Resveratrol (RES), a natural polyphenolic phytochemical, has been suggested as a putative anti-aging molecule for the prevention and treatment of Alzheimer's disease (AD) by the activation of sirtuin 1 (Sirt1/Sir2). In this study, we tested the effects of RES and Sirt1/Sir2 on sleep and courtship memory in a Drosophila model by overexpression of amyloid precursor protein (APP), whose duplications and mutations cause familial AD. We found a mild but significant transcriptional increase of Drosophila Sir2 (dSir2) by RES supplementation for up to 17 days in APP flies, but not for 7 days. RES and dSir2 almost completely reversed the sleep and memory deficits in APP flies. We further demonstrated that dSir2 acts as a sleep promotor in Drosophila neurons. Interestingly, RES increased sleep in the absence of dSir2 in dSir2-null mutants, and RES further enhanced sleep when dSir2 was either overexpressed or knocked down in APP flies. Finally, we showed that Aβ aggregates in APP flies were reduced by RES and dSir2, probably via inhibiting Drosophila β-secretase (dBACE). Our data suggest that RES rescues the APP-induced behavioral deficits and Aβ burden largely, but not exclusively, via dSir2.
Animals ; Alzheimer Disease/metabolism* ; Amyloid beta-Peptides ; Amyloid beta-Protein Precursor/metabolism* ; Drosophila/physiology* ; Drosophila Proteins/metabolism* ; Resveratrol/pharmacology* ; Sirtuin 1 ; Sleep

The gastrointestinal tract is the largest digestive organ and the largest immune organ and detoxification organ, which is vital to the health of the body. Drosophila is a classic model organism, and its gut is highly similar to mammalian gut in terms of cell composition and genetic regulation, therefore can be used as a good model for studying gut development. target of rapmaycin complex 1 (TORC1) is a key factor regulating cellular metabolism. Nprl2 inhibits TORC1 activity by reducing Rag GTPase activity. Previous studies have found that nprl2 mutated Drosophila showed aging-related phenotypes such as enlarged foregastric and reduced lifespan, which were caused by over-activation of TORC1. In order to explore the role of Rag GTPase in the developmental defects of the gut of nprl2 mutated Drosophila, we used genetic hybridization combined with immunofluorescence to study the intestinal morphology and intestinal cell composition of RagA knockdown and nprl2 mutated Drosophila. The results showed that RagA knockdown alone could induce intestinal thickening and forestomach enlargement, suggesting that RagA also plays an important role in intestinal development. Knockdown of RagA rescued the phenotype of intestinal thinning and decreased secretory cells in nprl2 mutants, suggesting that Nprl2 may regulate the differentiation and morphology of intestinal cells by acting on RagA. Knockdown of RagA did not rescue the enlarged forestomach phenotype in nprl2 mutants, suggesting that Nprl2 may regulate forestomach development and intestinal digestive function through a mechanism independent of Rag GTPase.
Animals ; Drosophila/genetics* ; Mechanistic Target of Rapamycin Complex 1/metabolism* ; Mammals/metabolism* ; Carrier Proteins ; Tumor Suppressor Proteins/metabolism* ; Drosophila Proteins/genetics*

