RESUMO
Hormones regulate behavior either through activational effects that facilitate the acute expression of specific behaviors or through organizational effects that shape the development of the nervous system thereby altering adult behavior. Much research has implicated the neuropeptide oxytocin (OXT) in acute modulation of various aspects of social behaviors across vertebrate species, and OXT signaling is associated with the developmental social deficits observed in autism spectrum disorders (ASDs); however, little is known about the role of OXT in the neurodevelopment of the social brain. We show that perturbation of OXT neurons during early zebrafish development led to a loss of dopaminergic neurons, associated with visual processing and reward, and blunted the neuronal response to social stimuli in the adult brain. Ultimately, adult fish whose OXT neurons were ablated in early life, displayed altered functional connectivity within social decision-making brain nuclei both in naive state and in response to social stimulus and became less social. We propose that OXT neurons have an organizational role, namely, to shape forebrain neuroarchitecture during development and to acquire an affiliative response toward conspecifics.SIGNIFICANCE STATEMENT Social behavior is developed over the lifetime of an organism and the neuropeptide oxytocin (OXT) modulates social behaviors across vertebrate species, and is associated with neuro-developmental social deficits such as autism. However, whether OXT plays a role in the developmental maturation of neural systems that are necessary for social behavior remains poorly explored. We show that proper behavioral and neural response to social stimuli depends on a developmental process orchestrated by OXT neurons. Animals whose OXT system is ablated in early life show blunted neuronal and behavioral responses to social stimuli as well as wide ranging disruptions in the functional connectivity of the social brain. We provide a window into the mechanisms underlying OXT-dependent developmental processes that implement adult sociality.
Assuntos
Neurônios/metabolismo , Ocitocina/antagonistas & inibidores , Ocitocina/metabolismo , Comportamento Social , Animais , Animais Geneticamente Modificados , Feminino , Masculino , Metronidazol/toxicidade , Neurônios/efeitos dos fármacos , Ocitocina/genética , Receptores de Ocitocina/antagonistas & inibidores , Receptores de Ocitocina/genética , Receptores de Ocitocina/metabolismo , Peixe-ZebraRESUMO
To maintain body homeostasis, endocrine systems must detect and integrate blood-borne peripheral signals. This is mediated by fenestrae, specialized permeable pores in the endothelial membrane. Plasmalemma vesicle-associated protein (Plvap) is located in the fenestral diaphragm and is thought to play a role in the passage of proteins through the fenestrae. However, this suggested function has yet to be demonstrated directly. We studied the development of fenestrated capillaries in the hypophysis, a major neuroendocrine interface between the blood and brain. Using a transgenic biosensor to visualize the vascular excretion of the genetically tagged plasma protein DBP-EGFP, we show that the developmental acquisition of vascular permeability coincides with differential expression of zebrafish plvap orthologs in the hypophysis versus brain. Ultrastructural analysis revealed that plvapb mutants display deficiencies in fenestral diaphragms and increased density of hypophyseal fenestrae. Measurements of DBP-EGFP extravasation in plvapb mutants provided direct proof that Plvap limits the rate of blood-borne protein passage through fenestrated endothelia. We present the regulatory role of Plvap in the development of blood-borne protein detection machinery at a neuroendocrine interface through which hormones are released to the general circulation.
Assuntos
Permeabilidade Capilar/fisiologia , Endotélio Vascular/metabolismo , Proteínas de Membrana/metabolismo , Hipófise/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Proteínas de Membrana/genética , Mutação , Transporte Proteico/fisiologia , Peixe-Zebra/genéticaRESUMO
Class-B1 G-protein-coupled receptors (GPCRs) are an important family of clinically relevant drug targets that remain difficult to investigate via high-throughput screening and in animal models. Here, we engineered PAClight1P78A, a novel genetically encoded sensor based on a class-B1 GPCR (the human PAC1 receptor, hmPAC1R) endowed with high dynamic range (ΔF/F0 = 1100%), excellent ligand selectivity, and rapid activation kinetics (τON = 1.15 s). To showcase the utility of this tool for in vitro applications, we thoroughly characterized and compared its expression, brightness and performance between PAClight1P78A-transfected and stably expressing cells. Demonstrating its use in animal models, we show robust expression and fluorescence responses upon exogenous ligand application ex vivo and in vivo in mice, as well as in living zebrafish larvae. Thus, the new GPCR-based sensor can be used for a wide range of applications across the life sciences empowering both basic research and drug development efforts.
