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1.
Adv Exp Med Biol ; 1131: 881-900, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31646538

RESUMO

Drosophila melanogaster, colloquially known as the fruit fly, is one of the most commonly used model organisms in scientific research. Although the final architecture of a fly and a human differs greatly, most of the fundamental biological mechanisms and pathways controlling development and survival are conserved through evolution between the two species. For this reason, Drosophila has been productively used as a model organism for over a century, to study a diverse range of biological processes, including development, learning, behavior and aging. Ca2+ signaling comprises complex pathways that impact on virtually every aspect of cellular physiology. Within such a complex field of study, Drosophila offers the advantages of consolidated molecular and genetic techniques, lack of genetic redundancy and a completely annotated genome since 2000. These and other characteristics provided the basis for the identification of many genes encoding Ca2+ signaling molecules and the disclosure of conserved Ca2+ signaling pathways. In this review, we will analyze the applications of Ca2+ imaging in the fruit fly model, highlighting in particular their impact on the study of normal brain function and pathogenesis of neurodegenerative diseases.


Assuntos
Cálcio , Drosophila melanogaster , Animais , Encéfalo/fisiologia , Encéfalo/fisiopatologia , Cálcio/metabolismo , Drosophila melanogaster/fisiologia , Humanos , Modelos Animais
2.
Nat Commun ; 10(1): 3097, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31308381

RESUMO

Dopaminergic neurons in the brain of the Drosophila larva play a key role in mediating reward information to the mushroom bodies during appetitive olfactory learning and memory. Using optogenetic activation of Kenyon cells we provide evidence that recurrent signaling exists between Kenyon cells and dopaminergic neurons of the primary protocerebral anterior (pPAM) cluster. Optogenetic activation of Kenyon cells paired with odor stimulation is sufficient to induce appetitive memory. Simultaneous impairment of the dopaminergic pPAM neurons abolishes appetitive memory expression. Thus, we argue that dopaminergic pPAM neurons mediate reward information to the Kenyon cells, and in turn receive feedback from Kenyon cells. We further show that this feedback signaling is dependent on short neuropeptide F, but not on acetylcholine known to be important for odor-shock memories in adult flies. Our data suggest that recurrent signaling routes within the larval mushroom body circuitry may represent a mechanism subserving memory stabilization.


Assuntos
Encéfalo/fisiologia , Neurônios Dopaminérgicos/fisiologia , Drosophila melanogaster/fisiologia , Memória/fisiologia , Corpos Pedunculados/fisiologia , Recompensa , Acetilcolina/metabolismo , Animais , Apetite/fisiologia , Encéfalo/citologia , Condicionamento Clássico , Retroalimentação Fisiológica , Larva , Modelos Psicológicos , Corpos Pedunculados/citologia , Vias Neurais/fisiologia , Neuropeptídeos/metabolismo , Odorantes , Percepção Olfatória/fisiologia , Optogenética
3.
Nat Commun ; 10(1): 2654, 2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-31201326

RESUMO

Animal locomotion requires spatiotemporally coordinated contraction of muscles throughout the body. Here, we investigate how contractions of antagonistic groups of muscles are intersegmentally coordinated during bidirectional crawling of Drosophila larvae. We identify two pairs of higher-order premotor excitatory interneurons present in each abdominal neuromere that intersegmentally provide feedback to the adjacent neuromere during motor propagation. The two feedback neuron pairs are differentially active during either forward or backward locomotion but commonly target a group of premotor interneurons that together provide excitatory inputs to transverse muscles and inhibitory inputs to the antagonistic longitudinal muscles. Inhibition of either feedback neuron pair compromises contraction of transverse muscles in a direction-specific manner. Our results suggest that the intersegmental feedback neurons coordinate contraction of synergistic muscles by acting as delay circuits representing the phase lag between segments. The identified circuit architecture also shows how bidirectional motor networks could be economically embedded in the nervous system.


