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1.
Nat Commun ; 10(1): 4550, 2019 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-31591396

RESUMO

It is believed that long-term memory (LTM) cannot be formed immediately because it must go through a protein synthesis-dependent consolidation process. However, the current study uses Drosophila aversive olfactory conditioning to show that such processes are dispensable for context-dependent LTM (cLTM). Single-trial conditioning yields cLTM that is formed immediately in a protein-synthesis independent manner and is sustained over 14 days without decay. Unlike retrieval of traditional LTM, which requires only the conditioned odour and is mediated by mushroom-body neurons, cLTM recall requires both the conditioned odour and reinstatement of the training-environmental context. It is mediated through lateral-horn neurons that connect to multiple sensory brain regions. The cLTM cannot be retrieved if synaptic transmission from any one of these centres is blocked, with effects similar to those of altered encoding context during retrieval. The present study provides strong evidence that long-term memory can be formed easily without the need for consolidation.


Assuntos
Neurônios Dopaminérgicos/fisiologia , Proteínas de Drosophila/biossíntese , Memória de Longo Prazo/fisiologia , Corpos Pedunculados/fisiologia , Animais , Animais Geneticamente Modificados , Neurônios Dopaminérgicos/metabolismo , Proteínas de Drosophila/genética , Feminino , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Microscopia Confocal , Corpos Pedunculados/citologia , Corpos Pedunculados/metabolismo , Vias Neurais/fisiologia , Odorantes , Transmissão Sináptica/fisiologia
2.
Elife ; 82019 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-31502540

RESUMO

How circuits assemble starting from stem cells is a fundamental question in developmental neurobiology. We test the hypothesis that, in neuronal stem cells, temporal transcription factors predictably control neuronal terminal features and circuit assembly. Using the Drosophila motor system, we manipulate expression of the classic temporal transcription factor Hunchback (Hb) specifically in the NB7-1 stem cell, which produces U motor neurons (MNs), and then we monitor dendrite morphology and neuromuscular synaptic partnerships. We find that prolonged expression of Hb leads to transient specification of U MN identity, and that embryonic molecular markers do not accurately predict U MN terminal features. Nonetheless, our data show Hb acts as a potent regulator of neuromuscular wiring decisions. These data introduce important refinements to current models, show that molecular information acts early in neurogenesis as a switch to control motor circuit wiring, and provide novel insight into the relationship between stem cell and circuit.


Assuntos
Proteínas de Ligação a DNA/biossíntese , Proteínas de Drosophila/biossíntese , Expressão Gênica , Neurônios Motores/fisiologia , Vias Neurais/embriologia , Junção Neuromuscular/fisiologia , Células-Tronco/fisiologia , Fatores de Transcrição/biossíntese , Animais , Drosophila , Neurônios Motores/citologia , Junção Neuromuscular/citologia , Células-Tronco/citologia
3.
Elife ; 82019 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-31439126

RESUMO

During organogenesis, inductive signals cause cell differentiation and morphogenesis. However, how these phenomena are coordinated to form functional organs is poorly understood. Here, we show that cell differentiation of the Drosophila trachea is sequentially determined in two steps and that the second step is synchronous with the invagination of the epithelial sheet. The master gene trachealess is dispensable for the initiation of invagination, while it is essential for maintaining the invaginated structure, suggesting that tracheal morphogenesis and differentiation are separately induced. trachealess expression starts in bipotential tracheal/epidermal placode cells. After invagination, its expression is maintained in the invaginated cells but is extinguished in the remaining sheet cells. A trachealess cis-regulatory module that shows both tracheal enhancer activity and silencer activity in the surface epidermal sheet was identified. We propose that the coupling of trachealess expression with the invaginated structure ensures that only invaginated cells canalize robustly into the tracheal fate.