Assuntos
Peixe-Zebra , Animais , Peixe-Zebra/metabolismo , Peixe-Zebra/genética , Camundongos , Humanos , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/genética , Células HEK293 , Técnicas Biossensoriais/métodos , Engenharia de Proteínas/métodos , LigantesRESUMO
Corticotrophs are intermediaries in the hypothalamic-pituitary-adrenal (HPA) axis, which plays a crucial role in stress response in vertebrates. The HPA axis displays an intricate mode of negative feedback regulation, whereby the peripheral effector, cortisol inhibits the secretion of its upstream regulator, adrenocorticotropic hormone (ACTH) from proopiomelanocortin (POMC)-expressing cells in the pituitary. While the feedback regulation of the HPA axis is well characterized in the adult organism, the effect of feedback regulation on the development of corticotrophs is poorly understood. Here, we studied the effect of glucocorticoids on the development of POMC-expressing cells in the zebrafish pituitary. The development of POMC cells showed a steady increase in numbers between 2-6 days post fertilization. Inhibition of endogenous glucocorticoid synthesis resulted in an increase in POMC cell number due to reduced developmental feedback inhibition of cortisol on POMC cells. Conversely, addition of exogenous dexamethasone at a critical developmental window led to a decrease in corticotroph cell number, mimicking greater feedback control due to increased cortisol levels. Finally, developmental dysregulation of ACTH levels resulted in impaired anxiety-like and stress-coping behaviours. Hence, we identified a sensitive developmental window for the effect of glucocorticoids on corticotrophs and demonstrate the downstream effect on stress-responsive behaviour.
Assuntos
Glucocorticoides , Animais , Hormônio Adrenocorticotrópico/metabolismo , Corticotrofos/metabolismo , Glucocorticoides/farmacologia , Hidrocortisona , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Pró-Opiomelanocortina/metabolismo , Peixe-Zebra , Estresse FisiológicoRESUMO
Individuals in a population respond differently to stressful situations. While resilient individuals recover efficiently, others are susceptible to the same stressors. However, it remains challenging to determine if resilience is established as a trait during development or acquired later in life. Using a behavioral paradigm in zebrafish larvae, we show that resilience is a stable and heritable trait, which is determined and exhibited early in life. Resilient larvae show unique stress-induced transcriptional response, and larvae with mutations in resilience-associated genes, such as neuropeptide Y and miR218, are less resilient. Transcriptome analysis shows that resilient larvae downregulate multiple factors of the innate immune complement cascade in response to stress. Perturbation of critical complement factors leads to an increase in resilience. We conclude that resilience is established as a stable trait early during development and that neuropeptides and the complement pathway play positive and negative roles in determining resilience, respectively.
Assuntos
Resiliência Psicológica , Animais , Estresse Psicológico , Peixe-Zebra , Ativação do ComplementoRESUMO
Emotional contagion is the most ancestral form of empathy. We tested to what extent the proximate mechanisms of emotional contagion are evolutionarily conserved by assessing the role of oxytocin, known to regulate empathic behaviors in mammals, in social fear contagion in zebrafish. Using oxytocin and oxytocin receptor mutants, we show that oxytocin is both necessary and sufficient for observer zebrafish to imitate the distressed behavior of conspecific demonstrators. The brain regions associated with emotional contagion in zebrafish are homologous to those involved in the same process in rodents (e.g., striatum, lateral septum), receiving direct projections from oxytocinergic neurons located in the pre-optic area. Together, our results support an evolutionary conserved role for oxytocin as a key regulator of basic empathic behaviors across vertebrates.
Assuntos
Comportamento Animal , Empatia , Medo , Ocitocina , Comportamento Social , Peixe-Zebra , Animais , Empatia/efeitos dos fármacos , Empatia/fisiologia , Medo/efeitos dos fármacos , Medo/fisiologia , Ocitocina/farmacologia , Ocitocina/fisiologia , Peixe-Zebra/genética , Receptores de Ocitocina/genética , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologiaRESUMO
The pituitary is the master neuroendocrine gland, which regulates body homeostasis. It consists of the anterior pituitary/adenohypophysis harboring hormones producing cells and the posterior pituitary/neurohypophysis, which relays the passage of hormones from the brain to the periphery. It is accepted that the adenohypophysis originates from the oral ectoderm (Rathke's pouch), whereas the neural ectoderm contributes to the neurohypophysis. Single-cell transcriptomics of the zebrafish pituitary showed that cyp26b1-positive astroglial pituicytes of the neurohypophysis and prop1-positive adenohypophyseal progenitors expressed common markers implying lineage relatedness. Genetic tracing identifies that, in contrast to the prevailing dogma, neural plate precursors of zebrafish (her4.3+) and mouse (Sox1+) contribute to both neurohypophyseal and a subset of adenohypophyseal cells. Pituicyte-derived retinoic-acid-degrading enzyme Cyp26b1 fine-tunes differentiation of prop1+ progenitors into hormone-producing cells. These results challenge the notion that adenohypophyseal cells are exclusively derived from non-neural ectoderm and demonstrate that crosstalk between neuro- and adeno-hypophyseal cells affects differentiation of pituitary cells.
