Circadian rhythms are core regulatory mechanisms that evolved to align biological functions with the Earth's rotation. These rhythms are conserved across organisms from unicellular life to multicellular species and play essential roles in metabolism, immune responses, and sleep-wake cycle. Circadian disruptions are strongly associated with various diseases. Over the past decades, genetic studies in Drosophila and mice have identified key conserved clock genes and uncovered transcription-translation feedback loops governing circadian regulation. Additionally, rhythmic neurons in the brain integrate complex neural circuits to precisely regulate physiological and behavioral rhythms. This review highlights recent advances in understanding the neuronal circuit mechanisms of rhythmic neurons in the Drosophila brain and discusses future directions for translating circadian rhythm research into chronomedicine and precision therapies.
Animals ; Circadian Rhythm/genetics* ; Neurons/physiology* ; Drosophila/physiology* ; Brain/physiology* ; Nerve Net/physiology*

OBJECTIVES: To investigate how larval feeding regimens influence development and deltamethrin resistance of Aedes albopictus to provide evidence for standardizing larval feeding protocols in studies of insecticide resistance. METHODS: Aedes albopictus larvae of a laboratory resistant strain were divided into 3 groups (n=500) and reared with high, medium, and low food availability (100, 50, or 25 mg daily for the 1st and 2nd instars, and 500 mg 250, or 125 mg daily for 3rd and 4th instars). The developmental time, pupation rate, adult emergence rate, adult body weight, and wing length were recorded in each group, and deltamethrin resistance of the mosquitoes was assessed using larval bioassays and contact tube tests for adults. RESULTS: Significant developmental differences were observed across the 3 feeding groups. Larval development time decreased as the food availability increased, and both high- and low-food groups showed reduced pupation rates (χ²=16.282, 7.440) and emergence rates (χ²=4.093, 6.977) compared to the medium-food group. Adult body weight and wing length were positively correlated with the amount of larval food intake (P<0.05). In high, medium and low food intake groups, larval LC₅₀ values for deltamethrin were 0.110, 0.072 and 0.064 mg/L, adult KDT50 values were 97.404, 68.964 and 65.005 min, and adult mosquitoe mortality rates at 24 h after deltamethrin exposure were 12%, 16% and 19%, respectively. CONCLUSIONS The feeding amount during larval stage significantly impacts the development and deltamethrin resistance of Aedes albopictus, suggesting the importance of standardization of larval nutrition for ensuring comparability of resistance test data across laboratories.
Animals ; Aedes/physiology* ; Pyrethrins/pharmacology* ; Nitriles/pharmacology* ; Larva/physiology* ; Insecticide Resistance ; Insecticides/pharmacology* ; Feeding Behavior

Sleep, an essential and evolutionarily conserved behavior, is regulated by numerous neurotransmitter systems. In mammals, glutamate serves as the wake-promoting signaling agent, whereas in Drosophila, it functions as the sleep-promoting signal. However, the precise molecular and cellular mechanisms through which glutamate promotes sleep remain elusive. Our study reveals that disruption of glutamate signaling significantly diminishes nocturnal sleep, and a neural cell-specific knockdown of the glutamate-gated chloride channel (GluClα) markedly reduces nocturnal sleep. We identified two pairs of neurons in the ventral nerve cord (VNC) that receive glutamate signaling input, and the GluClα derived from these neurons is crucial for sleep promotion. Furthermore, we demonstrated that GluClα mediates the glutamate-gated inhibitory input to these VNC neurons, thereby promoting sleep. Our findings elucidate that GluClα enhances nocturnal sleep by mediating the glutamate-gated inhibitory input to two pairs of VNC neurons, providing insights into the mechanism of sleep promotion in Drosophila.
Animals ; Sleep/physiology* ; Neurons/metabolism* ; Chloride Channels/genetics* ; Drosophila Proteins/genetics* ; Drosophila ; Glutamic Acid/metabolism* ; Animals, Genetically Modified