Assuntos
Proteínas de Drosophila/biossíntese , Regulação da Expressão Gênica no Desenvolvimento , Morfogênese , Traqueia/embriologia , Fatores de Transcrição/biossíntese , Animais , Diferenciação Celular , Drosophila , Células Epiteliais/fisiologia
4.
Mol Cell ; 75(6): 1178-1187.e4, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31402096

RESUMO

In complex genetic loci, individual enhancers interact most often with specific basal promoters. Here we investigate the activation of the Bicoid target gene hunchback (hb), which contains two basal promoters (P1 and P2). Early in embryogenesis, P1 is silent, while P2 is strongly activated. In vivo deletion of P2 does not cause activation of P1, suggesting that P2 contains intrinsic sequence motifs required for activation. We show that a two-motif code (a Zelda binding site plus TATA) is required and sufficient for P2 activation. Zelda sites are present in the promoters of many embryonically expressed genes, but the combination of Zelda plus TATA does not seem to be a general code for early activation or Bicoid-specific activation per se. Because Zelda sites are also found in Bicoid-dependent enhancers, we propose that simultaneous binding to both enhancers and promoters independently synchronizes chromatin accessibility and facilitates correct enhancer-promoter interactions.


Assuntos
Proteínas de Ligação a DNA/biossíntese , Proteínas de Drosophila/biossíntese , Proteínas de Drosophila/metabolismo , Proteínas de Homeodomínio/metabolismo , Motivos de Nucleotídeos , Elementos de Resposta , Transativadores/metabolismo , Fatores de Transcrição/biossíntese , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/genética , Drosophila melanogaster , Proteínas de Homeodomínio/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Transativadores/genética , Fatores de Transcrição/genética
5.
Elife ; 82019 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-31287057

RESUMO

Rapid or even anticipatory adaptation to environmental conditions can provide a decisive fitness advantage to an organism. The memory of recurring conditions could also benefit future generations; however, neuronally-encoded behavior isn't thought to be inherited across generations. We tested the possibility that environmentally triggered modifications could allow 'memory' of parental experiences to be inherited. In Drosophila melanogaster, exposure to predatory wasps leads to inheritance of a predisposition for ethanol-rich food for five generations. Inhibition of Neuropeptide-F (NPF) activates germline caspases required for transgenerational ethanol preference. Further, inheritance of low NPF expression in specific regions of F1 brains is required for the transmission of this food preference: a maternally derived NPF locus is necessary for this phenomenon, implicating a maternal epigenetic mechanism of NPF-repression. Given the conserved signaling functions of NPF and its mammalian NPY homolog in drug and alcohol disorders, these observations raise the intriguing possibility of NPY-related transgenerational effects in humans.


Assuntos
Regulação para Baixo , Proteínas de Drosophila/biossíntese , Drosophila melanogaster/fisiologia , Epigênese Genética , Etanol/metabolismo , Comportamento Alimentar , Neuropeptídeos/biossíntese , Testamentos , Animais
6.
BMC Neurosci ; 20(1): 24, 2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138137

RESUMO

BACKGROUND: Mutants which carry mutations in genes encoding mitochondrial ligases MUL1 and PARKIN are convenient Drosophila models of Parkinson's disease (PD). In several studies it has been shown that in Parkinson's disease sleep disturbance occurs, which may be the result of a disturbed circadian clock. RESULTS: We found that the ROS level was higher, while the anti-oxidant enzyme SOD1 level was lower in mul1A6 and park1 mutants than in the white mutant used as a control. Moreover, mutations of both ligases affected circadian rhythms and the clock. The expression of clock genes per, tim and clock and the level of PER protein were changed in the mutants. Moreover, expression of ATG5, an autophagy protein also involved in circadian rhythm regulation, was decreased in the brain and in PDF-immunoreactive large ventral lateral clock neurons. The observed changes in the molecular clock resulted in a longer period of locomotor activity rhythm, increased total activity and shorter sleep at night. Finally, the lack of both ligases led to decreased longevity and climbing ability of the flies. CONCLUSIONS: All of the changes observed in the brains of these Drosophila models of PD, in which mitochondrial ligases MUL1 and PARKIN do not function, may explain the mechanisms of some neurological and behavioural symptoms of PD.


