JH and DA metabolism in Drosophila females was demonstrated in vivo under normal and stress conditions.

Mitosis, cytokinesis and nuclear texture of wing imaginal discs cells silenced by UAS-RNAi-dlg construct induced by 1096-Ga 14 driver were studied. The silencing construct contains coding region of dlg gene and the complementary region. Further, this RNA hairpin (Dietzl et al., 2007) is processed by endogenous protein Dicer and the resulting RNA fragments silence mRNA dlg. Tumor suppressor gene dlg is encoding for 21 transcripts. The construct UAS-RNAi-dlg inactivates 14 transcripts--RE, RH, RQ, RS, RG, RD, RL, RB, RK, RR, RT, RN, RA, RP--and does not silenced the other 7 (RO, RF, RI, RU, RJ, RC, RM). This permits to study functions of proteins containg guanilate-kinase domain IPR008145 at C-end of the protein. The most important consequences of the silencing are abnormal mitotic exit and the formation of binuclear cells. Quantitative fluorescence measurements of anti-H3-p histone and DAPI signals showed phase-specific changes in nuclear texture. The inactivation of cellular cortex polarization is the most likely target of dlg inactivation in mitosis.

DNA replication begins from multiple sites distributed thoughout the genome and named replication origins. Despite the increasing amount of data on the properties of replication origins, it is still unknown what factors(s) is the primary determinant of ORC localization. Su(Hw) is a zinc-finger protein that is responsible for the activity of the best-studied Drosophila insulators. Here, we show that insulator protein Su(Hw) recruits histone acetyltransferase complex SAGA and chromatin remodeler dSWI/SNF to Su(Hw)-dependent insulators and creates platform for ORC binding. We have found that Su(Hw) is necessary for chromatin remodeling and ORC recruitment regardless of type of surrounding chromatin. Thus, global chromatin state does not influence molecular mechanism underlying ORC positioning in the genome, rather DNA-binding proteins are key determinants that create proper chromatin structure for ORC binding. Su(Hw) is the first example of such a protein.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the loss of neurocortical and hippocampal synapses that precedes amyloidosis and neurodegeneration and closely correlates with memory impairment. Mutations in the amyloid precursor protein (APP) cause familial AD and result in the increased production of amyloid-beta-protein (Abeta). To gain insights into synaptic effects of APP, we expressed APP, mutant form APP-Swedish and BACE in the motor neurons of fly larvae. We have shown that targeted expression of APP (APP-Swedish) in Drosophila larval motor neurons causes significant morphological and functional changes in neuromuscular junctions (NMJs): a dramatic increase in the number of synaptic buttons and changes in exocytosis as revealed by incorporation of the styryl dye FM4-64. Analysis of the number and distribution of mitochondria showed that motor neurons overexpressing APP (APP-Swedish) had a significant reduction of functional mitochondria in the presynaptic terminal. Significant synaptic abnormalities were observed for APP (APP-Swedish) and human beta-secretase (BACE) resulting in secretion of amyloid beta protein (Abeta). We suggest that APP participates in regulation of synaptic functions and its elevated expression leads to synaptic pathology independently from neurotoxic effects of Abeta.