This study aims to explore the neuroprotective mechanism of ginsenoside Re(GS-Re) on drosophila model of Parkinson's disease(PD) induced by rotenone(Rot). To be specific, Rot was used to induce PD in drosophilas. Then the drosophilas were grouped and respectively treated(GS-Re: 0.1, 0.4, 1.6 mmol·L~(-1); L-dopa: 80 μmol·L~(-1)). Life span and crawling ability of drosophilas were determined. The brain antioxidant activity [content of catalase(CAT), malondialdehyde(MDA), reactive oxygen species(ROS), superoxide dismutase(SOD)], dopamine(DA) content, and mitochondrial function [content of adenosine triphosphate(ATP), NADH:ubiquinone oxidoreductase subunit B8(NDUFB8) Ⅰ activity, succinate dehydrogenase complex, subunit B(SDHB) Ⅱ activity] were detected by enzyme-linked immunosorbent assay(ELISA). The number of DA neurons in the brains of drosophilas was measured with the immunofluorescence method. The levels of NDUFB8 Ⅰ, SDHB Ⅱ, cytochrome C(Cyt C), nuclear factor-E2-related factor 2(Nrf2), heme oxygenase-1(HO-1), B-cell lymphoma/leukemia 2(Bcl-2)/Bcl-2-assaciated X protein(Bax), and cleaved caspase-3/caspase-3 in the brain were detected by Western blot. The results showed that model group [475 μmol·L~(-1) Rot(IC_(50))] demonstrated significantly low survival rate, obvious dyskinesia, small number of neurons and low DA content in the brain, high ROS level and MDA content, low content of SOD and CAT, significantly low ATP content, NDUFB8 Ⅰ activity, and SDHB Ⅱ activity, significantly low expression of NDUFB8 Ⅰ, SDHB Ⅱ, and Bcl-2/Bax, large amount of Cyt C released from mitochondria to cytoplasm, low nuclear transfer of Nrf2, and significantly high expression of cleaved caspase-3/caspase-3 compared with the control group. GS-Re(0.1, 0.4, and 1.6 mmol·L~(-1)) significantly improved the survival rate of PD drosophilas, alleviated the dyskinesia, increased DA content, reduced the loss of DA neurons, ROS level, and MDA content in brain, improved content of SOD and CAT and antioxidant activity in brain, maintained mitochondrial homeostasis(significantly increased ATP content and activity of NDUFB8 Ⅰ and SDHB Ⅱ, significantly up-regulated expression of NDUFB8 Ⅰ, SDHB Ⅱ, and Bcl-2/Bax), significantly reduced the expression of Cyt C, increased the nuclear transfer of Nrf2, and down-regulated the expression of cleaved caspase-3/caspase-3. In conclusion, GS-Re can significantly relieve the Rot-induced cerebral neurotoxicity in drosophilas. The mechanism may be that GS-Re activates Keap1-Nrf2-ARE signaling pathway by maintaining mitochondrial homeostasis, improves antioxidant capacity of brain neurons, then inhibits mitochondria-mediated caspase-3 signaling pathway, and the apoptosis of neuronal cells, thereby exerting the neuroprotective effect.
Animals ; Reactive Oxygen Species/metabolism* ; Antioxidants/pharmacology* ; Oxidative Stress ; NF-E2-Related Factor 2/metabolism* ; Caspase 3/metabolism* ; Parkinson Disease/genetics* ; bcl-2-Associated X Protein/metabolism* ; Neuroprotective Agents/pharmacology* ; Kelch-Like ECH-Associated Protein 1/metabolism* ; Drosophila/metabolism* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Apoptosis ; Superoxide Dismutase/metabolism* ; Adenosine Triphosphate/pharmacology*

Transmembrane emp24 domain (TMED) gene is closely related to immune response, signal transduction, growth and disease development in mammals. However, only the Drosophila TMED gene has been reported on insects. We identified the TMED family genes of silkworm, Tribolium castaneum, tobacco moth and Italian bee from their genomes, and found that the TMED family gene composition patterns of one α-class, one β-class, one δ-class and several γ-classes arose in the common ancestor of pre-divergent Hymenoptera insects, while the composition of Drosophila TMED family members has evolved in a unique pattern. Insect TMED family γ-class genes have evolved rapidly, diverging into three separate subclasses, TMED6-like, TMED5-like and TMED3-like. The TMED5-like gene was lost in Hymenoptera, duplicated in the ancestors of Lepidoptera and duplicated in Drosophila. Insect TMED protein not only has typical structural characteristics of TMED, but also has obvious signal peptide. There are seven TMED genes in silkworm, distributed in six chromosomes. One of seven is single exon and others are multi-exons. The complete open reading frame (ORF) sequences of seven TMED genes of silkworm were cloned from larval tissues and registered in GenBank database. BmTMED1, BmTMED2 and BmTMED6 were expressed in all stages and tissues of the silkworm, and all genes were expressed in the 4th and 5th instar and silk gland of the silkworm. The present study revealed the composition pattern of TMED family members, their γ class differentiation and their evolutionary history, providing a basis for further studies on TMED genes in silkworm and other insects.
Animals ; Bombyx/metabolism* ; Genes, Insect/genetics* ; Moths/metabolism* ; Insecta/metabolism* ; Drosophila ; Insect Proteins/metabolism* ; Phylogeny ; Mammals/genetics*

