Nutritional programming of lifespan: Excessive sugar consumption in early adulthood curtails Drosophila survival by inhibiting dFOXO
Ontology highlight
ABSTRACT: Fruit flies were maintained either 40% sugar or 5% sugar diets for one week, then on 5% sugar for one further week. Whole flies were sampled at the end of weeks 1 and week 2. Persistent effects of past high sugar diets are identified.
Project description:Gene expression changes in response to aging, hyperoxia, hydrogen peroxide, ionizing radiation, and heat stress were compared using microarrays. While aging shared features with each stress, aging was more similar to the stresses most associated with oxidative stress (hydrogen peroxide, hyperoxia, ionizing radiation) than to heat stress. Aging is associated with down-regulation of numerous mitochondrial genes, including electron-transport-chain (ETC) genes and mitochondrial metabolism genes, and a sub-set of these changes was also observed upon hydrogen peroxide stress and ionizing radiation stress. Aging shared the largest number of gene expression changes with hyperoxia. The extensive down-regulation of mitochondrial and ETC genes during aging is consistent with an aging-associated failure in mitochondrial maintenance, which may underlie the oxidative stress-like and proteotoxic stress-like responses observed during aging. Thirty five sample of RNA including Stress Controls (4 replicates), Heat Stress (3 replicates), Ionizing Radiation (4 replicates), Sugar (4 replicates), Hydrogen Peroxide (4 replicates), Young Controls (6 replicates) , Hyperoxia (6 replicates) and Old (4 replicates) adult Drosophila were analysed by Affymetrix microarrays. Stress Controls were used as controls for Heat Stress, Ionizing Radiation, Sugar and Hydrogen Peroxide samples. Young Controls were used as controls for Hyperoxia and Old samples. All flies were male progeny of a cross between Oregon-R wildtype and transgenic strain w[1118];P{w+ rtTA}(3)[E2]/ TM3. Flies lacking the balancer but bearing the transgene were used.
Project description:Chronic high sugar feeding induces obesity, hyperglycemia, and insulin resistance in flies and mammals. These phenotypes are controlled by the fat body, a liver- and adipose- like tissue in Drosophila flies. To gain insight into the mechanisms underlying the connection between diet and insulin sensitivity, we used Illumina RNA-seq to profile gene expression in fat bodies isolated from chronically high sugar fed, wandering (post-prandial) third instar wild type larvae w(L3). These data were compared to control-fed wild-type wL3 fat bodies as well as those expressing transgenic interfering RNA (i) targeting CG18362 (Mio/dChREBP) in the fat body on both diets. Female VDRC w1118, cgGAL4, UAS-Dcr2 or UAS-ChREBPi(52606), cgGAL4, UAS-Dcr2 wandering third instar larvae were fed control (0.15M) or high (0.7M) sucrose and fat bodies isolated for RNA extraction.
Project description:Chronic high sugar feeding induces obesity, hyperglycemia, and insulin resistance in flies and mammals. To gain insight into the mechanisms underlying this response, we profiled gene expression in chronically high sugar fed, wandering (post-prandial) third instar wild type larvae (L3). These data were compared to control-fed larvae as well as those (mid-L3) actively feeding for twelve hours on both diets. We used microarrays to detail the response of Drosophila larvae to high sugar-induced insulin resistance. Male Canton-S third instar larvae were fed control (0.15M) or high (1M) sucrose and selected for RNA extraction and hybridization on Affymetrix microarrays. Wandering L3 were selected as those in the top half of the vial with partial blue guts to confirm that they had stopped eating the (blue) food. Mid-L3 were selected as L2, aged overnight until early L3, then transferred to fresh control or high sucrose food for 12 more hours before selection.
Project description:dFOXO targets in adult Drosophila melanogaster females, and the effect of insulin signalling and stress on binding. The experimets determined the binding locations of dFOXO in the whole adult female fly using ChIP-chip. The protocol was validated using mock conditions: pre-immune serum or IP on chromatin from foxo null flies. The response of this binding to stress induced by treatment of flies with paraquat or by their exposure to starvation, as well as the response to an insulin-signalling-reducing genetic manipulation (over-expression of dominant negative form of the insulin receptor), was determined.