Assuntos
Encéfalo/metabolismo , Relógios Circadianos/fisiologia , Ritmo Circadiano/fisiologia , Proteínas de Drosophila/fisiologia , Locomoção/fisiologia , Doença de Parkinson/fisiopatologia , Sono/fisiologia , Ubiquitina-Proteína Ligases/fisiologia , Animais , Animais Geneticamente Modificados/fisiologia , Proteínas CLOCK/biossíntese , Modelos Animais de Doenças , Drosophila , Proteínas de Drosophila/biossíntese , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Longevidade/fisiologia , Destreza Motora/fisiologia , Mutação , Neurônios/metabolismo , Doença de Parkinson/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Ubiquitina-Proteína Ligases/genética
7.
Dev Biol ; 450(1): 23-33, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30858024

RESUMO

Development of an organism requires accurate coordination between the growth of a tissue and orientation of cells within the tissue. The large cadherin Fat has been shown to play a role in both of these processes. Fat is involved in the establishment of planar cell polarity and regulates growth through the Hippo pathway, a developmental cascade that controls proliferation and apoptosis. Both Fat and the Hippo pathway are known to regulate transcription of four-jointed, although the nature of this regulation is unknown. In this study, we test whether Fat affects four-jointed transcription via or independently of Hippo pathway. Our analysis of the four-jointed regulatory region reveals a 1.2 kb element that functions as an enhancer for graded expression of Four-jointed in the eye imaginal disc. Within this enhancer element, we identify a 20 bp fragment that is critical for regulation by Fat but not by Hippo. Our findings suggest that Fat and the Hippo pathway control four-jointed expression independently of each other and none of the transcription factors known to function downstream of the Hippo pathway are required to regulate four-jointed expression through the 1.2 kb element.


Assuntos
Moléculas de Adesão Celular , Proteínas de Drosophila , Elementos Facilitadores Genéticos , Regulação da Expressão Gênica no Desenvolvimento , Peptídeos e Proteínas de Sinalização Intracelular , Glicoproteínas de Membrana , Proteínas Serina-Treonina Quinases , Transdução de Sinais , Transcrição Genética , Animais , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Proteínas de Drosophila/biossíntese , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Genes Reporter , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Glicoproteínas de Membrana/biossíntese , Glicoproteínas de Membrana/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo
8.
J Cell Sci ; 132(2)2019 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-30630896

RESUMO

Chromatin assembly factor 1 (CAF1), a histone chaperone that mediates the deposition of histone H3/H4 onto newly synthesized DNA, is involved in Notch signaling activation during Drosophila wing imaginal disc development. Here, we report another side of CAF1, wherein the subunits CAF1-p105 and CAF1-p180 (also known as CAF1-105 and CAF1-180, respectively) inhibit expression of Notch target genes and show this is required for proliferation of Drosophila ovarian follicle cells. Loss-of-function of either CAF1-p105 or CAF1-p180 caused premature activation of Notch signaling reporters and early expression of the Notch target Hindsight (Hnt, also known as Pebbled), leading to Cut downregulation and inhibition of follicle cell mitosis. Our studies further show Notch is functionally responsible for these phenotypes observed in both the CAF1-p105- and CAF1-p180-deficient follicle cells. Moreover, we reveal that CAF1-p105- and CAF1-p180-dependent Cut expression is essential for inhibiting Hnt expression in follicle cells during their mitotic stage. These findings together indicate a novel negative-feedback regulatory loop between Cut and Hnt underlying CAF1-p105 and CAF-p180 regulation, which is crucial for follicle cell differentiation. In conclusion, our studies suggest CAF1 plays a dual role to sustain cell proliferation by positively or negatively regulating Drosophila Notch signaling in a tissue-context-dependent manner.


Assuntos
Proliferação de Células , Proteínas de Drosophila/metabolismo , Folículo Ovariano/metabolismo , Receptores Notch/metabolismo , Proteína 4 de Ligação ao Retinoblastoma/metabolismo , Transdução de Sinais , Animais , Proteínas de Drosophila/biossíntese , Proteínas de Drosophila/genética , Drosophila melanogaster , Feminino , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/genética , Discos Imaginais/citologia , Discos Imaginais/metabolismo , Proteínas Nucleares/biossíntese , Proteínas Nucleares/genética , Folículo Ovariano/citologia , Receptores Notch/genética , Proteína 4 de Ligação ao Retinoblastoma/genética , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética
9.
Dev Biol ; 448(1): 48-58, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30629954