Complexes of Piwi proteins and Piwi-interacting RNAs (piRNAs) carry out the repression of transposable elements in animal gonads. The Piwi protein clade is represented in D. melanogaster by three members: Piwi, Aub and Ago3. Piwi protein functions in the nuclei of somatic and germinal ovarian cells, whereas Aub and Ago3 are cytoplasmic proteins of germinal cells. Aub and Ago3 interact with each other in the perinuclear nuage organelle to perform piRNA amplification via the ping-pong mechanism. Previously, derepression of several transposable elements as a result of mutations in the piRNA silencing system was shown. Here we quantify the increase in expression level of an enlarged number of retrotransposons due to the mutations in the piwi gene, nuage components coding aub, mael and spn-E genes and the RNA helicase armi gene mutation that impairs Piwi nuclear localization, but not the ping-pong cycle. We reveal that piwi, armi, aub, spn-E and mael genes participate together in the repression of several transposons (HMS-Beagle, Gate and HeT-A), whereas silencing of land G elements requires the same genes except piwi. We suggest that Armi has other functions besides the localizing of Piwi protein in the nuclei. Our data suggest also a role of cytoplasmic Aub, Spn-E and Mael nuage proteins in Piwi-mediated repression of Gate and HMS-Beagle transposons in the germline nuclei. As a whole, our results corroborate the idea that genome stabilization in the germline is realized by different silencing strategies specific for different transposable elements. At the same time, our data suggest the existence of yet unknown mechanisms of interplay between nuclear and cytoplasmic components of the piRNA machinery in the germline.

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. DD2R was assumed to mediate the inhibitory effect of dopamine of JH synthesis in the CA of D. melanogaster.

Changes of nuclear texture in mitotic cells of Drosophila melanogaster imaginal discs were studied. The distribution of voxels DAPI fluorescence intensities was used as the quantitative measure of the nuclear texture. The integral characteristics such as the portion of voxels with a given fluorescent signal level and autocorrelation of pixel intensities were used. We showed the nuclear texture has specific changes at different mitotic stages and this can be used for more precise staging of mitosis. Colchicines treatment pathologies, connected to abnormal mitoses, by nuclear-texture approach.

Methods of physical DNA mapping and direct visualization of replication and transcription in specific regions of genome play crucial role in the researches of structural and functional organization of eukaryotic genomes. Since DNA strands in the cells are organized into high-fold structure and present as highly compacted chromosomes, the majority of these methods have lower resolution at chromosomal level. One of the approaches to enhance the resolution and mapping accuracy is the method of molecular combing. The method is based on the process of stretching and alignment of DNA molecules that are covalently attached with one of the ends to the cover glass surface. In this article we describe the major methodological steps of molecular combing and their adaptation for researches of DNA replication parameters in polyploidy and diploid tissues of Drosophyla larvae.

The formulation of "histone code" theory brings active investigations of the role of histone modifications and other supramolecular factors of DNA condensation in transcription regulation. In this work, we have analyzed the localization of methylated histones on 9, 36 and 79 lysines, hyperacetylated H4 histone, and subunits of cohesion complex DRAD21 relatively of Drosophila melanogaster polytene chromosomes chromatin condensation. We propose the hypotheses of a cascade regulation of transcription activity defined by histone modifications and the adaptive role of sister chromatids cohesion in the transcription of high active and extensive genes.

Experiments show that moderate caloric restriction in normal (non-sterile) fruit flies results in the increase of life span. It has been found recently that life span increases under caloric restriction also in sterile Drosophila females. This fact was explained by remodeling of metabolism due to insulin signaling. In this paper a hypothesis is put forward that under caloric restriction in the organism, the energy arrival decreases so that the stationary state must be restored. To achieve this, reproduction is reducing, remodeling of metabolism and the increasing of substrates output from the gastrointestinal tract start. The increase of life span can be just a side effect of these processes. Simulation demonstrates that the experimentally observed life span increasing in non-sterile fly females under caloric restriction can be explained exclusively by the reducing reproduction.

Specificity of regulation of genes expression at the transcriptional and posttranscriptional levels is typical for spermatogenesis in Drosophila and mammals, including humans. It becomes apparent in the existence of testis specific NXF (nuclear export factor). We have shown that the Dm NXF1 (SBR) protein is present in considerable amounts at all stages of the spermatogenesis. Using the antibody for the C-terminal part of the Dm NXF1 protein we have shown the cytoplasmic localization of the Dm NXF1 protein at early stages of the spermatogenesis. This protein is localized in the nuclear envelope at the stage of rounded spermatid. During the period of elongation, the Dm NXF1 protein has a polar localization, and is located only along one side of the extended spermatid nucleus. At the stage of spermatid individualization, this protein in the form of large cytoplasmic granules moves to the tail of the spermatozoon.