Assuntos
Neuro-Hipófise , Camundongos , Animais , Peixe-Zebra , Placa Neural , Ácido Retinoico 4 Hidroxilase , HormôniosRESUMO
Fenestrated and blood-brain barrier (BBB)-forming endothelial cells constitute major brain capillaries, and this vascular heterogeneity is crucial for region-specific neural function and brain homeostasis. How these capillary types emerge in a brain region-specific manner and subsequently establish intra-brain vascular heterogeneity remains unclear. Here, we performed a comparative analysis of vascularization across the zebrafish choroid plexuses (CPs), circumventricular organs (CVOs), and retinal choroid, and show common angiogenic mechanisms critical for fenestrated brain capillary formation. We found that zebrafish deficient for Gpr124, Reck, or Wnt7aa exhibit severely impaired BBB angiogenesis without any apparent defect in fenestrated capillary formation in the CPs, CVOs, and retinal choroid. Conversely, genetic loss of various Vegf combinations caused significant disruptions in Wnt7/Gpr124/Reck signaling-independent vascularization of these organs. The phenotypic variation and specificity revealed heterogeneous endothelial requirements for Vegfs-dependent angiogenesis during CP and CVO vascularization, identifying unexpected interplay of Vegfc/d and Vegfa in this process. Mechanistically, expression analysis and paracrine activity-deficient vegfc mutant characterization suggest that endothelial cells and non-neuronal specialized cell types present in the CPs and CVOs are major sources of Vegfs responsible for regionally restricted angiogenic interplay. Thus, brain region-specific presentations and interplay of Vegfc/d and Vegfa control emergence of fenestrated capillaries, providing insight into the mechanisms driving intra-brain vascular heterogeneity and fenestrated vessel formation in other organs.
Assuntos
Células Endoteliais , Peixe-Zebra , Animais , Barreira Hematoencefálica/fisiologia , Encéfalo/irrigação sanguínea , Capilares , Células Endoteliais/fisiologia , Neovascularização Fisiológica/genética , Peixe-Zebra/genéticaRESUMO
The transcriptional coactivator PGC-1α is a key regulator of cellular energy expenditure in peripheral tissues. Recent studies report that PGC-1α-null mice develop late-onset obesity and that the neuronal inactivation of PGC-1α causes increased food intake. However, the exact role of PGC-1α in the CNS remains unclear. Here we show that PGC-1α directly regulates the expression of the hypothalamic neuropeptide oxytocin, a known central regulator of appetite. We developed a unique genetic approach in the zebrafish, allowing us to monitor and manipulate PGC-1α activity in oxytocinergic neurons. We found that PGC-1α is coexpressed with oxytocin in the zebrafish hypothalamus. Targeted knockdown of the zebrafish PGC-1α gene activity caused a marked decrease in oxytocin mRNA levels and inhibited the expression of a transgenic GFP reporter driven by the oxytocin promoter. The effect of PGC-1α loss of function on oxytocin gene activity was rescued by tissue-specific re-expression of either PGC-1α or oxytocin precursor in zebrafish oxytocinergic neurons. PGC-1α activated the oxytocin promoter in a heterologous cell culture system, and overexpression of PGC-1α induced ectopic expression of oxytocin in muscles and neurons. Finally, PGC-1α forms an in vivo complex with the oxytocin promoter in fed but not fasted animals. These findings demonstrate that PGC-1α is both necessary and sufficient for the production of oxytocin, implicating hypothalamic PGC-1α in the direct activation of a hypothalamic hormone known to control energy intake.
Assuntos
Proteínas de Choque Térmico/metabolismo , Hipotálamo/citologia , Neurônios/metabolismo , Ocitocina/metabolismo , Fatores de Transcrição/metabolismo , Análise de Variância , Animais , Animais Geneticamente Modificados , Linhagem Celular Transformada , Imunoprecipitação da Cromatina/métodos , Biologia Computacional , Embrião não Mamífero , Jejum/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Comportamento Alimentar/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Choque Térmico/genética , Humanos , Hipotálamo/metabolismo , Masculino , Camundongos , Neurônios/efeitos dos fármacos , Oligodesoxirribonucleotídeos Antissenso/farmacologia , Ocitocina/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , RNA Mensageiro , Fatores de Transcrição/genética , Transfecção/métodos , Peixe-ZebraRESUMO
Hypothalamic gonadotropin-releasing hormone (GnRH) neurons control pituitary gonadotropin secretion and gametogenesis. In the course of development, these neurons migrate from the olfactory placode to the hypothalamus. The precise molecular mechanism of this neuronal migration is unclear. Here, we investigated whether the chemokine receptor, Cxcr4b, and its cognate ligand, Cxcl12a, are required for proper migration of GnRH3 neurons in zebrafish. Deviated GnRH3 axonal projections and neuronal migration were detected in larvae that carry a homozygote cxcr4b mutation. Similarly, knockdown of Cxcr4b or Cxcl12a led to the appearance of abnormal GnRH3 axonal projections and cell migration, including absence of the characteristic lateral crossing of GnRH3 axons at the anterior commissure and optic chiasm. Double-labeling analysis has shown that cxcr4b and cxcl12a are expressed along the GnRH3 migration pathway (i.e. olfactory placode, terminal nerve and the optic chiasm). The results of this study suggest that the Cxcl12a-Cxcr4b ligand-receptor pair are involved in the migration of GnRH3 neurons in zebrafish, and are therefore crucial for the development of this system.
