RESUMO
Seminal fluid is rich in sugars, but their role beyond supporting sperm motility is unknown. In this study, we found Drosophila melanogaster males transfer a substantial amount of a phospho-galactoside to females during mating, but only half as much when undernourished. This seminal substance, which we named venerose, induces an increase in germline stem cells (GSCs) and promotes sperm storage in females, especially undernourished ones. Venerose enters the hemolymph and directly activates nutrient-sensing Dh44+ neurons in the brain. Food deprivation directs the nutrient-sensing neurons to secrete more of the neuropeptide Dh44 in response to infused venerose. The secreted Dh44 then enhances the local niche signal, stimulating GSC proliferation. It also extends the retention of ejaculate by females, resulting in greater venerose absorption and increased sperm storage. In this study, we uncovered the role of a sugar-like seminal substance produced by males that coordinates reproductive responses to nutritional challenges in females.
Assuntos
Drosophila melanogaster , Reprodução , Comportamento Sexual Animal , Animais , Masculino , Feminino , Drosophila melanogaster/fisiologia , Drosophila melanogaster/metabolismo , Comportamento Sexual Animal/fisiologia , Reprodução/fisiologia , Espermatozoides/metabolismo , Espermatozoides/fisiologia , Sêmen/metabolismo , Sêmen/química , Proteínas de Drosophila/metabolismo , Neurônios/metabolismo , Neurônios/fisiologia , Açúcares/metabolismo , Neuropeptídeos/metabolismo , Estresse Fisiológico , Hemolinfa/metabolismo , Encéfalo/metabolismo , Motilidade dos Espermatozoides/fisiologiaRESUMO
Many animals use visual information to navigate1-4, but how such information is encoded and integrated by the navigation system remains incompletely understood. In Drosophila melanogaster, EPG neurons in the central complex compute the heading direction5 by integrating visual input from ER neurons6-12, which are part of the anterior visual pathway (AVP)10,13-16. Here we densely reconstruct all neurons in the AVP using electron-microscopy data17. The AVP comprises four neuropils, sequentially linked by three major classes of neurons: MeTu neurons10,14,15, which connect the medulla in the optic lobe to the small unit of the anterior optic tubercle (AOTUsu) in the central brain; TuBu neurons9,16, which connect the AOTUsu to the bulb neuropil; and ER neurons6-12, which connect the bulb to the EPG neurons. On the basis of morphologies, connectivity between neural classes and the locations of synapses, we identify distinct information channels that originate from four types of MeTu neurons, and we further divide these into ten subtypes according to the presynaptic connections in the medulla and the postsynaptic connections in the AOTUsu. Using the connectivity of the entire AVP and the dendritic fields of the MeTu neurons in the optic lobes, we infer potential visual features and the visual area from which any ER neuron receives input. We confirm some of these predictions physiologically. These results provide a strong foundation for understanding how distinct sensory features can be extracted and transformed across multiple processing stages to construct higher-order cognitive representations.
Assuntos
Conectoma , Drosophila melanogaster , Neurônios , Neurópilo , Navegação Espacial , Sinapses , Vias Visuais , Animais , Drosophila melanogaster/fisiologia , Drosophila melanogaster/citologia , Vias Visuais/fisiologia , Navegação Espacial/fisiologia , Neurônios/fisiologia , Neurópilo/citologia , Masculino , Feminino , Lobo Óptico de Animais não Mamíferos/citologia , Microscopia EletrônicaRESUMO
The recent assembly of the adult Drosophila melanogaster central brain connectome, containing more than 125,000 neurons and 50 million synaptic connections, provides a template for examining sensory processing throughout the brain1,2. Here we create a leaky integrate-and-fire computational model of the entire Drosophila brain, on the basis of neural connectivity and neurotransmitter identity3, to study circuit properties of feeding and grooming behaviours. We show that activation of sugar-sensing or water-sensing gustatory neurons in the computational model accurately predicts neurons that respond to tastes and are required for feeding initiation4. In addition, using the model to activate neurons in the feeding region of the Drosophila brain predicts those that elicit motor neuron firing5-a testable hypothesis that we validate by optogenetic activation and behavioural studies. Activating different classes of gustatory neurons in the model makes accurate predictions of how several taste modalities interact, providing circuit-level insight into aversive and appetitive taste processing. Additionally, we applied this model to mechanosensory circuits and found that computational activation of mechanosensory neurons predicts activation of a small set of neurons comprising the antennal grooming circuit, and accurately describes the circuit response upon activation of different mechanosensory subtypes6-10. Our results demonstrate that modelling brain circuits using only synapse-level connectivity and predicted neurotransmitter identity generates experimentally testable hypotheses and can describe complete sensorimotor transformations.