Assuntos
Retroalimentação Fisiológica , Locomoção/fisiologia , Rede Nervosa/fisiologia , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/genética , Drosophila melanogaster/fisiologia , Interneurônios/fisiologia , Larva/fisiologia , Microscopia Eletrônica , Modelos Animais , Contração Muscular/fisiologia , Músculos/inervação , Músculos/fisiologia , Optogenética
4.
BMC Bioinformatics ; 20(Suppl 8): 290, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182028

RESUMO

BACKGROUND: It is of great clinical significance to develop an accurate computer aided system to accurately diagnose the breast cancer. In this study, an enhanced machine learning framework is established to diagnose the breast cancer. The core of this framework is to adopt fruit fly optimization algorithm (FOA) enhanced by Levy flight (LF) strategy (LFOA) to optimize two key parameters of support vector machine (SVM) and build LFOA-based SVM (LFOA-SVM) for diagnosing the breast cancer. The high-level features abstracted from the volunteers are utilized to diagnose the breast cancer for the first time. RESULTS: In order to verify the effectiveness of the proposed method, 10-fold cross-validation method is used to make comparison among the proposed method, FOA-SVM (model based on original FOA), PSO-SVM (model based on original particle swarm optimization), GA-SVM (model based on genetic algorithm), random forest, back propagation neural network and SVM. The main novelty of LFOA-SVM lies in the combination of FOA with LF strategy that enhances the quality for FOA, thus improving the convergence rate of the FOA optimization process as well as the probability of escaping from local optimal solution. CONCLUSIONS: The experimental results demonstrate that the proposed LFOA-SVM method can beat other counterparts in terms of various performance metrics. It can very well distinguish malignant breast cancer from benign ones and assist the doctor with clinical diagnosis.


Assuntos
Neoplasias da Mama/diagnóstico , Drosophila melanogaster/fisiologia , Máquina de Vetores de Suporte , Animais , Feminino , Humanos , Redes Neurais (Computação) , Reprodutibilidade dos Testes
5.
Bull Environ Contam Toxicol ; 103(2): 233-239, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31230133

RESUMO

We aimed to identify genetic variation in the response of reproductive behaviors to lead (Pb2+) exposure. We reared a subset of the Drosophila Genetic Reference Panel (DGRP) inbred lines on control or Pb-treated (500 µM PbAc) medium and tested for differences in copulation latency, copulation duration, and fecundity. Pb exposure decreased fecundity (p < 0.05) and increased copulation duration (p < 0.05) across DGRP lines. We found intraspecific genetic variation in latency, duration, and fecundity in both control and Pb-treated flies, with heritability ranging from 0.45 to 0.80. We found a significant genotype-by-environment interaction for copulation duration (p < 0.05). Genetic correlation matrices revealed significant genetic variation in common between control and Pb-treated flies for each trait (p < 0.05). Our results indicate that intraspecific genetic variation plays a role in Pb susceptibility and emphasize the importance of considering the impacts of variation in susceptibility to Pb pollution.


Assuntos
Copulação/efeitos dos fármacos , Drosophila melanogaster/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Variação Genética , Chumbo/toxicidade , Animais , Drosophila melanogaster/genética , Drosophila melanogaster/fisiologia , Fertilidade/efeitos dos fármacos , Fertilidade/genética , Fenótipo
6.
Nat Neurosci ; 22(7): 1132-1139, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31182867

RESUMO

An approaching predator and self-motion toward an object can generate similar looming patterns on the retina, but these situations demand different rapid responses. How central circuits flexibly process visual cues to activate appropriate, fast motor pathways remains unclear. Here we identify two descending neuron (DN) types that control landing and contribute to visuomotor flexibility in Drosophila. For each, silencing impairs visually evoked landing, activation drives landing, and spike rate determines leg extension amplitude. Critically, visual responses of both DNs are severely attenuated during non-flight periods, effectively decoupling visual stimuli from the landing motor pathway when landing is inappropriate. The flight-dependence mechanism differs between DN types. Octopamine exposure mimics flight effects in one, whereas the other probably receives neuronal feedback from flight motor circuits. Thus, this sensorimotor flexibility arises from distinct mechanisms for gating action-specific descending pathways, such that sensory and motor networks are coupled or decoupled according to the behavioral state.


