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1.
Nat Commun ; 12(1): 4502, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34301937

RESUMO

Cells in many tissues, such as bone, muscle, and placenta, fuse into syncytia to acquire new functions and transcriptional programs. While it is known that fused cells are specialized, it is unclear whether cell-fusion itself contributes to programmatic-changes that generate the new cellular state. Here, we address this by employing a fusogen-mediated, cell-fusion system to create syncytia from undifferentiated cells. RNA-Seq analysis reveals VSV-G-induced cell fusion precedes transcriptional changes. To gain mechanistic insights, we measure the plasma membrane surface area after cell-fusion and observe it diminishes through increases in endocytosis. Consequently, glucose transporters internalize, and cytoplasmic glucose and ATP transiently decrease. This reduced energetic state activates AMPK, which inhibits YAP1, causing transcriptional-reprogramming and cell-cycle arrest. Impairing either endocytosis or AMPK activity prevents YAP1 inhibition and cell-cycle arrest after fusion. Together, these data demonstrate plasma membrane diminishment upon cell-fusion causes transient nutrient stress that may promote transcriptional-reprogramming independent from extrinsic cues.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Glicoproteínas de Membrana/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Genética/genética , Proteínas do Envelope Viral/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Transporte Biológico , Fusão Celular , Linhagem Celular , Linhagem Celular Tumoral , Células Cultivadas , Células Gigantes/metabolismo , Células HEK293 , Humanos , Glicoproteínas de Membrana/genética , Camundongos , RNA-Seq/métodos , Transdução de Sinais/genética , Fatores de Transcrição/genética , Proteínas do Envelope Viral/genética
2.
Prog Neurobiol ; 199: 101966, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33249090

RESUMO

Reconstructing the genealogy of every cell that makes up an organism remains a long-standing challenge in developmental biology. Besides its relevance for understanding the mechanisms underlying normal and pathological development, resolving the lineage origin of cell types will be crucial to create these types on-demand. Multiple strategies have been deployed towards the problem of lineage tracing, ranging from direct observation to sophisticated genetic approaches. Here we discuss the achievements and limitations of past and current technology. Finally, we speculate about the future of lineage tracing and how to reach the next milestones in the field.

3.
Nat Neurosci ; 23(12): 1618-1628, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32719561

RESUMO

We present CLADES (cell lineage access driven by an edition sequence), a technology for cell lineage studies based on CRISPR-Cas9 techniques. CLADES relies on a system of genetic switches to activate and inactivate reporter genes in a predetermined order. Targeting CLADES to progenitor cells allows the progeny to inherit a sequential cascade of reporters, thereby coupling birth order to reporter expression. This system, which can also be temporally induced by heat shock, enables the temporal resolution of lineage development and can therefore be used to deconstruct an extended cell lineage by tracking the reporters expressed in the progeny. When targeted to the germ line, the same cascade progresses across animal generations, predominantly marking each generation with the corresponding combination of reporters. CLADES therefore offers an innovative strategy for making programmable cascades of genes that can be used for genetic manipulation or to record serial biological events.


Assuntos
Linhagem da Célula/genética , Animais , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Reparo do DNA , Drosophila melanogaster , Técnicas de Introdução de Genes , Genes Reporter/genética , Proteínas de Choque Térmico/genética , Células-Tronco Pluripotentes Induzidas , Edição de RNA , Ativação Transcricional , Peixe-Zebra
4.
Development ; 147(11)2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32467238

RESUMO

Gene targeting is an incredibly valuable technique. Sometimes, however, it can also be extremely challenging for various intrinsic reasons (e.g. low target accessibility or nature/extent of gene modification). To bypass these barriers, we designed a transgene-based system in Drosophila that increases the number of independent gene targeting events while at the same time enriching for correctly targeted progeny. Unfortunately, with particularly challenging gene targeting experiments, our original design yielded numerous false positives. Here, we deliver a much-improved technique, named Enhanced Golic+ (E-Golic+). E-Golic+ incorporates genetic modifications to tighten lethality-based selection while simultaneously boosting efficiency. With E-Golic+, we easily achieve previously unattainable gene targeting. Additionally, we built an E-Golic+-based, high-efficiency genetic pipeline for transgene swapping. We demonstrate its utility by transforming GAL4 enhancer-trap lines into tissue-specific Cas9-expressing lines. Given the superior efficiency, specificity and scalability, E-Golic+ promises to expedite development of additional sophisticated genetic/genomic tools in Drosophila.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Drosophila/metabolismo , Marcação de Genes/métodos , Transgenes/genética , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/metabolismo , Drosophila/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Feminino , Células Germinativas/citologia , Células Germinativas/metabolismo , Masculino , Regiões Promotoras Genéticas , RNA Guia/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
Elife ; 92020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32255422