Project description:Whole fly transcript profiles of changes upon induction of dFOXO in the gut and fat body using S1106>dFOXO flies and how this response changes when the feedback to foxo is removed in the foxo null background
Project description:75 Diosophilia Roo lines, recominant inbred lines, were raised to adulthood either on conventional diet or diet supplemented with lead acetate. Whole flies were used for RNA extraction. RNA was run on Dros Genome 2 arrays. Each line also genotyped for 88 markers; Control food consisted of standard cornmeal, agar, sugar, yeast, and 250 microM NaAc (Ashburner 1989). Lead-contaminated food consisted of standard food plus 250 microM PbAc (lead exposure at this concentration has been shown to affect locomotion in adults (Hirsch et al. 2003)). Experiment Overall Design: 75 RI lines each line treated and untreated with lead acetate
Project description:Transcriptional analysis of dInR and dfoxo epistasis in Drosophila melanogaster. The experiment was performed to examine which parts of the transcriptional response to a reduction in insulin signalling in an adult female fly depend on the presence of the dfoxo transcription factor. Whole fly transcriptome was determined with flies over-expressing a dominant negative form of the insulin receptor, or the wild-type fly, in presence or absence of dfoxo.
Project description:We recently developed a fly model of pentylenetetrazol (PTZ)-induced long-term behavioral plasticity. Pharmacological validation suggests this model to be kindling-like. Hence, our model is of relevance in understanding the molecular pathogenesis of epileptogenesis as well as in screening potential antiepileptogenic agents. Vigabatrin (VGB) is an antiepileptic drug, and in the process of developing our fly model we generated gene expression profile of flies’ head secondary to treatment of the insects with VGB. Our results provide novel insights in to the drug’s mode of action. Oregon-R wild type D. melanogaster was grown in standard fly medium consisting of agar-agar, maize powder, brown sugar, dried yeast, and nipagin. Flies were cultured at 24 +/- 1ºC, 60% RH, and 12 hrs light (9 AM to 9 PM) and 12 hours dark cycle. Ten to eleven days old unmated adult males were grown in either normal food (NF) or food containing 24 mg/ml of VGB for three days. Each culture vials contained 30 flies. Flies frozen in liquid nitrogen were agitated and the heads collected using cooled sieves. Total RNA was isolated from eight pools of frozen heads, every two of which represented a single parallel set of treatment in which four vials contained NF treated control flies, and four VGB treated individuals, using TRI REAGENT (Sigma) according to the manufacturer’s protocol. Double stranded cDNA was synthesized from 10 µg of total RNA using Microarray cDNA Synthesis Kit (Roche), and the cDNA purified using Micorarray Target Purification Kit (Roche), according to the manufacturer’s protocol. Each of the four sets of NF control and VGB treated cDNA samples, belonging to the four biological replicates, was used for labeling with either Cy3 or Cy5 dyes (Amersham Biosciences) using Microarray RNA Target Synthesis Kit T7 (Roche). The labeled products were purified by Microarray Target Purification Kit (Roche). The Cy3 and Cy5 labeled two cRNA samples of each biological replicate were pooled together, precipitated, washed, air-dried, and dissolved in 18MΩ RNAase free water (Sigma). Dye swapping was accomplished by hybridizing two arrays with NF control as Cy3- and VGB treated as Cy5- labeled sample, and the rest two as the opposite, NF as Cy5- and drug treated as Cy3- labeled sample. The labeled product was mixed with hybridization solution containing hybridization buffer (DIG Easy Hyb; Roche), 10mg/ml salmon testis DNA (0.05 mg/ml final concentration, Sigma) and 10mg/ml yeast tRNA (0.05 mg/ml final concentration, Sigma). The hybridization mixture was denatured at 65ºC and applied onto cDNA microarray slides (D12Kv1, CDMC, Toronto). The slides were covered by a coverslip (ESCO, Portsmouth, USA) and hybridization was allowed to take place in hybridization chamber (Corning) at 37ºC for 16 hrs. Following hybridization, the coverslips were removed in a solution containing 1X SSC and 0.1% SDS at 50ºC, and the slides washed in 1X SSC and 0.1% SDS (three times for 15 minutes each) in a coplin jar at 50ºC with occasional swirling and then transferred to 1X SSC and washed with gentle swirling at room temperature (twice for 15 minutes each). Slides were given a final wash in 0.1X SSC for 15 minutes and then liquid was quickly removed from the slide surface by spinning at 600 rpm for 5 minutes. Slides were scanned at 10µm resolution in GenePix 4000A Microarray Scanner (Molecular Devices). The 16 bit TIFF images were preprocessed and quantified using Gene Pix Pro 6.0 software (Molecular Devices). Ratio based normalization was performed using Acuity 4.0 software (Molecular Devices). All Spots with raw intensity less then 100U and less then twice the average background was ignored during normalization. Normalized data was filtered for the selection of features before further analysis. Only those spot were selected which contained only a small percentage (<3) of saturated pixels, were not flagged bad or found absent (flags >= 0), had relatively uniform intensity and uniform background (Rgn R2 (635/532) >= 0.6) and were detectable above background (SNR >= 3). Analyzable spots in at least three of the four biological replicates performed were retrieved for downstream analysis using Significance Analysis of Microarrays (SAM 2.21, Excel Add-In, Stanford) under the conditions of one class response and 100 permutations.