Assuntos
Drosophila melanogaster/fisiologia , Reação de Fuga/fisiologia , Voo Animal/fisiologia , Atividade Motora/fisiologia , Vias Neurais/fisiologia , Neurônios/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Potenciais de Ação , Animais , Vias Eferentes/fisiologia , Octopamina/farmacologia , Técnicas de Patch-Clamp , Estimulação Luminosa
7.
Brain Nerve ; 71(6): 599-609, 2019 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-31171757

RESUMO

Many animals use acoustic information to recognize conspecifics. The time interval between acoustic elements is a property that characterizes a particular sound. In vertebrates and invertebrates, a specific time interval between acoustic elements is represented as a selective pattern of neuronal activity. Excitatory and inhibitory inputs to the auditory neural circuit generate this selectivity. However, the direct causal link between these inhibitory systems and the behavioral response of an animal to a sound with a specific time interval remains unknown. To tackle this question, in this study, we used Drosophila melanogaster, which has a courtship song with a species-specific time interval. Song information in these flies is transmitted along the main songrelay neural pathway, through which the time interval selectivity of the neurons is sequentially transformed. Herein, we examined the mechanism that shapes the selectivity of the key secondary auditory neurons in this pathway, AMMC-B1. Calcium imaging experiments suggested that AMMC-B1 neurons receive GABAergic inhibitory inputs. Anatomical analysis suggested that two GABAergic neurons configure the feed-forward pathways onto the excitatory pathway between AMMC-B1 neurons and their upstream neurons. Calcium imaging and behavioral analysis suggested that each GABAergic neuron shaped the response selectivity of AMMC-B1 neurons, and suppressed the songresponse behavior of the flies. Based on these results, it therefore appears that GABAergic inhibitory feed-forward pathways shape the tuning pattern of AMMC-B1 neurons and adjust the fly's behavioral response to the song.


Assuntos
Corte , Drosophila melanogaster/fisiologia , Neurônios GABAérgicos/fisiologia , Vias Neurais , Vocalização Animal , Animais , Som
8.
Nat Commun ; 10(1): 2219, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31101825

RESUMO

A long-standing question in the field of embryogenesis is how the zygotic genome is precisely activated by maternal factors, allowing normal early embryonic development. We have previously shown that N6-methyladenine (6mA) DNA modification is highly dynamic in early Drosophila embryos and forms an epigenetic mark. However, little is known about how 6mA-formed epigenetic information is decoded. Here we report that the Fox-family protein Jumu binds 6mA-marked DNA and acts as a maternal factor to regulate the maternal-to-zygotic transition. We find that zelda encoding the pioneer factor Zelda is marked by 6mA. Our genetic assays suggest that Jumu controls the proper zygotic genome activation (ZGA) in early embryos, at least in part, by regulating zelda expression. Thus, our findings not only support that the 6mA-formed epigenetic marks can be read by specific transcription factors, but also uncover a mechanism by which the Jumu regulates ZGA partially through Zelda in early embryos.


Assuntos
DNA/metabolismo , Proteínas de Drosophila/metabolismo , Desenvolvimento Embrionário/fisiologia , Fatores de Transcrição/metabolismo , Zigoto/metabolismo , Adenina/análogos & derivados , Adenina/metabolismo , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/genética , Drosophila melanogaster/fisiologia , Embrião não Mamífero , Epigênese Genética/fisiologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Técnicas de Silenciamento de Genes , Genoma de Inseto , Masculino , Fatores de Transcrição/genética
9.
Behav Processes ; 164: 133-142, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31051219

