Project description:The sensation of hunger after a period of fasting and the sensation of satiety after eating is crucial to behavioral regulation of food intake, but the biological mechanisms regulating these sensations are incompletely understood. We studied the behavioral and physiological adaptation to fasting in the vinegar fly (Drosophila melanogaster). Here we show that flies demonstrated increased behavioral attraction to food odor when food-deprived with no corresponding increase in sensitivity in the peripheral olfactory system. Flies increased their food intake transiently in the post-fasted state, but returned to a stable baseline feeding level within 24 hr after return to food. This modulation in feeding was accompanied by a significant increase in the size of the crop organ of the digestive system, suggesting that fasted flies responded both by increasing their food intake and storing reserve food in their crop. The post-fasting feeding response was observed in both male and female flies of diverse genetic backgrounds. Expression profiling of head, body, and chemosensory tissues by microarray analysis revealed several hundred genes that are regulated by feeding state, including 247 genes in the fly head. We performed RNA interference-mediated knockdown of, takeout, one of the genes strongly downregulated by fasting in multiple tissues. When takeout was knocked down in all neurons the post-fasting feeding response was abolished. These observations suggest that a coordinated transcriptional response to internal physiological state may regulate both ingestive behaviors and chemosensory perception of food
Project description:The sensation of hunger after a period of fasting and the sensation of satiety after eating is crucial to behavioral regulation of food intake, but the biological mechanisms regulating these sensations are incompletely understood. We studied the behavioral and physiological adaptation to fasting in the vinegar fly (Drosophila melanogaster). Here we show that flies demonstrated increased behavioral attraction to food odor when food-deprived with no corresponding increase in sensitivity in the peripheral olfactory system. Flies increased their food intake transiently in the post-fasted state, but returned to a stable baseline feeding level within 24 hr after return to food. This modulation in feeding was accompanied by a significant increase in the size of the crop organ of the digestive system, suggesting that fasted flies responded both by increasing their food intake and storing reserve food in their crop. The post-fasting feeding response was observed in both male and female flies of diverse genetic backgrounds. Expression profiling of head, body, and chemosensory tissues by microarray analysis revealed several hundred genes that are regulated by feeding state, including 247 genes in the fly head. We performed RNA interference-mediated knockdown of, takeout, one of the genes strongly downregulated by fasting in multiple tissues. When takeout was knocked down in all neurons the post-fasting feeding response was abolished. These observations suggest that a coordinated transcriptional response to internal physiological state may regulate both ingestive behaviors and chemosensory perception of food 6 Pool of flies were used for this experiment. For each pool, samples were taken at 0,24 and 48h and separated in each body part. 56 samples were used for the analysis.
Project description:This project’s aim was to compare the transcriptional profiles of olfactory sensory neurons in Drosophila melanogaster in order to identify novel genes that specify neuron-specific functions/phenotypes or may otherwise be involved in the development of the olfactory system. The isolation of sufficient numbers of intact olfactory sensory neurons (OSN) from the antenna of Drosophila melanogaster has so far limited single-cell transcriptomic approaches being applied to the adult fly antenna. Targeted DamID (TaDa) provides an alternative approach for profiling transcriptional activity in a cell-specific manor that bypasses the need for isolating OSN. Using the Gal4/UAS system, we applied TaDa to seven OSN populations and compared differences in Pol II occupancy for genes across these datasets.
Project description:The National Institute on Alcohol Abuse and Alcoholism has estimated that approximately 14 million people in the United States suffer from alcoholism. Alcohol sensitivity, the development of tolerance to alcohol and susceptibility to addiction vary in the population. Whereas environmental factors, such as stress and social experience, contribute to individual variation in sensitivity to chronic alcohol consumption, genetic factors have also been implicated. However, genetic polymorphisms that predispose to alcoholism remain largely unknown due to extensive genetic and environmental variation in human populations. Drosophila, however, allows studies on genetically identical individuals in controlled environments. Although addiction to alcohol has not been demonstrated in Drosophila, flies show responses to alcohol exposure that resemble human intoxication, including hyperactivity, loss of postural control, sedation, and exposure-dependent development of tolerance. We assessed whole-genome transcriptional responses following alcohol exposure and demonstrate immediate down-regulation of olfactory sensitivity and, concomitant with development of tolerance, altered transcription of enzymes associated with fatty acid biosynthesis. Our results identify key enzymes in conserved metabolic pathways that may contribute to human alcohol sensitivity. Keywords: Drosophila, model system, alcohol sensitivity, tolerance
Project description:Even though proteins are produced from mRNA, the correlation between mRNA levels and protein abundances is moderate in most studies, occasionally attributed to complex post-transcriptional regulation. To address this, we generated a paired transcriptome/proteome time course dataset with 14 time points during Drosophila embryogenesis. Despite a limited mRNA-protein correlation (ρ = 0.54), mathematical models describing protein translation and degradation explain 84% of protein time-courses based on the measured mRNA dynamics without assuming complex post-transcriptional regulation, and allow for classification of most proteins into four distinct regulatory scenarios. By performing an in-depth characterization of the putatively post-transcriptionally regulated genes, we postulated that the RNA-binding protein Hrb98DE is involved in post-transcriptional control of sugar metabolism in early embryogenesis and partially validated this hypothesis using Hrb98DE knockdown. In summary, we present a systems biology framework for the identification of post-transcriptional gene regulation for large-scale time-resolved transcriptome and proteome data.