Assuntos
Encéfalo , Drosophila melanogaster , Modelos Neurológicos , Paladar , Animais , Drosophila melanogaster/fisiologia , Encéfalo/fisiologia , Encéfalo/citologia , Paladar/fisiologia , Comportamento Alimentar/fisiologia , Asseio Animal/fisiologia , Sinapses/fisiologia , Simulação por Computador , Optogenética , Neurônios Motores/fisiologia , Feminino , Masculino , ConectomaRESUMO
Walking is a complex motor programme involving coordinated and distributed activity across the brain and the spinal cord. Halting appropriately at the correct time is a critical component of walking control. Despite progress in identifying neurons driving halting1-6, the underlying neural circuit mechanisms responsible for overruling the competing walking state remain unclear. Here, using connectome-informed models7-9 and functional studies, we explain two fundamental mechanisms by which Drosophila implement context-appropriate halting. The first mechanism ('walk-OFF') relies on GABAergic neurons that inhibit specific descending walking commands in the brain, whereas the second mechanism ('brake') relies on excitatory cholinergic neurons in the nerve cord that lead to an active arrest of stepping movements. We show that two neurons that deploy the walk-OFF mechanism inhibit distinct populations of walking-promotion neurons, leading to differential halting of forward walking or turning. The brake neurons, by constrast, override all walking commands by simultaneously inhibiting descending walking-promotion neurons and increasing the resistance at the leg joints. We characterized two behavioural contexts in which the distinct halting mechanisms were used by the animal in a mutually exclusive manner: the walk-OFF mechanism was engaged for halting during feeding and the brake mechanism was engaged for halting and stability during grooming.
Assuntos
Neurônios Colinérgicos , Drosophila melanogaster , Neurônios GABAérgicos , Caminhada , Animais , Caminhada/fisiologia , Drosophila melanogaster/fisiologia , Neurônios GABAérgicos/fisiologia , Neurônios GABAérgicos/metabolismo , Feminino , Neurônios Colinérgicos/fisiologia , Masculino , Conectoma , Encéfalo/fisiologia , Encéfalo/citologia , Vias Neurais/fisiologia , Comportamento Alimentar/fisiologia , Modelos Neurológicos , Medula Espinal/fisiologia , Medula Espinal/citologiaRESUMO
The fruit fly Drosophila melanogaster has emerged as a key model organism in neuroscience, in large part due to the concentration of collaboratively generated molecular, genetic and digital resources available for it. Here we complement the approximately 140,000 neuron FlyWire whole-brain connectome1 with a systematic and hierarchical annotation of neuronal classes, cell types and developmental units (hemilineages). Of 8,453 annotated cell types, 3,643 were previously proposed in the partial hemibrain connectome2, and 4,581 are new types, mostly from brain regions outside the hemibrain subvolume. Although nearly all hemibrain neurons could be matched morphologically in FlyWire, about one-third of cell types proposed for the hemibrain could not be reliably reidentified. We therefore propose a new definition of cell type as groups of cells that are each quantitatively more similar to cells in a different brain than to any other cell in the same brain, and we validate this definition through joint analysis of FlyWire and hemibrain connectomes. Further analysis defined simple heuristics for the reliability of connections between brains, revealed broad stereotypy and occasional variability in neuron count and connectivity, and provided evidence for functional homeostasis in the mushroom body through adjustments of the absolute amount of excitatory input while maintaining the excitation/inhibition ratio. Our work defines a consensus cell type atlas for the fly brain and provides both an intellectual framework and open-source toolchain for brain-scale comparative connectomics.