RESUMO

Starting in late 1980's, Bill Timberlake and associates conducted a series of experiments on anticipatory contrast which showed that rats' feeding decisions were regulated by the nutritive value of currently ingested and anticipated food. The effects of nutrient sensing on feeding regulation have been studied intensively in rodents, and recently, in the fruit fly Drosophila melanogaster. In this study, we developed a new behavioral test to study rapid feeding decisions of tethered flies within 6-8 s of ingestion. Using a two-phase experimental design, we presented individual flies one of four serial combinations of a non-nutritive sugar, arabinose, or a nutritive sugar, sucrose. Feeding decisions of wildtype (Canton-S) flies are altered both by immediate effects of nutrient sensing and 1-hour delayed effects of nutrient-feeding, and the two effects act additively to yield a signature pattern of behavioral contrast based on nutritive contrast. Feeding phenotype of flies that carry a mutation of the dSLC5A11 (cupcake) gene varied with the mutant allele and genetic background. Fasted dSLC5A11 mutants showed an overeating phenotype and a defect in short-term feeding regulation irrespective of the nutritive value of sugar. Flies that carried the dSLC5A111 allele showed differential feeding for arabinose and sucrose. However, dSLC5A112 allele yielded a conspicuous deficit in delayed effects of nutrient ingestion, but only when it was expressed on a Canton-S background. Our results suggest that dSLC5A11 might function to integrate external stimulus properties and internal state for feeding regulation and action selection.


Assuntos
Tomada de Decisões , Proteínas de Drosophila/genética , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/fisiologia , Comportamento Alimentar/fisiologia , Nutrientes/fisiologia , Proteínas de Transporte de Sódio-Glucose/genética , Proteínas de Transporte de Sódio-Glucose/fisiologia , Alelos , Animais , Arabinose , Drosophila melanogaster/genética , Mutação , Valor Nutritivo , Percepção/fisiologia , Fenótipo , Ratos , Sacarose , Fatores de Tempo
10.
Genes Cells ; 24(7): 496-510, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31124270

RESUMO

In the Drosophila brain, neurons form genetically specified synaptic connections with defined neuronal targets. It is proposed that each central nervous system neuron expresses specific cell surface proteins, which act as identification tags. Through an RNAi screen of cell surface molecules in the Drosophila visual system, we found that the cell adhesion molecule Klingon (Klg) plays an important role in repressing the ectopic formation of extended axons, preventing the formation of excessive synapses. Cell-specific manipulation of klg showed that Klg is required in both photoreceptors and the glia, suggesting that the balanced homophilic interaction between photoreceptor axons and the glia is required for normal synapse formation. Previous studies suggested that Klg binds to cDIP and our genetic analyses indicate that cDIP is required in glia for ectopic synaptic repression. These data suggest that Klg play a critical role together with cDIP in refining synaptic specificity and preventing unnecessary connections in the brain.


Assuntos
Moléculas de Adesão Celular/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiologia , Proteínas do Olho/metabolismo , Neuroglia/fisiologia , Células Fotorreceptoras de Invertebrados/fisiologia , Sinapses/fisiologia , Vias Visuais , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/fisiologia , Axônios/fisiologia , Moléculas de Adesão Celular/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Proteínas do Olho/genética , Feminino
11.
Nat Protoc ; 14(5): 1455-1488, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30953041

RESUMO

Sleep is nearly universal among animals, yet remains poorly understood. Recent work has leveraged simple model organisms, such as Caenorhabditis elegans and Drosophila melanogaster larvae, to investigate the genetic and neural bases of sleep. However, manual methods of recording sleep behavior in these systems are labor intensive and low in throughput. To address these limitations, we developed methods for quantitative imaging of individual animals cultivated in custom microfabricated multiwell substrates, and used them to elucidate molecular mechanisms underlying sleep. Here, we describe the steps necessary to design, produce, and image these plates, as well as analyze the resulting behavioral data. We also describe approaches for experimentally manipulating sleep. Following these procedures, after ~2 h of experimental preparation, we are able to simultaneously image 24 C. elegans from the second larval stage to adult stages or 20 Drosophila larvae during the second instar life stage at a spatial resolution of 10 or 27 µm, respectively. Although this system has been optimized to measure activity and quiescence in Caenorhabditis larvae and adults and in Drosophila larvae, it can also be used to assess other behaviors over short or long periods. Moreover, with minor modifications, it can be adapted for the behavioral monitoring of a wide range of small animals.