Project description:We recently developed a fly model of pentylenetetrazol (PTZ)-induced long-term behavioral plasticity. Pharmacological validation suggests this model to be kindling-like. Hence, our model is of relevance in understanding the molecular pathogenesis of epileptogenesis as well as in screening potential antiepileptogenic agents. Ethosuximide (ETH) is an antiepileptic drug, and in the process of developing our fly model we generated gene expression profile of flies’ head secondary to treatment of the insects with ETH. Our results provide novel insights in to the drug’s mode of action. Oregon-R wild type D. melanogaster was grown in standard fly medium consisting of agar-agar, maize powder, brown sugar, dried yeast, and nipagin. Flies were cultured at 24+/-1ºC 60% RH, and 12 hrs light (9 AM to 9 PM) and 12 hours dark cycle. Ten to eleven days old unmated adult males were grown in either normal food (NF) or food containing 3.48 mg/ml of ETH for three days. Each culture vials contained 30 flies. Flies frozen in liquid nitrogen were agitated and the heads collected using cooled sieves. Total RNA was isolated from eight pools of frozen heads, every two of which represented a single parallel set of treatment in which four vials contained NF treated control flies, and four ETH treated individuals, using TRI REAGENT (Sigma) according to the manufacturer’s protocol. Double stranded cDNA was synthesized from 10 µg of total RNA using Microarray cDNA Synthesis Kit (Roche), and the cDNA purified using Micorarray Target Purification Kit (Roche), according to the manufacturer’s protocol. Each of the four sets of NF control and ETH treated cDNA samples, belonging to the four biological replicates, was used for labeling with either Cy3 or Cy5 dyes (Amersham Biosciences) using Microarray RNA Target Synthesis Kit T7 (Roche). The labeled products were purified by Microarray Target Purification Kit (Roche). The Cy3 and Cy5 labeled two cRNA samples of each biological replicate were pooled together, precipitated, washed, air-dried, and dissolved in 18MΩ RNAase free water (Sigma). Dye swapping was accomplished by hybridizing two arrays with NF control as Cy3- and ETH treated as Cy5- labeled sample, and the rest two as the opposite, NF as Cy5- and drug treated as Cy3- labeled sample. The labeled product was mixed with hybridization solution containing hybridization buffer (DIG Easy Hyb; Roche), 10mg/ml salmon testis DNA (0.05 mg/ml final concentration, Sigma) and 10mg/ml yeast tRNA (0.05 mg/ml final concentration, Sigma). The hybridization mixture was denatured at 65ºC and applied onto cDNA microarray slides (D12Kv1, CDMC, Toronto). The slides were covered by a coverslip (ESCO, Portsmouth, USA) and hybridization was allowed to take place in hybridization chamber (Corning) at 37ºC for 16 hrs. Following hybridization, the coverslips were removed in a solution containing 1X SSC and 0.1% SDS at 50ºC, and the slides washed in 1X SSC and 0.1% SDS (three times for 15 minutes each) in a coplin jar at 50ºC with occasional swirling and then transferred to 1X SSC and washed with gentle swirling at room temperature (twice for 15 minutes each). Slides were given a final wash in 0.1X SSC for 15 minutes and then liquid was quickly removed from the slide surface by spinning at 600 rpm for 5 minutes. Slides were scanned at 10µm resolution in GenePix 4000A Microarray Scanner (Molecular Devices). The 16 bit TIFF images were preprocessed and quantified using Gene Pix Pro 6.0 software (Molecular Devices). Ratio based normalization was performed using Acuity 4.0 software (Molecular Devices). All Spots with raw intensity less then 100U and less then twice the average background was ignored during normalization. Normalized data was filtered for the selection of features before further analysis. Only those spot were selected which contained only a small percentage (<3) of saturated pixels, were not flagged bad or found absent (flags >= 0), had relatively uniform intensity and uniform background (Rgn R2 (635/532) >= 0.6) and were detectable above background (SNR >= 3). Analyzable spots in at least three of the four biological replicates performed were retrieved for downstream analysis using Significance Analysis of Microarrays (SAM 2.21, Excel Add-In, Stanford) under the conditions of one class response and 100 permutations.
Project description:To identify genes differentially expressed in the fatbody of Drosphila melanogaster bigmax mutants, a loss-of-function allele was generated by P-element mobilization. Mutant and wildtype first instar larvae were raised on two different sources of food, control and high-sugar media. When the animals reached the wandering third instar stage, animals were sacrificed and their fat bodies dissected. Total RNA was extracted, labeled fluorescently and hybridized competitively to Agilent's 4x44K Drosophila Gene Expression Microarrays. On each array, three different samples were analyzed: 1. wildtype animals raised on control food, 2. wildtype animals raised on high-sugar food and 3. bigmax mutant animals raised on high-sugar food.