Assuntos
Encéfalo , Conectoma , Drosophila melanogaster , Neurônios , Animais , Drosophila melanogaster/citologia , Drosophila melanogaster/fisiologia , Neurônios/citologia , Neurônios/fisiologia , Neurônios/classificação , Encéfalo/citologia , Encéfalo/fisiologia , Reprodutibilidade dos Testes , Masculino , Curadoria de Dados , Feminino , Contagem de Células , Corpos Pedunculados/citologia , Corpos Pedunculados/fisiologiaRESUMO
A goal of neuroscience is to obtain a causal model of the nervous system. The recently reported whole-brain fly connectome1-3 specifies the synaptic paths by which neurons can affect each other, but not how strongly they do affect each other in vivo. To overcome this limitation, we introduce a combined experimental and statistical strategy for efficiently learning a causal model of the fly brain, which we refer to as the 'effectome'. Specifically, we propose an estimator for a linear dynamical model of the fly brain that uses stochastic optogenetic perturbation data to estimate causal effects and the connectome as a prior to greatly improve estimation efficiency. We validate our estimator in connectome-based linear simulations and show that it recovers a linear approximation to the nonlinear dynamics of more biophysically realistic simulations. We then analyse the connectome to propose circuits that dominate the dynamics of the fly nervous system. We discover that the dominant circuits involve only relatively small populations of neurons-thus, neuron-level imaging, stimulation and identification are feasible. This approach also re-discovers known circuits and generates testable hypotheses about their dynamics. Overall, we provide evidence that fly whole-brain dynamics are generated by a large collection of small circuits that operate largely independently of each other. This implies that a causal model of a brain can be feasibly obtained in the fly.
Assuntos
Encéfalo , Conectoma , Drosophila melanogaster , Modelos Neurológicos , Neurônios , Animais , Encéfalo/fisiologia , Drosophila melanogaster/fisiologia , Neurônios/fisiologia , Optogenética , Modelos Lineares , Masculino , Feminino , Processos Estocásticos , Reprodutibilidade dos TestesRESUMO
As connectomics advances, it will become commonplace to know far more about the structure of a nervous system than about its function. The starting point for many investigations will become neuronal wiring diagrams, which will be interpreted to make theoretical predictions about function. Here I demonstrate this emerging approach with the Drosophila optic lobe, analysing its structure to predict that three Dm3 (refs. 1-4) and three TmY (refs. 2,4) cell types are part of a circuit that serves the function of form vision. Receptive fields are predicted from connectivity, and suggest that the cell types encode the local orientation of a visual stimulus. Extraclassical5,6 receptive fields are also predicted, with implications for robust orientation tuning7, position invariance8,9 and completion of noisy or illusory contours10,11. The TmY types synapse onto neurons that project from the optic lobe to the central brain12,13, which are conjectured to compute conjunctions and disjunctions of oriented features. My predictions can be tested through neurophysiology, which would constrain the parameters and biophysical mechanisms in neural network models of fly vision14.
Assuntos
Drosophila melanogaster , Modelos Neurológicos , Neurônios , Lobo Óptico de Animais não Mamíferos , Animais , Lobo Óptico de Animais não Mamíferos/citologia , Lobo Óptico de Animais não Mamíferos/fisiologia , Drosophila melanogaster/fisiologia , Drosophila melanogaster/citologia , Neurônios/fisiologia , Visão Ocular/fisiologia , Vias Visuais/fisiologia , Sinapses/fisiologia , Orientação/fisiologiaRESUMO
Connections between neurons can be mapped by acquiring and analysing electron microscopic brain images. In recent years, this approach has been applied to chunks of brains to reconstruct local connectivity maps that are highly informative1-6, but nevertheless inadequate for understanding brain function more globally. Here we present a neuronal wiring diagram of a whole brain containing 5 × 107 chemical synapses7 between 139,255 neurons reconstructed from an adult female Drosophila melanogaster8,9. The resource also incorporates annotations of cell classes and types, nerves, hemilineages and predictions of neurotransmitter identities10-12. Data products are available for download, programmatic access and interactive browsing and have been made interoperable with other fly data resources. We derive a projectome-a map of projections between regions-from the connectome and report on tracing of synaptic pathways and the analysis of information flow from inputs (sensory and ascending neurons) to outputs (motor, endocrine and descending neurons) across both hemispheres and between the central brain and the optic lobes. Tracing from a subset of photoreceptors to descending motor pathways illustrates how structure can uncover putative circuit mechanisms underlying sensorimotor behaviours. The technologies and open ecosystem reported here set the stage for future large-scale connectome projects in other species.