Alzheimer's disease (AD) is a progressive neurodegenerative disease whose main pathomorphological sign is synapse degeneration in the cortex and hippocampus. Abnormal synaptogenesis precedes amyloidosis and neurodegeneration and correlates with memory impairment during the early clinical phase. Mutations in the amyloid precursor protein (APP) gene cause familial AD and enhance the secretion of amyloid-beta-protein (Abeta). However, it remains unclear in what way APP and Abeta are involved in synaptic disorder in the absence of visible amyloid structures. In this study, the role of the human APP gene in synaptogenesis in transgenic lines of Drosophila melanogaster whose nerve cells express the human APP695 isoform, truncated APPs, and the presynaptic marker synaptotagmin driving the sequence of the green fluorescent protein. The expression of APP and its truncated forms caused a decrease in the synaptotagmin content of antennal lobes and mushroom lobes of the D. melanogaster brain, as well as neurodegeneration that progressed with age. The results suggest that that abnormal synaptogenesis and neurodegeneration occur in the Drosophila brain in the absence of Abeta. It is assumed that impaired cellular functions of APP and secretion of Abeta independently contribute to the pathogenesis of AD.

An analysis of the quantitative data obtained by processing the confocal images showed that the early variability of expression patterns of zygotic segmentation genes in Drosophila drastically decreases by the time of the onset of gastrulation. The following components of variability were examined: the scatter of the levels of gene expression in different embryos, the time and sequence of the formation of expression domains, the type of their formation, and the domain positioning. It was found that the positioning error at the level of zygotic genes is dynamically filtered with time.

The effect of xenobiotics on protein oxidative damage and lifespan of Drosophila melanogaster Meig., line Oregon-R, was studied. Addition of the uncoupler 2,4-dinitrophenol (DNP) to the nutritional mixture results in an induction of synthesis of heat shock proteins and increase of lifespan of insects, whereas sodium nitroprusside (SNP) has negative effect on flies viability connected, probably, with activation of processes of proteins oxidative damage. It is shown that DNP essentially corrects the SNP negative action on insects' survival rates and this "normalizing" action is revealed both at a level of sensitivity of flies to exogenic stresses and protein carbonils level and at a level of insects lifespan as a whole. It is supposed that DNP protects from SNP negative action on flies viability by reduction of intensity of free radicals production and/or induction of heat shock proteins synthesis. Consequence of that is reduction of oxidative proteins damage degree and increase of survival rate (life span) of flies.

A review of the available data on molecular mechanisms underlying the regulation of gene expression by the developmental hormone ecdysone and juvenile hormone. Heterodimer ESP/USP is the main ecdysone receptor in D. melanogaster. Structures similar to ESP/USP were found in other insects. The information about molecular-genetic mechanisms of the effect of juvenoids is less definite. It has been proposed that the juvenile hormone in insects is a modulator of the ecdysone effect.

A newly found locus of the Drosophila melanogaster genome, named toothrin (tth) has been used to study the role of the conserved domain 2/3 of genes from the d4 family. In contrast to the 2/3 domain of all vertebrates studied (including humans), which is always accompanied by the d4 domain, the tth gene contains the sequence encoding the 2/3 domain but lacks that encoding the d4 domain. The tth gene overexpression has been studied using the two-component system UAS-GAL4. It has been demonstrated that the tth overexpression at the third-instar larval (prepupal) stage decreases survival rate, simultaneously causing a substantial deceleration of development in Drosophila. It is known that the change of developmental stages in Drosophila is controlled by the rates of the expression of ecdysteroid and juvenile hormones (JHs). It is supposed that the overexpression of the tth gene causes either a shift in the ecdysterone-to-JH ratio (through a decreased JH decay rate or a delayed initiation of ecdysone synthesis) or a deceleration of the release of ecdysterones synthesized.