RESUMO

In many biological systems gene expression at mRNA and protein levels is not identical. Rigorous comparison of such differences on a spatio-temporal scale is still not feasible by high-throughput transcriptomic and proteomic analyses of early embryo development. Here, we characterize differences between mRNA and protein expression of Drosophila segmentation genes at the level of individual gene expression domains. We obtained quantitative imaging data on expression of gap genes gt and hb and pair-rule gene eve for Drosophila wild type embryos, Kr null mutants and Kr+/Kr- heterozygotes. To compare mRNA and protein expression we use several criteria including difference in amplitude and positions of expression domains, pattern shape and positional variability. For a number of gene expression domains we show examples where protein expression does not repeat mRNA expression even after a temporal delay. We calculated time delays between eve pattern formation at the level of mRNA and protein for wild type embryos, Kr mutants and Kr+/Kr- heterozygotes. We detect that in wild type embryos, the amplitudes of eve stripes 3 and 7 do not differ significantly at the level of mRNA, however, stripe 3 is higher than stripe 7 at the protein level. We further show that hb mRNA and protein expression in both anterior and posterior domains significantly differs at specific time points. The formation of hb PS4 stripe at the mRNA level proceeds five times faster than at the level of protein. With regard to spatial expression, we show that the offset between posterior gt mRNA and protein domains is much larger in Kr mutants than in wild type embryos and heterozygotes. Finally, we analyze differences in positional variability of eve stripe 7 expression in Kr mutants and Kr+/Kr- heterozygotes at the level of mRNA and protein. These results enable further perspectives to uncover mechanisms underlying discrepancies between mRNA and protein expression in early embryo.


Assuntos
Padronização Corporal/fisiologia , Embrião não Mamífero/embriologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Genótipo , RNA Mensageiro , Animais , Proteínas de Drosophila/biossíntese , Proteínas de Drosophila/genética , Drosophila melanogaster , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/genética , Fatores de Transcrição Kruppel-Like/biossíntese , Fatores de Transcrição Kruppel-Like/genética , Microscopia Confocal , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética
10.
Dev Biol ; 447(2): 147-156, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30695684

RESUMO

Drosophila segmentation is regulated by a complex network of transcription factors that include products of the pair-rule genes (PRGs). PRGs are expressed in early embryos in the primorida of alternate segmental units, establishing the repeated, segmental body plan of the fly. Despite detailed analysis of the regulatory logic among segmentation genes, the relationship between these genes and the morphological formation of segments is still poorly understood, since regulation of transcription factor expression is not sufficient to explain how segments actually form and are maintained. Cell surface proteins containing Leucine rich repeats (LRR) play a variety of roles in development, and those expressed in segmental patterns likely impact segment morphogenesis. Here we explore the relationships between the PRG network and segmentally expressed LRR-encoding (sLRR) genes. We examined expression of Toll2, Toll6, Toll7, Toll8 and tartan (trn) in wild type or PRG mutant embryos. Expression of each sLRR-encoding gene is dynamic, but each has a unique register along the anterior-posterior axis. The registers for different sLRRs are off-set from one another resulting in a continually changing set of overlapping expression patterns among the sLRR-encoding genes themselves and between the sLRR-encoding genes and the PRGs. Accordingly, each sLRR-encoding gene is regulated by a unique combination of PRGs. These findings suggest that one role of the PRG network is to promote segmentation by establishing a cell surface code: each row of cells in the two-segment-wide primordia expresses a unique combination of sLRRs, thereby translating regulatory information from the PRGs to direct segment morphogenesis.