RESUMO

Wiring a complex brain requires many neurons with intricate cell specificity, generated by a limited number of neural stem cells. Drosophila central brain lineages are a predetermined series of neurons, born in a specific order. To understand how lineage identity translates to neuron morphology, we mapped 18 Drosophila central brain lineages. While we found large aggregate differences between lineages, we also discovered shared patterns of morphological diversification. Lineage identity plus Notch-mediated sister fate govern primary neuron trajectories, whereas temporal fate diversifies terminal elaborations. Further, morphological neuron types may arise repeatedly, interspersed with other types. Despite the complexity, related lineages produce similar neuron types in comparable temporal patterns. Different stem cells even yield two identical series of dopaminergic neuron types, but with unrelated sister neurons. Together, these phenomena suggest that straightforward rules drive incredible neuronal complexity, and that large changes in morphology can result from relatively simple fating mechanisms.


Assuntos
Encéfalo/fisiologia , Linhagem da Célula , Drosophila melanogaster/citologia , Células-Tronco Neurais/citologia , Neurogênese , Animais , Encéfalo/citologia , Drosophila melanogaster/genética , Larva , Neurônios/citologia
6.
Nucleic Acids Res ; 48(8): 4344-4356, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32187363

RESUMO

The genome is the blueprint for an organism. Interrogating the genome, especially locating critical cis-regulatory elements, requires deletion analysis. This is conventionally performed using synthetic constructs, making it cumbersome and non-physiological. Thus, we created Cas9-mediated Arrayed Mutagenesis of Individual Offspring (CAMIO) to achieve comprehensive analysis of a targeted region of native DNA. CAMIO utilizes CRISPR that is spatially restricted to generate independent deletions in the intact Drosophila genome. Controlled by recombination, a single guide RNA is stochastically chosen from a set targeting a specific DNA region. Combining two sets increases variability, leading to either indels at 1-2 target sites or inter-target deletions. Cas9 restriction to male germ cells elicits autonomous double-strand-break repair, consequently creating offspring with diverse mutations. Thus, from a single population cross, we can obtain a deletion matrix covering a large expanse of DNA at both coarse and fine resolution. We demonstrate the ease and power of CAMIO by mapping 5'UTR sequences crucial for chinmo's post-transcriptional regulation.


Assuntos
Sistemas CRISPR-Cas , Drosophila/genética , Edição de Genes , Mutagênese , Regiões 5' não Traduzidas , Animais , Animais Geneticamente Modificados , Proteína 9 Associada à CRISPR , Proteínas de Drosophila/genética , Genoma de Inseto , Mutação INDEL , Masculino , Proteínas do Tecido Nervoso/genética , Espermatozoides/metabolismo
7.
Biol Open ; 9(5)2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32205310

RESUMO

During Drosophila and vertebrate brain development, the conserved transcription factor Prospero/Prox1 is an important regulator of the transition between proliferation and differentiation. Prospero level is low in neural stem cells and their immediate progeny, but is upregulated in larval neurons and it is unknown how this process is controlled. Here, we use single molecule fluorescent in situ hybridisation to show that larval neurons selectively transcribe a long prospero mRNA isoform containing a 15 kb 3' untranslated region, which is bound in the brain by the conserved RNA-binding protein Syncrip/hnRNPQ. Syncrip binding increases the stability of the long prospero mRNA isoform, which allows an upregulation of Prospero protein production. Adult flies selectively lacking the long prospero isoform show abnormal behaviour that could result from impaired locomotor or neurological activity. Our findings highlight a regulatory strategy involving alternative polyadenylation followed by differential post-transcriptional regulation.This article has an associated First Person interview with the first author of the paper.