The genetic expression system of gene radius incompletes was studied by substituting regions of chromosome 3 from line th st sr ca, which has drastically reduced ri expression, to regions of chromosome 3 from a "selection" line ri s having very high expression of this gene. Virtually all chromosome 3 was shown to carry polygenes controlling phenotypic expression of oligogenic mutation ri. Chromosome regions making large (as well as small and even negative) contributions to sizes of the distal and proximal fragments of the latitudinal wing vein were found. These results suggest that the genetic system of expression does not correspond to the generally accepted postulates of K. Mather on equal, small, and additive contributions of polygenes.

Transgenic Drosophila stocks were selected. These stocks contained human ngf and bdnf genes under Drosophila heat-shock promoter. The expression of foreign genes during Drosophila development was demonstrated with Northern and whole mount hybridization.

Here we studied the response to heat shock in a desert D. melanogaster strain TT capable of living and propagating at 32 degrees C and the standard Oregon R strain. The TT strain proved to be more resistant to extreme temperatures. On the other hand, the observed high thermotolerance of the strain was not accompanied by a higher level of HSP70 synthesis. Conversely, reliably smaller amounts of HSP70 were synthesized in the TT strain as compared to Oregon R under all shock temperatures except the critical one (39.5 degrees C). Differences in both the structure of HSP70 genes and the pattern of all heat shock proteins have been observed between the studied strains. The role of the heat shock system in the adaptation to hyperthermia is discussed.

To elucidate the role of heat shock proteins (HSP) in the formation of resistance to extreme factors and in the development of organismic and cell response to these factors, thermotolerance in a Drosophila melanogaster line with defective HSP synthesis was studied with regard to several criteria: (1) survival of adult-females; (2) damage to egg chambers in ovarioles; (3) dynamics of oviposition; (4) frequency of loss and nondisjunction of sex chromosomes in meiosis of females exposed to a heat shock (HS). According to all these criteria, the l(l)ts403 females were more sensitive to a HS 37 degrees C, the exposure at 37 degrees C for 1 h (HS37) than the females of the wild-type line Canton S. Only the data on the first three aforementioned parameters were indicative of thermotolerance development. In files exposed to HS35 followed by HS37, a decrease in nondisjunction and loss of sex chromosomes in the 3- and 4-day ovipositions was observed as compared to the flies exposed to HS37 only. This can be explained by the differences in oviposition dynamics and, consequently, in the realization rate of the oogenesis stages in these two experimental variants. The pleiotropic effect of the l(l)ts403 mutation that led to a disturbance in HSP gene expression at the posttranscriptional level and to an increase in the frequency of sex chromosome nondisjunction in the meiosis of females exposed to HS37 suggests that these processes were connected. As no thermotolerance was revealed by studying the sex chromosome nondisjunction, but thermotolerance was found by estimating the other parameters, we suggest that the product of the gene studied is involved in a signal system operating at a stage that precedes the HS-induced changes in the translation and division apparatuses of a cell.

The metabolism of juvenile hormone (JH) was studied in two lines of Drosophila melanogaster selected for differences in mating behavior. The lines were tested under normal conditions and after short-term heat shock. Females of the HA line (selected for high male mating activity) were shown to exhibit a high level of JH hydrolyzing activity under normal conditions. By contrast, females of the LA line (selected for low male mating activity) and males of both lines had a low level of JH hydrolysis. Stress exposure resulted in a decrease of JH hydrolysis in females of the HA line; this effect was absent in females of the LA line and males of both lines.