Assuntos
Padronização Corporal , Proteínas de Drosophila/biossíntese , Regulação da Expressão Gênica no Desenvolvimento , Mutação , Fatores de Transcrição/biossíntese , Animais , Proteínas de Drosophila/genética , Drosophila melanogaster , Fatores de Transcrição/genética
11.
Environ Mol Mutagen ; 60(3): 277-285, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30353950

RESUMO

The in vivo model Drosophila melanogaster was used here to determine the detrimental effects induced by silver nanoparticles (AgNPs) exposure. The main aim was to explore its interaction with the intestinal barrier and the genotoxic effects induced in hemocytes. The observed effects were compared with those obtained by silver nitrate, as an agent acting via the release of silver ions. Larvae were fed in food media containing both forms of silver. Results indicated that silver nitrate was more toxic than AgNPs when the viability "egg-to-adult" was determined. Depigmentation was observed in adults including those exposed to nontoxic concentrations, as indicative of exposure action. Interestingly, AgNPs were able to cross the intestinal barrier affecting hemocytes that show significant increases in the levels of intracellular reactive oxygen species. Additionally, significant levels of genotoxic damage, as determined by the comet assay, were also induced. When the expression of different stress-response genes was determined, for both AgNPs and silver nitrate, significant upregulation of Sod2 and p53 genes was observed. Our results confirm for the first time that in an in vivo model as Drosophila, AgNPs are able to cross the intestinal barriers and produce primary DNA damage (comet assay) via oxidative stress induction. In general, the effects induced by silver nitrate were more pronounced than those induced by AgNPs what would emphasize the role of silver ions in the observed effects. Environ. Mol. Mutagen. 60:277-285, 2019. © 2018 Wiley Periodicals, Inc.


Assuntos
Dano ao DNA/efeitos dos fármacos , Drosophila melanogaster/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Nitrato de Prata/toxicidade , Prata/toxicidade , Animais , Proteínas de Drosophila/biossíntese , Proteínas de Drosophila/genética , Hemócitos/efeitos dos fármacos , Testes de Mutagenicidade , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/biossíntese , Superóxido Dismutase/genética , Junções Íntimas/metabolismo , Proteína Supressora de Tumor p53/biossíntese , Proteína Supressora de Tumor p53/genética
12.
Gene ; 686: 141-145, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30399425

RESUMO

Gene duplication could promote phenotypic and genetic adaptation to various environments. To understand the effects of gene duplication on transcriptional regulation associated with environmental changes, we focused on the starch hydrolysis pathway, in which amylase enzymes together with maltase enzymes hydrolyze starch into glucose. Drosophila genomes involve ten duplicated Maltase genes. We examined the levels of transcription of the nine of these genes in 36 lines of Drosophila melanogaster collected from a natural population. In the investigated population, the levels of transcription were different between the two dietary carbohydrate sources, glucose and starch. At the transcriptional level, a single Maltase gene, which transcribes the specific Maltase transcripts, worked together with an Amylase gene in the pathway. The three of nine genes responded to carbohydrate changes, and the degree of the response was similar to Amylase gene. Our results suggest that gene duplication could increase capacity of the transcriptional regulation associated with environmental changes.


Assuntos
Proteínas de Drosophila , Duplicação Gênica , Transcrição Genética/fisiologia , alfa-Glucosidases , Amilases/biossíntese , Amilases/genética , Animais , Proteínas de Drosophila/biossíntese , Proteínas de Drosophila/genética , Drosophila melanogaster , Especificidade da Espécie , alfa-Glucosidases/biossíntese , alfa-Glucosidases/genética
13.
Nucleic Acids Res ; 47(5): 2276-2288, 2019 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-30590805

RESUMO

In Drosophila, female development is governed by a single RNA-binding protein, Sex-lethal (Sxl), that controls the expression of key factors involved in dosage compensation, germline homeostasis and the establishment of female morphology and behaviour. Sxl expression in female flies is maintained by an auto-regulatory, positive feedback loop with Sxl controlling splicing of its own mRNA. Until now, it remained unclear how males prevent accidental triggering of the Sxl expression cascade and protect themselves against runaway protein production. Here, we identify the protein Sister-of-Sex-lethal (Ssx) as an inhibitor of Sxl auto-regulatory splicing. Sxl and Ssx have a comparable RNA-binding specificity and compete for binding to RNA regulatory elements present in the Sxl transcript. In cultured Drosophila cells, Sxl-induced changes to alternative splicing can be reverted by the expression of Ssx. Moreover, in adult male flies ablation of the ssx gene results in a low level of productive Sxl mRNA splicing and Sxl protein production in isolated, clonal cell populations. In sum, this demonstrates that Ssx safeguards male animals against Sxl protein production to reinforce a stable, male-specific gene expression pattern.