8.
Open Biol ; 9(12): 190229, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31822210

RESUMO

The first meeting exclusively dedicated to the 'High-throughput dense reconstruction of cell lineages' took place at Janelia Research Campus (Howard Hughes Medical Institute) from 14 to 18 April 2019. Organized by Tzumin Lee, Connie Cepko, Jorge Garcia-Marques and Isabel Espinosa-Medina, this meeting echoed the recent eruption of new tools that allow the reconstruction of lineages based on the phylogenetic analysis of DNA mutations induced during development. Combined with single-cell RNA sequencing, these tools promise to solve the lineage of complex model organisms at single-cell resolution. Here, we compile the conference consensus on the technological and computational challenges emerging from the use of the new strategies, as well as potential solutions.


Assuntos
Linhagem da Célula/genética , Rastreamento de Células , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Imagem Molecular , Animais , Sistemas CRISPR-Cas , Rastreamento de Células/métodos , Biologia Computacional , Código de Barras de DNA Taxonômico , Perfilação da Expressão Gênica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Imagem Molecular/métodos , Mutação , Filogenia , Análise de Célula Única/métodos
9.
Elife ; 82019 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-31545163

RESUMO

Temporal patterning is a seminal method of expanding neuronal diversity. Here we unravel a mechanism decoding neural stem cell temporal gene expression and transforming it into discrete neuronal fates. This mechanism is characterized by hierarchical gene expression. First, Drosophila neuroblasts express opposing temporal gradients of RNA-binding proteins, Imp and Syp. These proteins promote or inhibit chinmo translation, yielding a descending neuronal gradient. Together, first and second-layer temporal factors define a temporal expression window of BTB-zinc finger nuclear protein, Mamo. The precise temporal induction of Mamo is achieved via both transcriptional and post-transcriptional regulation. Finally, Mamo is essential for the temporally defined, terminal identity of α'/ß' mushroom body neurons and identity maintenance. We describe a straightforward paradigm of temporal fate specification where diverse neuronal fates are defined via integrating multiple layers of gene regulation. The neurodevelopmental roles of orthologous/related mammalian genes suggest a fundamental conservation of this mechanism in brain development.


Assuntos
Encéfalo/crescimento & desenvolvimento , Diferenciação Celular , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Células-Tronco Neurais/fisiologia , Neurônios/fisiologia , Fatores de Transcrição/metabolismo , Animais , Drosophila , Perfilação da Expressão Gênica
10.
Neuron ; 104(2): 227-238.e7, 2019 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-31395429

RESUMO

Gaining independent genetic access to discrete cell types is critical to interrogate their biological functions as well as to deliver precise gene therapy. Transcriptomics has allowed us to profile cell populations with extraordinary precision, revealing that cell types are typically defined by a unique combination of genetic markers. Given the lack of adequate tools to target cell types based on multiple markers, most cell types remain inaccessible to genetic manipulation. Here we present CaSSA, a platform to create unlimited genetic switches based on CRISPR/Cas9 (Ca) and the DNA repair mechanism known as single-strand annealing (SSA). CaSSA allows engineering of independent genetic switches, each responding to a specific gRNA. Expressing multiple gRNAs in specific patterns enables multiplex cell-type-specific manipulations and combinatorial genetic targeting. CaSSA is a new genetic tool that conceptually works as an unlimited number of recombinases and will facilitate genetic access to cell types in diverse organisms.


Assuntos
Sistemas CRISPR-Cas , Reparo do DNA , Marcação de Genes/métodos , Animais , Drosophila , Técnicas Genéticas , RNA Guia , Recombinases/genética , Peixe-Zebra
11.
Elife ; 82019 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-30912745

RESUMO

The vast majority of the adult fly ventral nerve cord is composed of 34 hemilineages, which are clusters of lineally related neurons. Neurons in these hemilineages use one of the three fast-acting neurotransmitters (acetylcholine, GABA, or glutamate) for communication. We generated a comprehensive neurotransmitter usage map for the entire ventral nerve cord. We did not find any cases of neurons using more than one neurotransmitter, but found that the acetylcholine specific gene ChAT is transcribed in many glutamatergic and GABAergic neurons, but these transcripts typically do not leave the nucleus and are not translated. Importantly, our work uncovered a simple rule: All neurons within a hemilineage use the same neurotransmitter. Thus, neurotransmitter identity is acquired at the stem cell level. Our detailed transmitter- usage/lineage identity map will be a great resource for studying the developmental basis of behavior and deciphering how neuronal circuits function to regulate behavior.