Assuntos
Encéfalo , Conectoma , Drosophila melanogaster , Neurônios , Sinapses , Animais , Drosophila melanogaster/fisiologia , Drosophila melanogaster/citologia , Feminino , Encéfalo/citologia , Encéfalo/fisiologia , Neurônios/fisiologia , Neurônios/citologia , Vias Neurais/fisiologia , Vias Neurais/citologia , Neurotransmissores/metabolismo , Lobo Óptico de Animais não Mamíferos/citologia , Lobo Óptico de Animais não Mamíferos/fisiologia , Vias Eferentes/fisiologia , Vias Eferentes/citologia , Células Fotorreceptoras de Invertebrados/fisiologia , Células Fotorreceptoras de Invertebrados/citologiaRESUMO
A catalogue of neuronal cell types has often been called a 'parts list' of the brain1, and regarded as a prerequisite for understanding brain function2,3. In the optic lobe of Drosophila, rules of connectivity between cell types have already proven to be essential for understanding fly vision4,5. Here we analyse the fly connectome to complete the list of cell types intrinsic to the optic lobe, as well as the rules governing their connectivity. Most new cell types contain 10 to 100 cells, and integrate information over medium distances in the visual field. Some existing type families (Tm, Li, and LPi)6-10 at least double in number of types. A new serpentine medulla (Sm) interneuron family contains more types than any other. Three families of cross-neuropil types are revealed. The consistency of types is demonstrated by analysing the distances in high-dimensional feature space, and is further validated by algorithms that select small subsets of discriminative features. We use connectivity to hypothesize about the functional roles of cell types in motion, object and colour vision. Connectivity with 'boundary types' that straddle the optic lobe and central brain is also quantified. We showcase the advantages of connectomic cell typing: complete and unbiased sampling, a rich array of features based on connectivity and reduction of the connectome to a substantially simpler wiring diagram of cell types, with immediate relevance for brain function and development.
Assuntos
Conectoma , Drosophila melanogaster , Neurônios , Lobo Óptico de Animais não Mamíferos , Vias Visuais , Animais , Lobo Óptico de Animais não Mamíferos/citologia , Drosophila melanogaster/citologia , Drosophila melanogaster/fisiologia , Vias Visuais/fisiologia , Neurônios/fisiologia , Neurônios/citologia , Interneurônios/fisiologia , Interneurônios/citologia , Feminino , Visão de Cores/fisiologia , Neurópilo/citologia , Neurópilo/fisiologia , Percepção de Movimento/fisiologia , Masculino , Algoritmos , Modelos Neurológicos , Campos Visuais/fisiologiaRESUMO
Brains comprise complex networks of neurons and connections, similar to the nodes and edges of artificial networks. Network analysis applied to the wiring diagrams of brains can offer insights into how they support computations and regulate the flow of information underlying perception and behaviour. The completion of the first whole-brain connectome of an adult fly, containing over 130,000 neurons and millions of synaptic connections1-3, offers an opportunity to analyse the statistical properties and topological features of a complete brain. Here we computed the prevalence of two- and three-node motifs, examined their strengths, related this information to both neurotransmitter composition and cell type annotations4,5, and compared these metrics with wiring diagrams of other animals. We found that the network of the fly brain displays rich-club organization, with a large population (30% of the connectome) of highly connected neurons. We identified subsets of rich-club neurons that may serve as integrators or broadcasters of signals. Finally, we examined subnetworks based on 78 anatomically defined brain regions or neuropils. These data products are shared within the FlyWire Codex ( https://codex.flywire.ai ) and should serve as a foundation for models and experiments exploring the relationship between neural activity and anatomical structure.
Assuntos
Encéfalo , Conectoma , Drosophila melanogaster , Neurônios , Animais , Encéfalo/fisiologia , Encéfalo/citologia , Encéfalo/anatomia & histologia , Drosophila melanogaster/fisiologia , Drosophila melanogaster/anatomia & histologia , Neurônios/fisiologia , Rede Nervosa/fisiologia , Rede Nervosa/anatomia & histologia , Rede Nervosa/citologia , Feminino , Masculino , Neurópilo/fisiologia , Neurópilo/citologia , Vias Neurais/fisiologia , Modelos NeurológicosRESUMO
A new study exploits genetic approaches available in Drosophila to record the neural activity within the specialized mechanosensory fields of halteres, the unique equilibrium organs of flies. The results challenge the traditional explanation for how these rapidly oscillating structures encode angular velocity during flight.