Assuntos
Processamento Alternativo/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Caracteres Sexuais , Animais , Células Cultivadas , Proteínas de Drosophila/biossíntese , Éxons/genética , Feminino , Perfilação da Expressão Gênica , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/biossíntese , Sequências Reguladoras de Ácido Ribonucleico/genética
14.
Cytoskeleton (Hoboken) ; 75(11): 472-480, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30381895

RESUMO

Parent centrioles are characterized in most organisms by individual morphological traits and have distinct asymmetries that provide different functional properties. By contrast, mother and daughter centrioles are morphologically undistinguishable during Drosophila male gametogenesis. Here we report the presence of previously unrecognized microtubule-based structures that extend into the peripheral cytoplasm of the Drosophila polar spermatocytes at the onset of the first meiosis and are positive for the typical centriolar protein Sas-4 and for the kinesin-like protein Klp10A. These structures have a short lifespan and are no longer found in early apolar spermatocytes. Remarkably, each polar spermatocyte holds only one microtubule-based structure that is associated with one of the sister centriole pairs and specifically with the mother centriole. These findings reveal an inherent asymmetry between the parent centrioles at the onset of male meiosis and also uncover unexpected functional properties between the mother centrioles of the same cells.


Assuntos
Centríolos , Meiose/fisiologia , Microtúbulos/metabolismo , Espermatócitos , Espermatogênese/fisiologia , Animais , Divisão Celular Assimétrica/fisiologia , Linhagem Celular , Centríolos/metabolismo , Proteínas de Drosophila/biossíntese , Drosophila melanogaster , Cinesina/biossíntese , Masculino , Espermatócitos/citologia , Espermatócitos/metabolismo
15.
J Neurosci ; 38(43): 9202-9214, 2018 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-30201766

RESUMO

It was proposed that the Drosophila amnesiac gene (amn) is required for consolidation of aversive memory in the dorsal paired medial (DPM) neurons, a pair of large neurons that broadly innervate the mushroom bodies (MB), the fly center for olfactory learning and memory (Waddell et al., 2000). Yet, a conditional analysis showed that it was not possible to rescue the memory deficit of amnX8 null mutant flies when amn expression was restored only in the adult (DeZazzo et al., 1999), which led the authors to suggest that amn might be involved in the development of brain structures that normally promote adult olfactory memory. To further investigate temporal and spatial requirements of Amnesiac (AMN) peptide in memory, we used RNA interference in combination with conditional drivers. Experiments were conducted either in both sexes, or in either sexes. Our data show that acute modulation of amn expression in adult DPM neurons does not impact memory. We further show that amn expression is required for normal development of DPM neurons. Detailed enhancer trap analyses suggest that amn transcription unit contains two distinct enhancers, one specific of DPM neurons, and the other specific of α/ß MB neurons. This prompted us to investigate extensively the role of AMN in the adult MB. Together, our results demonstrate that amn is acutely required in adult α/ß MB neurons for middle-term and long-term memory. The data thus establish that amn plays two distinct roles. Its expression is required in DPM neurons for their development, and in adult MB for olfactory memory.SIGNIFICANCE STATEMENT The Drosophila amnesiac gene encodes a neuropeptide whose expression was proposed to be required for consolidation of aversive memory in the dorsal paired medial (DPM) neurons, a pair of large neurons that broadly innervate the mushroom bodies (MB), the olfactory memory center. Here, we investigated amnesiac temporal and spatial requirement using conditional tools that allowed us to manipulate its expression in selected neurons. This work leads to a complete reassessment of the role of amnesiac in brain development and memory. We show that amnesiac is required for two distinct processes: for normal development of DPM neurons, and in adult MB for memory.