Assuntos
Linhagem da Célula/fisiologia , Sistema Nervoso Central/citologia , Sistema Nervoso Central/crescimento & desenvolvimento , Neurônios/metabolismo , Neurotransmissores/metabolismo , Animais , Diferenciação Celular , Drosophila , Células-Tronco/fisiologia
12.
Curr Opin Neurobiol ; 56: 24-32, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30500514

RESUMO

A complex nervous system requires precise numbers of various neuronal types produced with exquisite spatiotemporal control. This striking diversity is generated by a limited number of neural stem cells (NSC), where spatial and temporal patterning intersect. Drosophila is a genetically tractable model system that has significant advantages for studying stem cell biology and neuronal fate specification. Here we review the latest findings in the rich literature of temporal patterning of neuronal identity in the Drosophila central nervous system. Rapidly changing consecutive transcription factors expressed in NSCs specify short series of neurons with considerable differences. More slowly progressing changes are orchestrated by NSC intrinsic temporal factor gradients which integrate extrinsic signals to coordinate nervous system and organismal development.


Assuntos
Células-Tronco Neurais , Animais , Sistema Nervoso Central , Proteínas de Drosophila , Drosophila melanogaster , Neurônios
13.
Development ; 145(11)2018 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-29764857

RESUMO

Macroglial cells in the central nervous system exhibit regional specialization and carry out region-specific functions. Diverse glial cells arise from specific progenitors in specific spatiotemporal patterns. This raises an interesting possibility that glial precursors with distinct developmental fates exist that govern region-specific gliogenesis. Here, we have mapped the glial progeny produced by the Drosophila type II neuroblasts, which, like vertebrate radial glia cells, yield both neurons and glia via intermediate neural progenitors (INPs). Distinct type II neuroblasts produce different characteristic sets of glia. A single INP can make both astrocyte-like and ensheathing glia, which co-occupy a relatively restrictive subdomain. Blocking apoptosis uncovers further lineage distinctions in the specification, proliferation and survival of glial precursors. Both the switch from neurogenesis to gliogenesis and the subsequent glial expansion depend on Notch signaling. Taken together, lineage origins preconfigure the development of individual glial precursors with involvement of serial Notch actions in promoting gliogenesis.


Assuntos
Encéfalo/embriologia , Proteínas de Drosophila/metabolismo , Drosophila/embriologia , Células-Tronco Neurais/citologia , Neurogênese/fisiologia , Receptores Notch/metabolismo , Animais , Apoptose/fisiologia , Astrócitos/citologia , Encéfalo/citologia , Linhagem da Célula/fisiologia , Proliferação de Células/fisiologia , Neurônios/citologia
14.
Proc Natl Acad Sci U S A ; 114(38): E8091-E8099, 2017 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-28874527

RESUMO

In their classic experiments, Olds and Milner showed that rats learn to lever press to receive an electric stimulus in specific brain regions. This led to the identification of mammalian reward centers. Our interest in defining the neuronal substrates of reward perception in the fruit fly Drosophila melanogaster prompted us to develop a simpler experimental approach wherein flies could implement behavior that induces self-stimulation of specific neurons in their brains. The high-throughput assay employs optogenetic activation of neurons when the fly occupies a specific area of a behavioral chamber, and the flies' preferential occupation of this area reflects their choosing to experience optogenetic stimulation. Flies in which neuropeptide F (NPF) neurons are activated display preference for the illuminated side of the chamber. We show that optogenetic activation of NPF neuron is rewarding in olfactory conditioning experiments and that the preference for NPF neuron activation is dependent on NPF signaling. Finally, we identify a small subset of NPF-expressing neurons located in the dorsomedial posterior brain that are sufficient to elicit preference in our assay. This assay provides the means for carrying out unbiased screens to map reward neurons in flies.