Dopamine is the precursor of a variety of natural antioxidant compounds. In the body, dopamine acts as a neurotransmitter that regulates a variety of physiological functions of the central nervous system. Thus, dopamine is used for the clinical treatment of various types of shock. Dopamine could be produced by engineered microbes, but with low efficiency. In this study, DOPA decarboxylase gene from Sus scrofa (Ssddc) was cloned into plasmids with different copy numbers, and transformed into a previously developed L-DOPA producing strain Escherichia coli T004. The resulted strain was capable of producing dopamine from glucose directly. To further improve the production of dopamine, a sequence-based homology alignment mining (SHAM) strategy was applied to screen more efficient DOPA decarboxylases, and five DOPA decarboxylase genes were selected from 100 candidates. In shake-flask fermentation, the DOPA decarboxylase gene from Homo sapiens (Hsddc) showed the highest dopamine production (3.33 g/L), while the DOPA decarboxylase gene from Drosophila Melanogaster (Dmddc) showed the least residual L-DOPA concentration (0.02 g/L). In 5 L fed-batch fermentations, production of dopamine by the two engineered strains reached 13.3 g/L and 16.2 g/L, respectively. The residual concentrations of L-DOPA were 0.45 g/L and 0.23 g/L, respectively. Finally, the Ssddc and Dmddc genes were integrated into the genome of E. coli T004 to obtain genetically stable dopamine-producing strains. In 5 L fed-batch fermentation, 17.7 g/L of dopamine was produced, which records the highest titer reported to date.
Animals ; Dopa Decarboxylase/genetics* ; Dopamine/biosynthesis* ; Drosophila melanogaster/genetics* ; Escherichia coli/metabolism* ; Humans ; Metabolic Engineering

In most insects, polyunsaturated fatty acids (PUFAs) are mainly polyunsaturated fatty acids with a carbon-chain length less than 18 carbon atoms, hardly any long-chain polyunsaturated fatty acids such as C20 and C22 that are more valuable and bioactive. This study, by using Drosophila melanogaster (Fruit fly) as a model organism, optimized the Δ6-fatty acid elongase enzyme Elovl5 gene from mice and transferred it to fruit flies for expression. Vectors containing Elovl5 gene were successfully injected into drosophila embryo through the microscopic injection. There were enhanced green fluorescent proteins expressed in the whole developmental stage of Drosophila be means of fluorescence microscope. At the same time, expression of Elovl5 gene significantly contributed to the transformation of fruit flies C18-polyunsaturated fatty acids in the body towards the biosynthesis of longer-chain polyunsaturated fatty acids. The transgenic fruit fly model rich in long-chain polyunsaturated fatty acids such as C20 and C22 were obtained, providing a basis for further research on biosynthesis of polyunsaturated fatty acids in fruit flies.
Acetyltransferases/genetics* ; Animals ; Drosophila melanogaster/genetics* ; Fatty Acid Elongases/metabolism* ; Fatty Acids/genetics* ; Gene Transfer Techniques ; Mice