Assuntos
Proteínas de Drosophila/biossíntese , Consolidação da Memória/fisiologia , Corpos Pedunculados/crescimento & desenvolvimento , Corpos Pedunculados/metabolismo , Neurônios/metabolismo , Neuropeptídeos/biossíntese , Fatores Etários , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/genética , Drosophila melanogaster , Feminino , Masculino , Corpos Pedunculados/química , Neurônios/química , Neuropeptídeos/genética
16.
Mol Syst Biol ; 14(9): e8355, 2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30181144

RESUMO

Embryogenesis relies on instructions provided by spatially organized signaling molecules known as morphogens. Understanding the principles behind morphogen distribution and how cells interpret locally this information remains a major challenge in developmental biology. Here, we introduce morphogen-age measurements as a novel approach to test models of morphogen gradient formation. Using a tandem fluorescent timer as a protein age sensor, we find a gradient of increasing age of Bicoid along the anterior-posterior axis in the early Drosophila embryo. Quantitative analysis of the protein age distribution across the embryo reveals that the synthesis-diffusion-degradation model is the most likely model underlying Bicoid gradient formation, and rules out other hypotheses for gradient formation. Moreover, we show that the timer can detect transitions in the dynamics associated with syncytial cellularization. Our results provide new insight into Bicoid gradient formation and demonstrate how morphogen-age information can complement knowledge about movement, abundance, and distribution, which should be widely applicable to other systems.


Assuntos
Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Embrião não Mamífero/metabolismo , Imunofluorescência/métodos , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/genética , Imagem Óptica/métodos , Transativadores/genética , Animais , Padronização Corporal/genética , Proteínas de Drosophila/biossíntese , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Embrião não Mamífero/citologia , Embrião não Mamífero/diagnóstico por imagem , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Homeodomínio/biossíntese , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Estabilidade Proteica , Transporte Proteico , Proteólise , Transdução de Sinais , Transativadores/biossíntese
17.
PLoS One ; 13(7): e0201317, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30063727

RESUMO

Growth and patterning are coordinated during development to define organ size and shape. The growth, proliferation and differentiation of Drosophila wings are regulated by several conserved signaling pathways. Here, we show that the Salvador-Warts-Hippo (SWH) and Notch pathways converge on an enhancer in the expanded (ex) gene, which also responds to levels of the bHLH transcription factor Daughterless (Da). Separate cis-regulatory elements respond to Salvador-Warts-Hippo (SWH) and Notch pathways, to bHLH proteins, and to unidentified factors that repress ex transcription in the wing pouch and in the proneural region at the anterior wing margin. Senseless, a zinc-finger transcription factor acting in proneural regions, had a negative impact on ex transcription in the proneural region, but the transcriptional repressor Hairy had no effect. Our study suggests that a complex pattern of ex transcription results from integration of a uniform SWH signal with multiple other inputs, rather than from a pattern of SWH signaling.


Assuntos
Proteínas de Drosophila/biossíntese , Discos Imaginais/metabolismo , Proteínas de Membrana/biossíntese , Transdução de Sinais/fisiologia , Transcrição Genética/fisiologia , Asas de Animais/embriologia , Animais , Proteínas de Drosophila/genética , Drosophila melanogaster , Discos Imaginais/citologia , Proteínas de Membrana/genética , Asas de Animais/citologia
18.
Parasite Immunol ; 40(10): e12581, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30107045

RESUMO

The Drosophila imaginal disc growth factors (IDGFs) induce the proliferation of imaginal disc cells and terminate cell proliferation at the end of larval development. However, the participation of Idgf-encoding genes in other physiological processes of Drosophila including the immune response to infection is not fully understood. Here, we show the contribution of Idgf2 and Idgf3 in the Drosophila response to infection with Steinernema carpocapsae nematodes carrying or lacking their mutualistic Xenorhabdus nematophila bacteria (symbiotic or axenic nematodes, respectively). We find that Idgf2 and Idgf3 are upregulated in Drosophila larvae infected with symbiotic or axenic Steinernema and inactivation of Idgf2 confers a survival advantage to Drosophila larvae against axenic nematodes. Inactivation of Idgf2 induces the Imd and Jak/Stat pathways, whereas inactivation of Idgf3 induces the Imd, Toll and Jak/Stat pathways. We also show that inactivation of the Imd pathway receptor PGRP-LE upregulates Idgf2 against Steinernema nematode infection. Finally, we demonstrate that inactivation of Idgf3 induces the recruitment of larval haemocytes in response to Steinernema. Our results indicate that Idgf2 and Idgf3 might be involved in different yet crucial immune functions in the Drosophila antinematode immune response. Similar findings will promote the development of new targets for species-specific pest control strategies.