Assuntos
Caenorhabditis elegans/fisiologia , Drosophila melanogaster/fisiologia , Processamento de Imagem Assistida por Computador/métodos , Larva/fisiologia , Sono/fisiologia , Animais , Comportamento Animal/fisiologia , Microscopia , Fotografação
12.
BMC Genomics ; 20(1): 305, 2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31014230

RESUMO

BACKGROUND: Evolutionary theory indicates that the dynamics of aging in the soma and reproductive tissues may be distinct. This difference arises from the fact that only the germline lineage establishes future generations. In the soma, changes in the landscape of heterochromatin have been proposed to have an important role in aging. This is because redistribution of heterochromatin during aging has been linked to the derepression of transposable elements and an overall loss of somatic gene regulation. A role for changes in the chromatin landscape in the aging of reproductive tissues is less well established. Whether or not epigenetic factors, such as heterochromatin marks, are perturbed in aging reproductive tissues is of interest because, in special cases, epigenetic variation may be heritable. Using mRNA sequencing data from late-stage egg chambers in Drosophila melanogaster, we characterized the landscape of altered gene and transposable element expression in aged reproductive tissues. This allowed us to test the hypothesis that reproductive tissues may differ from somatic tissues in their response to aging. RESULTS: We show that age-related expression changes in late-stage egg chambers tend to occur in genes residing in heterochromatin, particularly on the largely heterochromatic 4th chromosome. However, these expression differences are seen as both decreases and increases during aging, inconsistent with a general loss of heterochromatic silencing. We also identify an increase in expression of the piRNA machinery, suggesting an age-related increased investment in the maintenance of genome stability. We further identify a strong age-related reduction in the expression of mitochondrial transcripts. However, we find no evidence for global TE derepression in reproductive tissues. Rather, the observed effects of aging on TEs are primarily strain and family specific. CONCLUSIONS: These results identify unique responses in somatic versus reproductive tissue with regards to aging. As in somatic tissues, female reproductive tissues show reduced expression of mitochondrial genes. In contrast, the piRNA machinery shows increased expression during aging. Overall, these results also indicate that global loss of TE control observed in other studies may be unique to the soma and sensitive to genetic background and TE family.


Assuntos
Envelhecimento/genética , Elementos de DNA Transponíveis/genética , Drosophila melanogaster/fisiologia , Perfilação da Expressão Gênica , Mitocôndrias/genética , Ovário/fisiologia , RNA Interferente Pequeno/genética , Animais , Drosophila melanogaster/genética , Feminino , Genoma Mitocondrial/genética , Heterocromatina/genética , Óvulo/metabolismo , RNA Mensageiro/genética
13.
J Therm Biol ; 81: 25-32, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30975420

RESUMO

In seasonal environments, natural selection should favor genotypes that acclimate to slow and predictable changes in temperature. Selective pressure for acclimation should be especially strong for animals that complete many generations per year, because seasonal warming or cooling causes offspring to experience different temperatures than their parents did. Here, we studied variation in acclimation capacity among three populations of Drosophila melanogaster. We used a reverse acclimation design to see whether developmental acclimation persisted throughout adulthood. Flies developed from fertilization to adulthood at either 16° or 26 °C. Then, flies either remained at the same temperature or moved to the other temperature for 7 days. We measured fecundity at seven temperatures ranging from 14° to 36°C. Genotypes from North Carolina and Vermont laid more eggs at 16 °C after spending the larval and adult stages at 16 °C, instead of 26 °C. In both populations, the benefit of acclimation to 16 °C during development was erased by acclimation to 26 °C during adulthood. In contrast to our prediction, genotypes from Indiana laid fewer eggs at 16 °C or 26 °C after developing at this temperature. Overall, these data provide only weak support for the models of optimal acclimation in seasonal environments.