Animals choose among sleep, courtship, and feeding behaviors based on the integration of both external sensory cues and internal states; such choices are essential for survival and reproduction. These competing behaviors are closely related and controlled by distinct neural circuits, but whether they are also regulated by shared neural nodes is unclear. Here, we investigated how a set of male-specific P1 neurons controls sleep, courtship, and feeding behaviors in Drosophila males. We found that mild activation of P1 neurons was sufficient to affect sleep, but not courtship or feeding, while stronger activation of P1 neurons labeled by four out of five independent drivers induced courtship, but only the driver that targeted the largest number of P1 neurons affected feeding. These results reveal a common neural node that affects sleep, courtship, and feeding in a threshold-dependent manner, and provide insights into how competing behaviors can be regulated by a shared neural node.
Animals ; Animals, Genetically Modified ; Brain ; cytology ; Courtship ; Drosophila ; Drosophila Proteins ; genetics ; metabolism ; Feeding Behavior ; physiology ; Locomotion ; Male ; Neural Inhibition ; physiology ; Neural Pathways ; physiology ; Neurons ; physiology ; Sex Factors ; Sleep ; physiology

Drosophila dEAAT2, a member of the excitatory amino-acid transporter (EAAT) family, has been described as mediating the high-affinity transport of taurine, which is a free amino-acid abundant in both insects and mammals. However, the role of taurine and its transporter in hearing is not clear. Here, we report that dEAAT2 is required for the larval startle response to sound stimuli. dEAAT2 was found to be enriched in the distal region of chordotonal neurons where sound transduction occurs. The Ca imaging and electrophysiological results showed that disrupted dEAAT2 expression significantly reduced the response of chordotonal neurons to sound. More importantly, expressing dEAAT2 in the chordotonal neurons rescued these mutant phenotypes. Taken together, these findings indicate a critical role for Drosophila dEAAT2 in sound transduction by chordotonal neurons.
Acoustic Stimulation ; Action Potentials ; genetics ; Animals ; Animals, Genetically Modified ; Auditory Pathways ; physiology ; Calcium ; metabolism ; Drosophila ; genetics ; Drosophila Proteins ; genetics ; metabolism ; Excitatory Amino Acid Transporter 2 ; genetics ; metabolism ; Hearing ; genetics ; Larva ; Luminescent Proteins ; genetics ; metabolism ; Mutation ; genetics ; Nervous System ; cytology ; Neurons ; metabolism

Animals always seek rewards and the related neural basis has been well studied. However, what happens when animals fail to get a reward is largely unknown, although this is commonly seen in behaviors such as predation. Here, we set up a behavioral model of repeated failure in reward pursuit (RFRP) in Drosophila larvae. In this model, the larvae were repeatedly prevented from reaching attractants such as yeast and butyl acetate, before finally abandoning further attempts. After giving up, they usually showed a decreased locomotor speed and impaired performance in light avoidance and sugar preference, which were named as phenotypes of RFRP states. In larvae that had developed RFRP phenotypes, the octopamine concentration was greatly elevated, while tβh mutants devoid of octopamine were less likely to develop RFRP phenotypes, and octopamine feeding efficiently restored such defects. By down-regulating tβh in different groups of neurons and imaging neuronal activity, neurons that regulated the development of RFRP states and the behavioral exhibition of RFRP phenotypes were mapped to a small subgroup of non-glutamatergic and glutamatergic octopaminergic neurons in the central larval brain. Our results establish a model for investigating the effect of depriving an expected reward in Drosophila and provide a simplified framework for the associated neural basis.
Acetates ; pharmacology ; Animals ; Animals, Genetically Modified ; Avoidance Learning ; physiology ; Biogenic Amines ; metabolism ; Conditioning, Operant ; physiology ; Drosophila ; physiology ; Drosophila Proteins ; genetics ; metabolism ; Feeding Behavior ; drug effects ; physiology ; Instinct ; Larva ; physiology ; Locomotion ; drug effects ; genetics ; Nervous System ; cytology ; Neurons ; physiology ; Octopamine ; metabolism ; RNA Interference ; physiology ; Reward ; Statistics, Nonparametric ; Transcription Factors ; genetics ; metabolism

Animals ; Codon, Nonsense ; Disease ; genetics ; Drosophila ; genetics ; metabolism ; Drosophila Proteins ; genetics ; Humans ; Pseudogenes ; Receptors, Odorant ; genetics