Introduction: Folkloric claims have surrounded essential oils, including their enhancement of learning and memory through inhalational exposure. Few studies in humans have shown a benefit in cognition, albeit incremental. However, this benefit may not be entirely attributable to the essential oil aroma but may be confounded by psychological associations. We investigated rosemary, peppermint, lemon, and coffee aromas in a learning and memory model of Drosophila melanogaster to eliminate this confounder. Methods: We screened for concentrations of the four treatments that are non-stimulatory for altered locomotory behavior in the flies. At these concentrations, we determined if they were chemoneutral (i.e., neither chemoattractant nor chemorepellent) to the flies. Learning and memory of the flies exposed to these aromas were determined using an Aversive Phototaxis Suppression (APS) assay. Results: The aromas of rosemary, peppermint, and lemon that did not elicit altered mobility in the flies were from dilute essential oil solutions that ranged from 0.2 to 0.5% v/v; whereas for the aroma in coffee, it was at a higher concentration of 7.5% m/v. At these concentrations, the aromas used were found to be chemoneutral towards the flies. We observed no improvement in both learning and memory in the four aromas tested. While a significant reduction (p < 0.05) in learning was observed when flies were treated with the aromas of rosemary, peppermint, and coffee, a significant reduction (p < 0.05) in memory was only observed in the peppermint aroma treatment. Conclusion This study demonstrated that in the absence of psychological association, the four aromas do not enhance learning and memory
Drosophila melanogaster ; Learning ; Memory ; Rosmarinus ; Mentha piperita ; Citrus ; Coffea

Background: Consumption and abuse of alcohol remains a significant cause of concern worldwide. Furthermore, there is evidence of the association between chronic alcohol use and reduced life expectancy. Objectives: To study the effects of Garcinia binucao extract (GBE) supplementation on lifespan of Drosophila melanogaster, in the presence or absence of chronic alcohol exposure. Methods: D. melanogaster was mass cultured and given GBE supplementation in high (1 mg/mL) and low (200 µg/mL) sublethal doses. D. melanogaster flies were divided into groups - with and without chronic alcohol exposure, and their respective lifespans were monitored. Results: In D. melanogaster without alcohol exposure, mean lifespan was highest in the control flies (38.15 days), followed by high-dose GBE (34.42 days), low-dose GBE (33.24 days), and DMSO (22.29 days). In D. melanogaster chronically exposed to alcohol, the longest mean lifespan was observed in flies treated with high-dose GBE (33.80 days), followed by low-dose GBE (33.63 days), the DMSO group (30.30), and the control group (29.65 days), but the differences were not statistically significant. Comparing groups with and without chronic alcohol exposure, the mean lifespan of the control group chronically exposed to alcohol significantly decreased by 9.51 days (p < 0.05). In GBE treatment groups, mean lifespan significantly decreased by 0.82 days in high-dose set-up (p < 0.05), and significantly increased by 0.39 days in the low-dose set-up (p < 0.05) upon chronic alcohol exposure. Conclusion Garcinia binucao extract supplementation ameliorated the observed reduction in lifespan of Drosophila melanogaster chronically exposed to alcohol.
Drosophila melanogaster ; Longevity