Assuntos
Drosophila melanogaster/fisiologia , Estações do Ano , Termotolerância , Animais , Temperatura Corporal , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Feminino , Fertilidade , Genótipo , Masculino , Modelos Biológicos , Temperatura Ambiente , Asas de Animais/crescimento & desenvolvimento
14.
Nat Commun ; 10(1): 1085, 2019 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-30842428

RESUMO

Neuronal communication across synapses relies on neurotransmitter release from presynaptic active zones (AZs) followed by postsynaptic transmitter detection. Synaptic plasticity homeostatically maintains functionality during perturbations and enables memory formation. Postsynaptic plasticity targets neurotransmitter receptors, but presynaptic mechanisms regulating the neurotransmitter release apparatus remain largely enigmatic. By studying Drosophila neuromuscular junctions (NMJs) we show that AZs consist of nano-modular release sites and identify a molecular sequence that adds modules within minutes of inducing homeostatic plasticity. This requires cognate transport machinery and specific AZ-scaffolding proteins. Structural remodeling is not required for immediate potentiation of neurotransmitter release, but necessary to sustain potentiation over longer timescales. Finally, mutations in Unc13 disrupting homeostatic plasticity at the NMJ also impair short-term memory when central neurons are targeted, suggesting that both plasticity mechanisms utilize Unc13. Together, while immediate synaptic potentiation capitalizes on available material, it triggers the coincident incorporation of modular release sites to consolidate synaptic potentiation.


Assuntos
Proteínas de Drosophila/metabolismo , Potenciação de Longa Duração/fisiologia , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Junção Neuromuscular/metabolismo , Neurotransmissores/metabolismo , Terminações Pré-Sinápticas/metabolismo , Animais , Animais Geneticamente Modificados , Comportamento Animal , Proteínas de Drosophila/genética , Drosophila melanogaster/fisiologia , Feminino , Masculino , Proteínas de Membrana/genética , Memória de Curto Prazo/fisiologia , Modelos Animais , Corpos Pedunculados/citologia , Corpos Pedunculados/metabolismo , Proteínas do Tecido Nervoso/genética , Técnicas de Patch-Clamp , Transmissão Sináptica/fisiologia , Vesículas Sinápticas/metabolismo
15.
Sci Total Environ ; 667: 455-463, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30833244

RESUMO

Animal food wastes are a concern due to the large amounts of commercial food required for model animals during the biological and biomedical research. Searching for sustainable food alternatives with negligible physiological effects on animals is critical to solve or reduce this challenge. Microalgae have been demonstrated to be suitable for both human consumption and animal feed. In this study, the possibility of using Chlorella vulgaris and Senedesmus obliquus as a feed replacement to Drosophila melanogaster, one of the fly models commonly used in biomedical studies, was investigated. Characteristics including the fly locomotor activity, motor pattern, feeding behavior, lifespan and body weight were assessed. Results showed that compared to control, the flies fed on 80% microalga (80-flies) in the total weight (w/w) had the double increased apparent step size, while both 60-flies and 80-flies exhibited longer travel distances (60%: 27.77 ±â€¯1.99 cm; 80%: 31.50 ±â€¯3.70 cm) most likely due to the starvation and varied serotonin levels in flies fed on high percentages microalgae. Subsequently, 40-flies exhibited less optimal growth performance with decreased body weights (0.51 ±â€¯0.006 mg vs 0.60 ±â€¯0.005 mg for control) and shorter mean lifespan (36 days vs 55.8 days for control. However, 20-flies showed no statistical differences in all parameters tested with respect to control flies, indicating that 20% microalgae treatment did not greatly change the primary food component such as carbohydrate which might play a critical role in fly performance. Therefore, the inclusion of 20% microalgae could be an alternative to fly standard food without compromising fly physiological performance.