Assuntos
Voo Animal , Animais , Voo Animal/fisiologia , Drosophila/fisiologia , Drosophila/genética , Mecanorreceptores/fisiologia , Drosophila melanogaster/fisiologia , Drosophila melanogaster/genética , Fenômenos BiomecânicosRESUMO
In birds and insects, the female uptakes sperm for a specific duration post-copulation known as the ejaculate holding period (EHP) before expelling unused sperm and the mating plug through sperm ejection. In this study, we found that Drosophila melanogaster females shortens the EHP when incubated with males or mated females shortly after the first mating. This phenomenon, which we termed male-induced EHP shortening (MIES), requires Or47b+ olfactory and ppk23+ gustatory neurons, activated by 2-methyltetracosane and 7-tricosene, respectively. These odorants raise cAMP levels in pC1 neurons, responsible for processing male courtship cues and regulating female mating receptivity. Elevated cAMP levels in pC1 neurons reduce EHP and reinstate their responsiveness to male courtship cues, promoting re-mating with faster sperm ejection. This study established MIES as a genetically tractable model of sexual plasticity with a conserved neural mechanism.
Assuntos
Drosophila melanogaster , Feromônios , Comportamento Sexual Animal , Animais , Feminino , Masculino , Drosophila melanogaster/fisiologia , Comportamento Sexual Animal/fisiologia , Feromônios/metabolismo , Neurônios/fisiologia , Neurônios/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , AMP Cíclico/metabolismoRESUMO
Female sexual receptivity is essential for reproduction of a species. Neuropeptides play the main role in regulating female receptivity. However, whether neuropeptides regulate female sexual receptivity during the neurodevelopment is unknown. Here, we found the peptide hormone prothoracicotropic hormone (PTTH), which belongs to the insect PG (prothoracic gland) axis, negatively regulated virgin female receptivity through ecdysone during neurodevelopment in Drosophila melanogaster. We identified PTTH neurons as doublesex-positive neurons, they regulated virgin female receptivity before the metamorphosis during the third-instar larval stage. PTTH deletion resulted in the increased EcR-A expression in the whole newly formed prepupae. Furthermore, the ecdysone receptor EcR-A in pC1 neurons positively regulated virgin female receptivity during metamorphosis. The decreased EcR-A in pC1 neurons induced abnormal morphological development of pC1 neurons without changing neural activity. Among all subtypes of pC1 neurons, the function of EcR-A in pC1b neurons was necessary for virgin female copulation rate. These suggested that the changes of synaptic connections between pC1b and other neurons decreased female copulation rate. Moreover, female receptivity significantly decreased when the expression of PTTH receptor Torso was reduced in pC1 neurons. This suggested that PTTH not only regulates female receptivity through ecdysone but also through affecting female receptivity associated neurons directly. The PG axis has similar functional strategy as the hypothalamic-pituitary-gonadal axis in mammals to trigger the juvenile-adult transition. Our work suggests a general mechanism underlying which the neurodevelopment during maturation regulates female sexual receptivity.
Assuntos
Proteínas de Drosophila , Drosophila melanogaster , Hormônios de Inseto , Neurônios , Receptores de Esteroides , Comportamento Sexual Animal , Animais , Drosophila melanogaster/fisiologia , Drosophila melanogaster/crescimento & desenvolvimento , Feminino , Comportamento Sexual Animal/fisiologia , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Neurônios/fisiologia , Neurônios/metabolismo , Hormônios de Inseto/metabolismo , Receptores de Esteroides/metabolismo , Receptores de Esteroides/genética , Ecdisona/metabolismo , Metamorfose Biológica/fisiologia , Masculino , Larva/crescimento & desenvolvimento , Larva/fisiologia , Proteínas de InsetosRESUMO
Cell division is fundamental to all healthy tissue growth, as well as being rate-limiting in the tissue repair response to wounding and during cancer progression. However, the role that cell divisions play in tissue growth is a collective one, requiring the integration of many individual cell division events. It is particularly difficult to accurately detect and quantify multiple features of large numbers of cell divisions (including their spatio-temporal synchronicity and orientation) over extended periods of time. It would thus be advantageous to perform such analyses in an automated fashion, which can naturally be enabled using deep learning. Hence, we develop a pipeline of deep learning models that accurately identify dividing cells in time-lapse movies of epithelial tissues in vivo. Our pipeline also determines their axis of division orientation, as well as their shape changes before and after division. This strategy enables us to analyse the dynamic profile of cell divisions within the Drosophila pupal wing epithelium, both as it undergoes developmental morphogenesis and as it repairs following laser wounding. We show that the division axis is biased according to lines of tissue tension and that wounding triggers a synchronised (but not oriented) burst of cell divisions back from the leading edge.
