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*

Animals ; Drosophila Proteins ; genetics ; metabolism ; Drosophila melanogaster ; Memory ; physiology ; Mushroom Bodies ; cytology ; metabolism ; Proteins ; genetics ; metabolism

The choice of females to accept or reject male courtship is a critical decision for animal reproduction. Serotonin (5-hydroxytryptamine; 5-HT) has been found to regulate sexual behavior in many species, but it is unclear how 5-HT and its receptors function to regulate different aspects of sexual behavior. Here we used Drosophila melanogaster as the model animal to investigate how 5-HT and its receptors modulate female sexual receptivity. We found that knockout of tryptophan hydroxylase (Trh), which is involved in the biosynthesis of 5-HT, severely reduced virgin female receptivity without affecting post-mating behaviors. We identified a subset of sexually dimorphic Trh neurons that co-expressed fruitless (fru), in which the activity was correlated with sexual receptivity in females. We also found that 5-HT_1A and 5-HT₇ receptors regulate virgin female receptivity. Our findings demonstrate how 5-HT functions in sexually dimorphic neurons to promote virgin female receptivity through two of its receptors.
Animals ; Male ; Female ; Drosophila/physiology* ; Drosophila melanogaster/physiology* ; Serotonin ; Drosophila Proteins/physiology* ; Sexual Behavior, Animal/physiology* ; Transcription Factors ; Nerve Tissue Proteins

It is far from understood why we forget things that are known to us seconds ago. Emerging evidence emphasizes that small G protein Rac could be a key to understanding this type of rapid early memory forgetting. This current perspective article will first review these studies and then discuss their implications for the internal processes underlying forgetting.
Animals ; Drosophila Proteins ; physiology ; Drosophila melanogaster ; physiology ; Humans ; Memory ; physiology ; Oxidation-Reduction ; Retention (Psychology) ; Signal Transduction ; rac GTP-Binding Proteins ; physiology

The mushroom body (MB), a bilateral brain structure possessing about 2000-2500 neurons per hemisphere, plays a central role in olfactory learning and memory in Drosophila melanogaster. Extensive studies have demonstrated that three major types of MB neurons (α/β, α'/β' and Γ) exhibit distinct functions in memory processing, including the critical role of approximately 1000 MB α/β neurons in retrieving long-term memory. Inspired by recent findings that MB α/β neurons can be further divided into three subdivisions (surface, posterior and core) and wherein the α/β core neurons play an permissive role in long-term memory consolidation, we examined the functional differences of all the three morphological subdivisions of MB α/β by temporally precise manipulation of their synaptic outputs during long-term memory retrieval. We found the normal neurotransmission from a combination of MB α/β surface and posterior neurons is necessary for retrieving both aversive and appetitive long-term memory, whereas output from MB α/β posterior or core subdivision alone is dispensable. These results imply a specific requirement of about 500 MB α/β neurons in supporting long-term memory retrieval and a further functional partitioning for memory processing within the MB α/β region.
Adenylyl Cyclases ; metabolism ; Animals ; Drosophila Proteins ; metabolism ; Drosophila melanogaster ; cytology ; metabolism ; physiology ; Memory, Long-Term ; physiology ; Mushroom Bodies ; cytology ; physiology ; Neurons ; cytology ; metabolism ; Synapses ; metabolism ; Transcription Factors ; metabolism

Alzheimer's disease (AD) pathogenesis is characterized by senile plaques in the brain and evidence of oxidative damage. Oxidative stress may precede plaque formation in AD; however, the link between oxidative damage and plaque formation remains unknown. Presenilins are transmembrane proteins in which mutations lead to accelerated plaque formation and early-onset familial Alzheimer's disease. Presenilins physically interact with two antioxidant enzymes thiol-specific antioxidant (TSA) and proliferation-associated gene (PAG) of the peroxiredoxin family. The functional consequences of these interactions are unclear. In the current study we expressed a presenilin transgene in Drosophila wing and sensory organ precursors of the fly. This caused phenotypes typical of Notch signaling loss-of-function mutations. We found that while expression of TSA or PAG alone produced no phenotype, co-expression of TSA and PAG with presenilin led to an enhanced Notch loss-of-function phenotype. This phenotype was more severe and more penetrant than that caused by the expression of Psn alone. In order to determine whether these phenotypes were indeed affecting Notch signaling, this experiment was performed in a genetic background carrying an activated Notch (Abruptex) allele. The phenotypes were almost completely rescued by this activated Notch allele. These results link peroxiredoxins with the in vivo function of Presenilin, which ultimately connects two key pathogenetic mechanisms in AD, namely, antioxidant activity and plaque formation, and raises the possibility of a role for peroxiredoxin family members in Alzheimer's pathogenesis.
Amino Acid Sequence ; Animals ; Drosophila ; metabolism ; physiology ; Drosophila Proteins ; metabolism ; Molecular Sequence Data ; Peroxiredoxins ; chemistry ; genetics ; metabolism ; Presenilins ; chemistry ; metabolism ; Receptors, Notch ; metabolism ; Sequence Alignment ; Signal Transduction

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 fruit fly, Drosophila melanogaster, is able to discriminate visual landmarks and form visual long-term memory in a flight simulator. Studies focused on the molecular mechanism of long-term memory have shown that memory formation requires mRNA transcription and protein synthesis. However, little is known about the molecular mechanisms underlying the visual learning paradigm. The present study demonstrated that both spaced training procedure (STP) and consecutive training procedure (CTP) would induce long-term memory at 12 hour after training, and STP caused significantly higher 12-h memory scores compared with CTP. Label-free quantification of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and microarray were utilized to analyze proteomic and transcriptomic differences between the STP and CTP groups. Proteomic analysis revealed 30 up-regulated and 27 down-regulated proteins; Transcriptomic analysis revealed 145 up-regulated and 129 down-regulated genes. Among them, five candidate genes were verified by quantitative PCR, which revealed results similar to microarray. These results provide insight into the molecular components influencing visual long-term memory and facilitate further studies on the roles of identified genes in memory formation.
Animals ; Conditioning (Psychology) ; physiology ; Drosophila Proteins ; genetics ; metabolism ; Drosophila melanogaster ; genetics ; metabolism ; physiology ; Flight, Animal ; physiology ; Gene Expression Profiling ; methods ; Memory ; physiology ; Oligonucleotide Array Sequence Analysis ; Proteomics ; methods ; Time Factors ; Vision, Ocular ; physiology

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

Animals ; Cell Nucleus ; enzymology ; Drosophila Proteins ; genetics ; metabolism ; Drosophila melanogaster ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Long-Term Potentiation ; physiology ; MAP Kinase Signaling System ; physiology ; Memory Consolidation ; physiology ; Neurons ; cytology ; enzymology