Assuntos
Ração Animal , Drosophila melanogaster/fisiologia , Microalgas , Animais , Chlorella vulgaris , Drosophila/fisiologia , Comportamento Alimentar , Modelos Animais
16.
Nat Commun ; 10(1): 1201, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30867415

RESUMO

Evaluating odor blends in sensory processing is a crucial step for signal recognition and execution of behavioral decisions. Using behavioral assays and 2-photon imaging, we have characterized the neural and behavioral correlates of mixture perception in the olfactory system of Drosophila. Mixtures of odors with opposing valences elicit strong inhibition in certain attractant-responsive input channels. This inhibition correlates with reduced behavioral attraction. We demonstrate that defined subsets of GABAergic interneurons provide the neuronal substrate of this computation at pre- and postsynaptic loci via GABAB- and GABAA receptors, respectively. Intriguingly, manipulation of single input channels by silencing and optogenetic activation unveils a glomerulus-specific crosstalk between the attractant- and repellent-responsive circuits. This inhibitory interaction biases the behavioral output. Such a form of selective lateral inhibition represents a crucial neuronal mechanism in the processing of conflicting sensory information.


Assuntos
Drosophila melanogaster/fisiologia , Odorantes , Bulbo Olfatório/fisiologia , Condutos Olfatórios/fisiologia , Percepção Olfatória/fisiologia , Animais , Animais Geneticamente Modificados , Antenas de Artrópodes/inervação , Comportamento Animal/fisiologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Feminino , Neurônios GABAérgicos/fisiologia , Potenciais Pós-Sinápticos Inibidores/fisiologia , Interneurônios/fisiologia , Neurônios Receptores Olfatórios/fisiologia , Optogenética , Receptores Odorantes/genética , Receptores Odorantes/fisiologia
17.
Chemosphere ; 225: 247-258, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30877919

RESUMO

The study reports the effects of an herbicide (atrazine) and a plasticizer (Bisphenol A, BPA) on the transcriptional modulation of a mismatch repair gene (mlh1) and its adverse consequences on female fertility using Drosophila as a model. Through a chemical screen, we show that exposure to atrazine or BPA significantly downregulates mlh1 and the exposed flies had reduced fertility with smaller ovaries having reduced number of mature oocytes and abnormal distribution of ovarian follicles with increased apoptosis in them. These females had increased double-strand breaks as well as reduced synaptonemal complex formation in their ovaries suggesting altered meiotic crossing over. The eggs of these females were defective in their maternal transcripts as well as proteins and consequently, after fertilization, these eggs exhibited abnormal embryonic development. Interestingly, these phenotypes parallel that of mlh1 mutants. Further, exposure of females having reduced Mlh1 levels (mlh1e00130/CyO) to atrazine or BPA caused severe defective phenotypes at a higher proportion than normal flies. Our findings reveal the critical role of mlh1 in atrazine and BPA mediated female reproductive toxicity, and opens up a possibility of toxicants affecting female fertility by modulating the MMR genes.


Assuntos
Atrazina/farmacologia , Compostos Benzidrílicos/farmacologia , Drosophila melanogaster/genética , Drosophila melanogaster/fisiologia , Fertilidade/efeitos dos fármacos , Proteína 1 Homóloga a MutL/genética , Oogênese/genética , Fenóis/farmacologia , Animais , Drosophila melanogaster/efeitos dos fármacos , Feminino , Fertilidade/genética , Herbicidas/farmacologia , Oogênese/efeitos dos fármacos
18.
Environ Sci Pollut Res Int ; 26(15): 15069-15083, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30915696

