Sergey V Mylnikov

Effect of melatonin and pineal peptide preparation epithalamin on life span and free radical oxidation in Drosophila melanogaster.

It was shown previously that epithalamin delays age-related changes in reproductive and immune systems and increases the life span of mice and rats. These effects could be mediated by stimulating influences of epithalamin on synthesis and secretion of melatonin and on free radical processes. A comparative study on the effect of epithalamin and melatonin on both the life span of Drosophila melanogaster (strain HEM) and on the intensity of lipid peroxidation and activity of antioxidative enzymes in their tissues was the main aim of this work. Melatonin and epithalamin was added to the nutrition medium (100 micrograms/ml) during 2-3rd age of larvas. For survival analysis the flies were passed (five coupes per vessel) each 3-7 days. Lipid peroxidation was evaluated as the level of ketodienes (KD) and conjugated hydroperoxides (CHP) in fly tissues at the age of 11 days. Activity of Cu, Zn-superoxide dismuatse (SOD) and catalase was evaluated as well. The mean, median and maximum life span (MLS) were estimated. Mortality rate (MR) was calculated as alpha in the Gompertz equation (R = Ro (exp alpha t) and mortality rate doubling time (MRDT) as in 2/alpha. These parameters in groups of male and female flies exposed to melatonin and in male flies exposed to epithalamin were no different from the parameters for controls. However, exposure to epithalamin was followed in females by a significant increase in mean life span (by 17%, P < 0.02), of median (by 26%), of MLS by 14% and by a 2.12 times decrease of MR (P < 0.01) and MRDT (by 32%) compared with female controls. The level of CHP and KD in the tissues of male control flies was 40 and 49% less than that in females and indirectly correlates with male life span. Exposure to melatonin was followed by a decrease in the level of CHP and KD in females and the deletion of sex differences in them. Exposure to epithalamin significantly decreased the level of CHP and KD in female flies compared to controls (2.3 and 3.4 times, respectively, P < 0.001). Exposure to melatonin failed to influence the activity of catalase in males but increased it in females by 24% (P < 0.02) and failed to influence SOD activity both in males and females. Exposure to epithalamin was followed by a significant increase in activity of catalse, 20% in males and 7% in females and by an increase in SOD activity in males (41%). Thus, it was shown that exposure to epithalamin significantly increases the mean life span and MLS of female D.melanogaster and slowed down their aging rate by 2.12 times. This effect is in good agreement with the inhibiting effect of epithalamin in lipid peroxidation processes in fly tissues.

Pineal peptide preparation epithalamin increases the lifespan of fruit flies, mice and rats

Treatment with pineal peptide preparation epithalamin was followed by the increase of the mean lifespan of female D. melanogaster, SHR mice, C3H/Sn mice and LIO rats by 11-31% (P < 0.05). Ninety percent mortality as well as maximum lifespan were increased in fruit flies, C3H/Sn mice and rats. Mortality rate was decreased by 52% in D. melanogaster, by 52% in rats, by 27% in C3H/Sn mice. It did not change in SHR mice exposed to epithalamin. Treatment with the pineal peptide increased MRDT in flies, C3H/Sn mice and rats. It has been shown that epithalamin increased synthesis and secretion of melatonin in rats and inhibits free radical processes in rats and in D. melanogaster. It is suggested that antioxidative properties of epithalamin lead to increased lifespan of three different animal species.

Mining Gene Expression Data for Pollutants (Dioxin, Toluene, Formaldehyde) and Low Dose of Gamma-Irradiation

General and specific effects of molecular genetic responses to adverse environmental factors are not well understood. This study examines genome-wide gene expression profiles of Drosophila melanogaster in response to ionizing radiation, formaldehyde, toluene, and 2,3,7,8-tetrachlorodibenzo-p-dioxin. We performed RNA-seq analysis on 25,415 transcripts to measure the change in gene expression in males and females separately. An analysis of the genes unique to each treatment yielded a list of genes as a gene expression signature. In the case of radiation exposure, both sexes exhibited a reproducible increase in their expression of the transcription factors sugarbabe and tramtrack. The influence of dioxin up-regulated metabolic genes, such as anachronism, CG16727, and several genes with unknown function. Toluene activated a gene involved in the response to the toxins, Cyp12d1-p; the transcription factor Fer3’s gene; the metabolic genes CG2065, CG30427, and CG34447; and the genes Spn28Da and Spn3, which are responsible for reproduction and immunity. All significantly differentially expressed genes, including those shared among the stressors, can be divided into gene groups using Gene Ontology Biological Process identifiers. These gene groups are related to defense response, biological regulation, the cell cycle, metabolic process, and circadian rhythms. KEGG molecular pathway analysis revealed alteration of the Notch signaling pathway, TGF-beta signaling pathway, proteasome, basal transcription factors, nucleotide excision repair, Jak-STAT signaling pathway, circadian rhythm, Hippo signaling pathway, mTOR signaling pathway, ribosome, mismatch repair, RNA polymerase, mRNA surveillance pathway, Hedgehog signaling pathway, and DNA replication genes. Females and, to a lesser extent, males actively metabolize xenobiotics by the action of cytochrome P450 when under the influence of dioxin and toluene. Finally, in this work we obtained gene expression signatures pollutants (dioxin, toluene), low dose of gamma-irradiation and common molecular pathways for different kind of stressors.

Effect of pineal tetrapeptide on antioxidant defense inDrosophila melanogaster

Effect of synthetic pineal tetrapeptide L-Ala-L-Glu-L-Asp-L-Glu (Epithalon) on specific catalase activity and the content of conjugated hydroperoxides in highly inbredDrosophila melanogaster lines differing in reproductive functions were studied. It was shown that Epithalon is a potent modulator of the antioxidant defense, whose biological activity 1000-fold surpasses that of the complex pineal peptide preparation Epithalamin.

Approaches to study microevolutionary phenomena in natural chironomid populations. Nonequilibrium as a stable state of the population

The frequencies of disk sequences in the polytene chromosomes from the salivary glands of the larvae of three species of chironomids (Diptera, Chironomidae) are analyzed. Statistically significant deviations of the population structure from the structure expected by the Hardy-Weinberg equilibrium law are detected. The distribution of frequencies in individuals with different levels of heterozygosity in the Camptochironomus tentans populations is examined. The influences of the driving and stabilizing selection on the population’s genotype are uncovered. A methodology for estimating the influence of different disk sequences on the species’ adaptability based on single collections is proposed. The stability of the nonequilibrium in the studied populations is noted and interpreted as a sign of homeostasis.

A statistical approach to the problem of the taxonomic status and evolutionary potential of a non-biting midge, Prodiamesa olivacea Meigen, 1818 (Diptera, Chironomidae, Prodiamesinae) based on karyotype analysis

The frequency of the contacts between polytene chromosomes via their centromeric and telomeric regions in the karyotype of the non-biting midge Prodiamesa olivacea has been analyzed. The fact that the groups of centromeric contacts are nonrandom and match the diploid chromosome number, equal to ten, has been statistically confirmed. The species is announced as a transitional form that evolves towards a reduction in the chromosome number.

Antimutagenic effects of synthetic epithalon peptide in mice Mus musculus different in hair color

Synthetic epithalon demonstrates differences in the antimutagenic activity after cyclophosphamide injection in mice with different hair color. We demonstrated protective effects in white mice, but not in grey ones. These effects may be explained by the different neuro-humoral status and stress-resistance of the animals.