Glycoprotein with biochemical characteristics that allow us to classify it as a glycoprotein of mucin-type was isolated from cultured embryonic cells of Drosophila melanogaster. This is the first finding of mucin-type glycoprotein in insects. Using high-affinity monoclonal antibodies against a carbohydrate epitope, we demonstrated that the accumulation of this glycoprotein in the culture fluid of Drosophila cell line and cultured cells of other insects was inhibited by secretion inhibitors. 20-hydroxyecdysone, a hormone responsible for molting and metamorphosis in insects, inhibits the accumulation of this glycoprotein in the culture fluid, as well as in cells of Drosophila Dm cell line. In another cell line (Schneider-2), where there was practically no secretion of this glycoprotein, the hormone induced its increased accumulation in the cells. Mucin glycoproteins recognized by monoclonal antibodies have been found in embryos, imaginal disc, fat body, testicles, and ovaries, but not in salivary glands or muscles of Drosophila.

Restoration of cell proliferation and repair of chromosome damage (chromatin agglutination, pulverization, or aggregation) in conditions of disturbed synthesis of heat shock proteins (HSPs) was studied in nerve ganglia of Drosophila melanogaster larvae. Two approaches were used to suppress the heat shock response: (1) anaerobic heating of wild-type Canton S larvae at 37 degrees C for 13 min, which temporarily blocked HSP gene expression at the transcriptional level [1], and (2) aerobic heating of mutant l(1)ts403 larvae at 37 degrees C for 30 min, which disturbed HSP gene expression at the posttranscriptional level [2]. The duration of heat treatment was selected according to the period of regression of heat shock puffs [3]. In both experimental systems, the period of HSP synthesis and the delay in resuming cell proliferation and recovering from mitotic chromosome stickiness increased similarly, compared to corresponding positive control. This suggests the involvement of HSPs in repairing chromatin protein damage leading to chromosome stickiness and in resuming cell proliferation. An increase in the number of cells with morphologically abnormal (pulverized or aggregated) chromatin was observed only after heat treatment for 30 min (rather than for 13 min). However, the patterns of changes in the number of such cells in Canton S and l(1)ts403 larvae recovering from 30-min heat treatment differed from one another. Different mechanisms responsible for induction of chromosome abnormalities (premature condensation of interphase chromosomes or disturbed condensation of mitotic chromosomes) and different roles of HSP in these processes are discussed.

The effect of heat stress on the system of degradation of juvenile hormone (JH) and on fertility of Drosophila virilis and D. melanogaster was studied. In wild-type strains of both species, stress resulted in delay of oviposition and in a decrease in JH hydrolysis and fertility, which lasted for several days after heat treatment. Experimental repression of juvenile hormone esterase showed that stress response of the Drosophila reproductive system is determined by the decrease in JH hydrolysis. Fertility of Drosophila strains that did not respond to stress by decreasing JH degradation level was not reduced under stress. The role of JH metabolism in Drosophila reproduction under stress and in adaptation of natural Drosophila populations to stressful environments is discussed.

Juvenile hormone (JH) metabolism in two lines of Drosophila melanogaster adults was studied under normal conditions and after short-time heat stress. Females of the line Cy/L; D/Sb were shown to have high JH hydrolysis levels which to decreased when they experienced heat stress by decreasing its level, Genetic analysis of differences in the level of JH metabolism in lines 921283 and Cy/L; D/Sb of D, melanogaster under normal conditions was performed. It was established that the trait studied was inherited according to the incomplete dominance type. It was shown that these differences were controlled by the gene (genes) localized in chromosome 2.

The interrelationship between the level of peroxidation lipid and longevity was studied as based on highly inbred lines of Drosophila melanogaster, bred for adaptively important characters. The concepts of the free-radical theory proved valid for the lines and failed to be supported for the crosses. The dominant role of heterosis in the protecting against the "aging action" of free radicals is postulated.

Genetic structure and variation of seven natural Drosophila populations was analyzed at nine enzyme loci. The populations examined exhibited low levels of genetic polymorphism and heterozygosity (Hobs = 0.096). Interpopulation variation accounted for only 1.3% (Fst = Gst = 0.013), and the populations examined were shown to be genetically similar, as Dn did not exceed 0.001.