RESUMO

Methylmercury (MeHg) is a well-known environmental pollutant associated with neurological and developmental deficits in animals and humans. However, epidemiological data showed that people living in the Amazon region although exposed to MeHg do not present these effects probably due to the protective effect of certain foods. We hypothesized here if guarana, a highly caffeinated fruit and consumed on a daily basis by Amazon people, could have some protective effect against MeHg toxicity using two complementary approaches. To assess locomotor impairment and sleep disruption, we used fruit fly (Drosophila melanogaster) model, and to evaluate neuroinflammation, we used human SH-SY5Y neural cells by measuring inflammatory cytokines levels. Results showed that guarana had a protective effect on the locomotor activity of male fruit flies reducing the excessive sleepiness caused by MeHg and increasing daily activity. Also, guarana increased the viability of flies and attenuated neural cells mortality. In addition, guarana reduced all pro-inflammatory cytokines levels increased by MeHg, along with caspase-1, caspase -3, caspase-8, and 8-dOHG levels, whereas increased the anti-inflammatory (IL-10) cytokine levels, which was decreased by MeHg. Our study provides new insights on the protective effects of guarana on the viability, locomotor activity, sleep, and activity patterns in vivo and the in vitro neuronal anti-inflammatory effect against MeHg toxicity.


Assuntos
Drosophila melanogaster/efeitos dos fármacos , Inflamação/induzido quimicamente , Compostos de Metilmercúrio/toxicidade , Neurônios/efeitos dos fármacos , Paullinia , Animais , Caspases/metabolismo , Linhagem Celular , Ritmo Circadiano/efeitos dos fármacos , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Drosophila melanogaster/fisiologia , Humanos , Inflamação/prevenção & controle , Interleucina-10/metabolismo
19.
Science ; 363(6430): 948-955, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30819957

RESUMO

We investigated the roles of components of neuronal synapses for development of the Drosophila air sac primordium (ASP). The ASP, an epithelial tube, extends specialized signaling filopodia called cytonemes that take up signals such as Dpp (Decapentaplegic, a homolog of the vertebrate bone morphogenetic protein) from the wing imaginal disc. Dpp signaling in the ASP was compromised if disc cells lacked Synaptobrevin and Synaptotagmin-1 (which function in vesicle transport at neuronal synapses), the glutamate transporter, and a voltage-gated calcium channel, or if ASP cells lacked Synaptotagmin-4 or the glutamate receptor GluRII. Transient elevations of intracellular calcium in ASP cytonemes correlate with signaling activity. Calcium transients in ASP cells depend on GluRII, are activated by l-glutamate and by stimulation of an optogenetic ion channel expressed in the wing disc, and are inhibited by EGTA and by the GluR inhibitor NASPM (1-naphthylacetyl spermine trihydrochloride). Activation of GluRII is essential but not sufficient for signaling. Cytoneme-mediated signaling is glutamatergic.


Assuntos
Sinalização do Cálcio , Proteínas de Drosophila/fisiologia , Glutamatos/fisiologia , Discos Imaginais/fisiologia , Receptores Ionotrópicos de Glutamato/fisiologia , Sinapses/fisiologia , Animais , Animais Geneticamente Modificados , Canais de Cálcio/fisiologia , Drosophila melanogaster/fisiologia , Imagem Óptica , Pseudópodes/fisiologia , Proteínas R-SNARE/fisiologia , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/fisiologia , Sinaptotagmina I/fisiologia , Técnicas de Cultura de Tecidos
20.
Front Biosci (Landmark Ed) ; 24: 1071-1084, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30844731

RESUMO

Epigenetic regulation in animals induces rapid and long-lasting effects on gene expression in response to environmental changes that frequently affect animal behavior. In the last decade, accumulating studies have revealed how epigenetic regulation affects the behavior of animals, such as learning and memory, mating and courtship, the circadian sleep-wake cycle, and foraging/starvation-induced hyperactivity. In each section of this review, we discuss what we have learned from studies with mammals, mostly mouse models. We then highlight studies with Drosophila models to compare data with mouse models. Finally, we discuss several unanswered questions and future developments in this field.


Assuntos
Comportamento Animal , Drosophila melanogaster/fisiologia , Epigênese Genética , Animais , Ritmo Circadiano , Metilação de DNA , Modelos Animais de Doenças , Proteínas de Drosophila/genética , Feminino , Humanos , Hipercinese , Aprendizagem , Masculino , Memória , Camundongos , Comportamento Sexual Animal
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