RESUMEN
Transgenic strains of Drosophila melanogaster capable of expressing a cDNA fragment corresponding to open reading frame (ORF) of the gene for the German cockroach densonucleosis virus capsid protein VP2 (ORF VP2) in specific tissues and at a certain stage of development depending on the type of chosen driver strains (GAL-UAS system) were obtained. The ORF VP2 transcription was examined at the imago stage after crossing the obtained transgenic Drosophila with the driver line expressing the inducer protein (GAL4) under control of actin promoter (the ORF VP2 expression is induced in all tissues of the first-generation Drosophila). It was demonstrated that the greater part of transcribed foreign RNA was represented by three spliced variants in which RNA fragments either between nucleotides 137 and 353 or between nucleotides 609 and 1925 were excised; the third spliced variant was represented by RNA lacking both introns. Using the next-generation sequencing (NGS) technique, the proportion of unspliced form relative to spliced variants of the analyzed RNA was assessed. It was shown that the ratio of unspliced form to the identified spliced variants of the analyzed RNA was approximately 1:6. It is suggested that splicing of viral RNA foreign to Drosophila can be a sort of defense mechanism preventing the large-scale production of the capsid protein, potentially hazardous to the host organism.
Asunto(s)
Blattellidae/virología , Proteínas de la Cápside/biosíntesis , ADN Complementario/biosíntesis , Animales , Animales Modificados Genéticamente , Proteínas de la Cápside/genética , Densovirus/genética , Drosophila melanogaster/genética , Regulación del Desarrollo de la Expresión Génica , Sistemas de Lectura Abierta/genética , Empalme del ARN/genéticaRESUMEN
Previously, extremely low, nanomolar concentrations of the mitochondria-targeted plastoquinone derivative SkQ1 (10-(6'-plastoquinonyl) decyltriphenylphosphonium) were shown to prolong the lifespan of male and female Drosophila melanogaster by about 10 % (Anisimov et al., Biochemistry (Moscow) 73:1329-1342, 2008). Using long-term monitoring of SkQ1 effects on the Drosophila lifespan, we analyzed different integral parameters of Drosophila survival and mortality under SkQ1 treatment. Meta-analysis was used to evaluate the average SkQ1 effect measured in terms of standard deviation. The effect appeared to be 0.25 for females and 0.18 for males, which corresponds to a low effect by Cohen's "Rules-of-Thumb". The SkQ1 effects on the Drosophila lifespan were reproducible over six years and showed no relationship to fluctuations in the mean lifespan of the w(1118) line used in the experiments, methods of preparation and administration of the drug, seasons, or calendar years. Adding SkQ1 to fly food was associated with a reduction in early mortality and a decrease in random variation in lifespan. All survival curves were fitted by Gompertz function. Analysis of the Gompertz function parametric plane demonstrated significant differences between points corresponding to experimental and control cohorts. The Strehler-Mildvan correlations for 11 experiments with females and for 7 experiments with males were calculated. The significant increase in the slope of the regression lines indicated that feeding flies SkQ1 reduced the rate of fall of fly vitality and, consequently, slowed aging. These findings indicated that the SkQ1 effect on lifespan was associated with both elevation of life quality and slowing of aging.
Asunto(s)
Drosophila melanogaster/fisiología , Longevidad/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Plastoquinona/análogos & derivados , Animales , Femenino , Depuradores de Radicales Libres/metabolismo , Longevidad/fisiología , Masculino , Mitocondrias/metabolismo , Modelos Animales , Plastoquinona/metabolismo , Plastoquinona/farmacología , Especies Reactivas de Oxígeno/metabolismo , Reproducibilidad de los ResultadosRESUMEN
It was previously found that 20 pM SkQ1 (10-(6'-plastoquinonyl) decyltriphenylphosphonium) solution increased lifespan of virgin females and males of the fruit fly Drosophila melanogaster with maximal and highly reproducible effect on early survival of females. In this paper we demonstrate that SkQ1 solution of the same concentration does not increase lifespan of mated females and males, early effect on female survival being absent, whereas early fertility and the total number of progeny are elevated in treated flies. Increase in fertility observed in young mated females instead of increase of survival typical for young virgin females might illustrate the trade-off between the fly's lifespan and reproduction.