Assuntos
Proteínas de Drosophila/imunologia , Drosophila/imunologia , Drosophila/parasitologia , Glicoproteínas/imunologia , Infecções por Nematoides/imunologia , Strongyloidea/imunologia , Animais , Proteínas de Drosophila/biossíntese , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Glicoproteínas/biossíntese , Glicoproteínas/genética , Glicoproteínas/metabolismo , Discos Imaginais/metabolismo , Larva/imunologia , Larva/parasitologia , Especificidade da Espécie , Strongyloidea/microbiologia , Simbiose , Xenorhabdus/crescimento & desenvolvimento
19.
Neuron ; 99(4): 768-780.e3, 2018 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-30057203

RESUMO

Drosophila NonA and its mammalian ortholog NONO are members of the Drosophila behavior and human splicing (DBHS) family. NONO also has a strong circadian connection: it associates with the circadian repressor protein PERIOD (PER) and contributes to circadian timekeeping. Here, we investigate NonA, which is required for proper levels of evening locomotor activity as well as a normal free-running period in Drosophila. NonA is associated with the positive transcription factor CLOCK/CYCLE (CLK/CYC), interacts directly with complexin (cpx) pre-mRNA, and upregulates gene expression, including the gene cpx. Downregulation of cpx expression in circadian neurons phenocopies NonA downregulation, whereas cpx overexpression rescues the nonA RNAi phenotypes, indicating that cpx is an important NonA target gene. As the cpx protein contributes to proper neurotransmitter and neuropeptide release in response to calcium, these results and others indicate that this control is important for the normal circadian regulation of locomotor activity.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/biossíntese , Relógios Circadianos/fisiologia , Ritmo Circadiano/fisiologia , Proteínas de Drosophila/biossíntese , Locomoção/fisiologia , Proteínas do Tecido Nervoso/biossíntese , Proteínas Nucleares/biossíntese , Proteínas Adaptadoras de Transporte Vesicular/genética , Animais , Animais Geneticamente Modificados , Drosophila , Proteínas de Drosophila/genética , Masculino , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética
20.
G3 (Bethesda) ; 8(9): 2979-2990, 2018 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-30006413

RESUMO

CORL proteins (known as SKOR in mice, Fussel in humans and fussel in Flybase) are a family of CNS specific proteins related to Sno/Ski oncogenes. Their developmental and adult roles are largely unknown. A Drosophila CORL (dCORL) reporter gene is expressed in all Drosophila insulin-like peptide 2 (dILP2) neurons of the pars intercerebralis (PI) of the larval and adult brain. The transcription factor Drifter is also expressed in the PI in a subset of dCORL and dILP2 expressing neurons and in several non-dILP2 neurons. dCORL mutant virgin adult brains are missing all dILP2 neurons that do not also express Drifter. This phenotype is also seen when expressing dCORL-RNAi in neurosecretory cells of the PI. dCORL mutant virgin adults of both sexes have a significantly shorter lifespan than their parental strain. This longevity defect is completely reversed by mating (lifespan increases over 50% for males and females). Analyses of dCORL mutant mated adult brains revealed a complete rescue of dILP2 neurons without Drifter. Taken together, the data suggest that dCORL participates in a neural network connecting the insulin signaling pathway, longevity and mating. The conserved sequence and CNS specificity of all CORL proteins imply that this network may be operating in mammals.


Assuntos
Proteínas de Drosophila/biossíntese , Regulação da Expressão Gênica/fisiologia , Insulina/metabolismo , Longevidade/fisiologia , Neurônios/metabolismo , Neurossecreção/fisiologia , Animais , Drosophila melanogaster , Feminino , Masculino , Rede Nervosa/citologia , Rede Nervosa/metabolismo , Neurônios/citologia
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