Assuntos
Proteínas de Drosophila/metabolismo , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Transdução de Sinais/fisiologia , Animais , Proteínas de Drosophila/genética , Drosophila melanogaster , Neuropeptídeos/genética
15.
Development ; 144(19): 3454-3464, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28851709

RESUMO

The termination of the proliferation of Drosophila neural stem cells, also known as neuroblasts (NBs), requires a 'decommissioning' phase that is controlled in a lineage-specific manner. Most NBs, with the exception of those of the mushroom body (MB), are decommissioned by the ecdysone receptor and mediator complex, causing them to shrink during metamorphosis, followed by nuclear accumulation of Prospero and cell cycle exit. Here, we demonstrate that the levels of Imp and Syp RNA-binding proteins regulate NB decommissioning. Descending Imp and ascending Syp expression have been shown to regulate neuronal temporal fate. We show that Imp levels decline slower in the MB than in other central brain NBs. MB NBs continue to express Imp into pupation, and the presence of Imp prevents decommissioning partly by inhibiting the mediator complex. Late-larval induction of transgenic Imp prevents many non-MB NBs from decommissioning in early pupae. Moreover, the presence of abundant Syp in aged NBs permits Prospero accumulation that, in turn, promotes cell cycle exit. Together, our results reveal that progeny temporal fate and progenitor decommissioning are co-regulated in protracted neuronal lineages.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/metabolismo , Células-Tronco Neurais/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Animais Geneticamente Modificados , Núcleo Celular/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Larva/metabolismo , Complexo Mediador/metabolismo , Modelos Biológicos , Corpos Pedunculados/citologia , Corpos Pedunculados/metabolismo , Células-Tronco Neurais/citologia , Ligação Proteica , Pupa/metabolismo , Proteínas de Ligação a RNA/genética
16.
Curr Biol ; 27(9): 1303-1313, 2017 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-28434858

RESUMO

Building a sizable, complex brain requires both cellular expansion and diversification. One mechanism to achieve these goals is production of multiple transiently amplifying intermediate neural progenitors (INPs) from a single neural stem cell. Like mammalian neural stem cells, Drosophila type II neuroblasts utilize INPs to produce neurons and glia. Within a given lineage, the consecutively born INPs produce morphologically distinct progeny, presumably due to differential inheritance of temporal factors. To uncover the underlying temporal fating mechanisms, we profiled type II neuroblasts' transcriptome across time. Our results reveal opposing temporal gradients of Imp and Syp RNA-binding proteins (descending and ascending, respectively). Maintaining high Imp throughout serial INP production expands the number of neurons and glia with early temporal fate at the expense of cells with late fate. Conversely, precocious upregulation of Syp reduces the number of cells with early fate. Furthermore, we reveal that the transcription factor Seven-up initiates progression of the Imp/Syp gradients. Interestingly, neuroblasts that maintain initial Imp/Syp levels can still yield progeny with a small range of early fates. We therefore propose that the Seven-up-initiated Imp/Syp gradients create coarse temporal windows within type II neuroblasts to pattern INPs, which subsequently undergo fine-tuned subtemporal patterning.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Neurais/metabolismo , Proteínas de Ligação a RNA/metabolismo , Receptores de Esteroides/metabolismo , Animais , Ciclo Celular , Linhagem da Célula , Proliferação de Células , Drosophila melanogaster/metabolismo , Perfilação da Expressão Gênica , Neurogênese , Neurônios/citologia , Neurônios/metabolismo , Fator de Células-Tronco/metabolismo
17.
Curr Biol ; 27(2): R77-R82, 2017 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-28118595

RESUMO

A complex brain consists of multiple intricate neural networks assembled from distinct sets of input and output neurons as well as region-specific local interneurons. Within a given anatomical set, there exist diverse neuronal types that can vary in morphology, neural physiology, and modes of neurotransmission. The genetic programs that guide specification of neuronal types during neurogenesis preconfigure the brain. This is best demonstrated in the Drosophila central brain, which is composed of ∼100 pairs of individually tailored neuronal lineages. Each neuronal lineage (the neurons/glia produced from a single stem cell) can contain multiple morphological classes of neurons that can consist of many analogous neuronal types. The detailed patterns of neuronal diversification are lineage-specific and can differ drastically even among neighboring neuronal lineages. Furthermore, the interrelationships between neuronal lineages and neural networks are complex. These phenomena underscore the importance of tracking all neuronal lineages in understanding brain development and evolution.