Assuntos
Divisão Celular , Aprendizado Profundo , Drosophila melanogaster , Morfogênese , Asas de Animais , Animais , Epitélio/fisiologia , Epitélio/crescimento & desenvolvimento , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/citologia , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/fisiologia , Drosophila melanogaster/citologia , Células Epiteliais/fisiologia , Células Epiteliais/citologia , Drosophila/fisiologia , Cicatrização/fisiologia , Imagem com Lapso de Tempo/métodosRESUMO
Connectomics approaches are fundamentally changing the way scientists investigate the brain. Recently published connectomes have enabled dissection of the intricate motor circuits in the fly's version of the spinal cord on a synaptic level. This has allowed reconstruction of complete sensorimotor pathways in Drosophila.
Assuntos
Conectoma , Animais , Drosophila/fisiologia , Neurociências , Drosophila melanogaster/fisiologia , Medula Espinal/fisiologiaRESUMO
Organisms have evolved the ability to detect, process, and respond to many different surrounding stimuli in order to successfully navigate their environments. Sensory experiences can also be stored and referenced in the form of memory. The Drosophila larva is a simple model organism that can store associative memories during classical conditioning, and is well-suited for studying learning and memory at a fundamental level. Much progress has been made in understanding larval learning behavior and the associated neural circuitry for olfactory conditioning, but other sensory systems are relatively unexplored. Here, we investigate memory formation in larvae treated with a temperature-based associative conditioning protocol, pairing normally neutral temperatures with appetitive (fructose, FRU) or aversive (salt, NaCl) stimuli. We test associative memory using thermal gradient geometries, and quantify navigation strength towards or away from conditioned temperatures. We find that larvae demonstrate short-term associative learning. They navigate towards warmer or cooler temperatures paired with FRU, and away from warmer or cooler temperatures paired with NaCl. These results, especially when combined with future investigations of thermal memory circuitry in larvae, should provide broader insight into how sensory stimuli are encoded and retrieved in insects and more complex systems.
Assuntos
Larva , Memória , Temperatura , Animais , Larva/fisiologia , Memória/fisiologia , Condicionamento Clássico/fisiologia , Comportamento Apetitivo/fisiologia , Drosophila/fisiologia , Aprendizagem por Associação/fisiologia , Drosophila melanogaster/fisiologia , Aprendizagem da Esquiva/fisiologiaRESUMO
Ovulation is critical for sexual reproduction and consists of the process of liberating fertilizable oocytes from their somatic follicle capsules, also known as follicle rupture. The mechanical force for oocyte expulsion is largely unknown in many species. Our previous work demonstrated that Drosophila ovulation, as in mammals, requires the proteolytic degradation of the posterior follicle wall and follicle rupture to release the mature oocyte from a layer of somatic follicle cells. Here, we identified actomyosin contraction in somatic follicle cells as the major mechanical force for follicle rupture. Filamentous actin (F-actin) and nonmuscle myosin II (NMII) are highly enriched in the cortex of follicle cells upon stimulation with octopamine (OA), a monoamine critical for Drosophila ovulation. Pharmacological disruption of F-actin polymerization prevented follicle rupture without interfering with the follicle wall breakdown. In addition, we demonstrated that OA induces Rho1 guanosine triphosphate (GTP)ase activation in the follicle cell cortex, which activates Ras homolog (Rho) kinase to promote actomyosin contraction and follicle rupture. All these results led us to conclude that OA signaling induces actomyosin cortex enrichment and contractility, which generates the mechanical force for follicle rupture during Drosophila ovulation. Due to the conserved nature of actomyosin contraction, this work could shed light on the mechanical force required for follicle rupture in other species including humans.