Objective: To explore the impact of health management measures for entry personnel (entry management measures) against COVID-19 on the epidemiological characteristics of imported Dengue fever in Guangdong Province from 2020 to 2022. Methods: Data of imported Dengue fever from January 1, 2016 to August 31, 2022, mosquito density surveillance from 2016 to 2021, and international airline passengers and Dengue fever annual reported cases from 2011 to 2021 in Guangdong were collected. Comparative analysis was conducted to explore changes in the epidemic characteristics of imported Dengue fever before the implementation of entry management measures (from January 1, 2016 to March 20, 2020) and after the implementation (from March 21, 2020 to August 31, 2022). Results: From March 21, 2020, to August 31, 2022, a total of 52 cases of imported Dengue fever cases were reported, with an imported risk intensity of 0.12, which were lower than those before implementation of entry management measures (1 828, 5.29). No significant differences were found in the characteristics of imported cases before and after implementation of entry management measures, including seasonality, sex, age, career, and imported countries (all P>0.05). 59.62% (31/52) of cases were found at the centralized isolation sites and 38.46% (20/52) at the entry ports. However, before implementation of entry management measures, 95.08% (1 738/1 828) of cases were found in hospitals. Among 51 cases who had provided entry dates, 82.35% (42/51) and 98.04% (50/51) of cases were found within seven days and fourteen days after entry, slightly higher than before implementation [(72.69%(362/498) and 97.59% (486/498)]. There was significant difference between the monthly mean values of Aedes mosquito larval density (Bretto index) from 2020 to 2021 and those from 2016 to 2019 (Z=2.83, P=0.005). There is a strong positive correlation between the annual international airline passengers volume in Guangdong from 2011 to 2021 and the annual imported Dengue fever cases (r=0.94, P<0.001), and a positive correlation also existed between the international passenger volume and the annual indigenous Dengue fever cases (r=0.72, P=0.013). Conclusions: In Guangdong, the entry management measures of centralized isolation for fourteen days after entry from abroad had been implemented, and most imported Dengue fever cases were found within fourteen days after entry. The risk of local transmission caused by imported cases has reduced significantly.
Animals ; Humans ; COVID-19 ; Aedes ; Epidemics ; China/epidemiology* ; Dengue/epidemiology*

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*

Females increase aggression for mating opportunities and for acquiring reproductive resources. Although the close relationship between female aggression and mating status is widely appreciated, whether and how female aggression is regulated by mating-related cues remains poorly understood. Here we report an interesting observation that Drosophila virgin females initiate high-frequency attacks toward mated females. We identify 11-cis-vaccenyl acetate (cVA), a male-derived pheromone transferred to females during mating, which promotes virgin female aggression. We subsequently reveal a cVA-responsive neural circuit consisting of four orders of neurons, including Or67d, DA1, aSP-g, and pC1 neurons, that mediate cVA-induced virgin female aggression. We also determine that aSP-g neurons release acetylcholine (ACh) to excite pC1 neurons via the nicotinic ACh receptor nAChRα7. Together, beyond revealing cVA as a mating-related inducer of virgin female aggression, our results identify a neural circuit linking the chemosensory perception of mating-related cues to aggressive behavior in Drosophila females.
Animals ; Male ; Female ; Drosophila/physiology* ; Drosophila Proteins/physiology* ; Cues ; Sexual Behavior, Animal/physiology* ; Aggression/physiology* ; Drosophila melanogaster/physiology*

Anti-reflective nanocoatings that mimic the eyes of fruit flies are biodegradable materials with great market potential for a variety of optical devices that require anti-reflective properties. Microbial expression of retinin provides a new idea for the preparation of nanocoatings under mild conditions compared to physicochemical methods. However, the current expression level of retinin, the key to anti-reflective coating, is low and difficult to meet mass production. In this study, we analyzed and screened the best expression hosts for Drosophila-derived retinin protein, and optimized its expression. Chinese hamster ovary (CHO) cells were identified as the efficient expression host of retinin, and purified retinin protein was obtained. At the same time, the preparation method of lanolin nanoemulsion was explored, and the best anti-reflective ability of the nano-coating was determined when the ratio of specific concentration of retinin protein and wax emulsion was 16:4, the pH of the nano-coating formation system was 7.0, and the temperature was 30 ℃. The enhanced antireflective ability and reduced production cost of artificial antireflective nanocoatings by determining the composition of nanocoatings and optimizing the concentration, pH and temperature of system components may facilitate future application of artificial green degradable antireflective coatings.
Animals ; Cricetinae ; CHO Cells ; Emulsions ; Cricetulus ; Drosophila ; Eye Proteins ; Drosophila Proteins

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*