Assuntos
Linhagem da Célula , Drosophila/embriologia , Células-Tronco Neurais/citologia , Neurônios/citologia , Animais , Encéfalo/embriologia , Encéfalo/fisiologia , Drosophila/citologia , Drosophila/fisiologia , Células-Tronco Neurais/fisiologia , Neurônios/fisiologia
18.
Curr Biol ; 26(19): 2583-2593, 2016 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-27618265

RESUMO

The morphology and physiology of neurons are directed by developmental decisions made within their lines of descent from single stem cells. Distinct stem cells may produce neurons having shared properties that define their cell class, such as the type of secreted neurotransmitter. The relationship between cell class and lineage is complex. Here we developed the transgenic cell class-lineage intersection (CLIn) system to assign cells of a particular class to specific lineages within the Drosophila brain. CLIn also enables birth-order analysis and genetic manipulation of particular cell classes arising from particular lineages. We demonstrated the power of CLIn in the context of the eight central brain type II lineages, which produce highly diverse progeny through intermediate neural progenitors. We mapped 18 dopaminergic neurons from three distinct clusters to six type II lineages that show lineage-characteristic neurite trajectories. In addition, morphologically distinct dopaminergic neurons are produced within a given lineage, and they arise in an invariant sequence. We also identified type II lineages that produce doublesex- and fruitless-expressing neurons and examined whether female-specific apoptosis in these lineages accounts for the lower number of these neurons in the female brain. Blocking apoptosis in these lineages resulted in more cells in both sexes with males still carrying more cells than females. This argues that sex-specific stem cell fate together with differential progeny apoptosis contribute to the final sexual dimorphism.


Assuntos
Encéfalo/fisiologia , Linhagem da Célula , Drosophila melanogaster/fisiologia , Animais , Animais Geneticamente Modificados , Apoptose , Encéfalo/crescimento & desenvolvimento , Drosophila melanogaster/crescimento & desenvolvimento , Feminino , Masculino , Caracteres Sexuais
19.
Development ; 143(3): 411-21, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26700685

RESUMO

A brain consists of numerous distinct neurons arising from a limited number of progenitors, called neuroblasts in Drosophila. Each neuroblast produces a specific neuronal lineage. To unravel the transcriptional networks that underlie the development of distinct neuroblast lineages, we marked and isolated lineage-specific neuroblasts for RNA sequencing. We labeled particular neuroblasts throughout neurogenesis by activating a conditional neuroblast driver in specific lineages using various intersection strategies. The targeted neuroblasts were efficiently recovered using a custom-built device for robotic single-cell picking. Transcriptome analysis of mushroom body, antennal lobe and type II neuroblasts compared with non-selective neuroblasts, neurons and glia revealed a rich repertoire of transcription factors expressed among neuroblasts in diverse patterns. Besides transcription factors that are likely to be pan-neuroblast, many transcription factors exist that are selectively enriched or repressed in certain neuroblasts. The unique combinations of transcription factors present in different neuroblasts may govern the diverse lineage-specific neuron fates.


Assuntos
Linhagem da Célula/genética , Drosophila melanogaster/genética , Marcação de Genes , Neurônios/citologia , Robótica , Transcriptoma/genética , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Regulação da Expressão Gênica no Desenvolvimento , Análise de Sequência de RNA , Análise de Célula Única , Fatores de Transcrição/metabolismo
20.
Science ; 350(6258): 317-20, 2015 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-26472907

RESUMO

Neural stem cells show age-dependent developmental potentials, as evidenced by their production of distinct neuron types at different developmental times. Drosophila neuroblasts produce long, stereotyped lineages of neurons. We searched for factors that could regulate neural temporal fate by RNA-sequencing lineage-specific neuroblasts at various developmental times. We found that two RNA-binding proteins, IGF-II mRNA-binding protein (Imp) and Syncrip (Syp), display opposing high-to-low and low-to-high temporal gradients with lineage-specific temporal dynamics. Imp and Syp promote early and late fates, respectively, in both a slowly progressing and a rapidly changing lineage. Imp and Syp control neuronal fates in the mushroom body lineages by regulating the temporal transcription factor Chinmo translation. Together, the opposing Imp/Syp gradients encode stem cell age, specifying multiple cell fates within a lineage.


Assuntos
Linhagem da Célula , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/crescimento & desenvolvimento , Células-Tronco Neurais/citologia , Neurogênese/fisiologia , Neurônios/citologia , Proteínas de Ligação a RNA/fisiologia , Animais , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Corpos Pedunculados/citologia , Corpos Pedunculados/crescimento & desenvolvimento , Proteínas do Tecido Nervoso/metabolismo , Neurogênese/genética , Proteínas de Ligação a RNA/genética , Análise de Sequência de RNA
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