Assuntos
Actomiosina , Proteínas de Drosophila , Octopamina , Folículo Ovariano , Ovulação , Animais , Actomiosina/metabolismo , Ovulação/fisiologia , Folículo Ovariano/metabolismo , Folículo Ovariano/fisiologia , Feminino , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Octopamina/metabolismo , Actinas/metabolismo , Drosophila melanogaster/fisiologia , Miosina Tipo II/metabolismo , Epitélio/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Oócitos/metabolismo , Drosophila/fisiologiaRESUMO
Animals' ability to orient and navigate relies on selecting an appropriate motor response based on the perception and integration of the environmental information. This is the case, for instance, of the optokinetic response (OKR) in Drosophila melanogaster, where optic flow visual stimulation modulates head movements. Despite a large body of literature on the OKR, there is still a limited understanding, in flies, of the impact on OKR of concomitant, and potentially conflicting, inputs. To evaluate the impact of this multimodal integration, we combined in D. melanogaster, while flying in a tethered condition, the optic flow stimulation leading to OKR with the simultaneous presentation of olfactory cues, based on repellent or masking compounds typically used against noxious insect species. First, this approach allowed us to directly quantify the effect of several substances and of their concentration on the dynamics of the flies' OKR in response to moving gratings by evaluating the number of saccades and the velocity of the slow phase. Subsequently, this analysis was capable of easily revealing the actual effect, i.e. masking vs. repellent, of the compound tested. In conclusion, we show that D. melanogaster, a cost-affordable species, represents a viable option for studying the effects of several compounds on the navigational abilities of insects.
Assuntos
Drosophila melanogaster , Repelentes de Insetos , Odorantes , Animais , Drosophila melanogaster/fisiologia , Drosophila melanogaster/efeitos dos fármacos , Odorantes/análise , Repelentes de Insetos/farmacologia , Estimulação Luminosa , Fluxo Óptico/fisiologiaRESUMO
In modern human societies, social isolation acts as a negative factor for health and life quality. On the other hand, social interaction also has profound effects on animal and human, impacting aggressiveness, feeding and sleep, among many other behaviors. Here, we observe that in the fly Drosophila melanogaster these behavioral changes long-last even after social interaction has ceased, suggesting that the socialization experience triggers behavioral plasticity. These modified behaviors maintain similar levels for 24 h and persist up to 72 h, although showing a progressive decay. We also find that impairing long-term memory mechanisms either genetically or by anesthesia abolishes the expected behavioral changes in response to social interaction. Furthermore, we show that socialization increases CREB-dependent neuronal activity and synaptic plasticity in the mushroom body, the main insect memory center analogous to mammalian hippocampus. We propose that social interaction triggers socialization awareness, understood as long-lasting changes in behavior caused by experience with mechanistic similarities to long-term memory formation.
Assuntos
Comportamento Animal , Drosophila melanogaster , Corpos Pedunculados , Socialização , Animais , Drosophila melanogaster/fisiologia , Comportamento Animal/fisiologia , Corpos Pedunculados/fisiologia , Plasticidade Neuronal , Memória de Longo Prazo/fisiologia , Interação SocialRESUMO
A-to-I RNA editing is a cellular mechanism that generates transcriptomic and proteomic diversity, which is essential for neuronal and immune functions. It involves the conversion of specific adenosines in RNA molecules to inosines, which are recognized as guanosines by cellular machinery. Despite the vast number of editing sites observed across the animal kingdom, pinpointing critical sites and understanding their in vivo functions remains challenging. Here, we study the function of an evolutionary conserved editing site in Drosophila, located in glutamate-gated chloride channel (GluClα). Our findings reveal that flies lacking editing at this site exhibit reduced olfactory responses to odors and impaired pheromone-dependent social interactions. Moreover, we demonstrate that editing of this site is crucial for the proper processing of olfactory information in projection neurons. Our results highlight the value of using evolutionary conservation as a criterion for identifying editing events with potential functional significance and paves the way for elucidating the intricate link between RNA modification, neuronal physiology, and behavior.