Assuntos
Quimiocina CXCL12/fisiologia , Hormônio Liberador de Gonadotropina/metabolismo , Prosencéfalo/embriologia , Prosencéfalo/crescimento & desenvolvimento , Ácido Pirrolidonocarboxílico/análogos & derivados , Receptores CXCR4/fisiologia , Transdução de Sinais , Proteínas de Peixe-Zebra/fisiologia , Peixe-Zebra/fisiologia , Animais , Movimento Celular/genética , Movimento Celular/fisiologia , Quimiocina CXCL12/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Imuno-Histoquímica , Hibridização In Situ , Mutação , Ácido Pirrolidonocarboxílico/metabolismo , Receptores CXCR4/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento , Proteínas de Peixe-Zebra/genéticaRESUMO
The neurohypophysis (NH), located at the posterior lobe of the pituitary, is a major neuroendocrine tissue, which mediates osmotic balance, blood pressure, reproduction, and lactation by means of releasing the neurohormones oxytocin (OXT) and arginine-vasopressin (AVP) from the brain into the peripheral blood circulation. The major cellular components of the NH are hypothalamic axonal termini, fenestrated endothelia and pituicytes, the resident astroglia. However, despite the physiological importance of the NH, the exact molecular signature defining neurohypophyseal cell types and in particular the pituicytes, remains unclear. Using single-cell RNA sequencing (scRNA-Seq), we captured seven distinct cell types in the NH and intermediate lobe (IL) of adult male mouse. We revealed novel pituicyte markers showing higher specificity than previously reported. Bioinformatics analysis demonstrated that pituicyte is an astrocytic cell type whose transcriptome resembles that of tanycyte. Single molecule in situ hybridization revealed spatial organization of the major cell types implying intercellular communications. We present a comprehensive molecular and cellular characterization of neurohypophyseal cell types serving as a valuable resource for further functional research.
Assuntos
Neuro-Hipófise , Animais , Arginina Vasopressina/metabolismo , Astrócitos/metabolismo , Masculino , Camundongos , Neuroglia/metabolismo , Ocitocina , Neuro-Hipófise/metabolismoRESUMO
Social living animals need to recognize the presence of conspecifics in the environment in order to engage in adaptive social interactions. Social cues can be detected through different sensory modalities, including vision. Two main visual features can convey information about the presence of conspecifics: body form and biological motion (BM). Given the role that oxytocin plays in social behavior regulation across vertebrates, particularly in the salience and reward values of social stimuli, we hypothesized that it may also be involved in the modulation of perceptual mechanisms for conspecific detection. Here, using videoplaybacks, we assessed the role of conspecific form and BM in zebrafish social affiliation, and how oxytocin regulates the perception of these cues. We demonstrated that while each visual cue is important for social attraction, BM promotes a higher fish engagement than the static conspecific form alone. Moreover, using a mutant line for one of the two oxytocin receptors, we show that oxytocin signaling is involved in the regulation of BM detection but not conspecific form recognition. In summary, our results indicate that, apart from oxytocin role in the regulation of social behaviors through its effect on higher-order cognitive mechanisms, it may regulate social behavior by modulating very basic perceptual mechanisms underlying the detection of socially-relevant cues.
Assuntos
Comportamento Animal/fisiologia , Comportamento Social , Peixe-Zebra/fisiologia , AnimaisRESUMO
Sociality is a complex phenomenon that involves the individual´s motivation to approach their conspecifics, along with social cognitive functions that enable individuals to interact and survive. The nonapeptide oxytocin (OXT) is known to regulate sociality in many species. However, the role of OXT in specific aspects of sociality is still not well understood. In the present study, we investigated the contribution of the OXT receptor (OXTR) signalling in two different aspects of zebrafish social behaviour: social preference, by measuring their motivation to approach a shoal of conspecifics, and social recognition, by measuring their ability to discriminate between a novel and familiar fish, using a mutant zebrafish lacking a functional OXTR. Although oxtr mutant zebrafish displayed normal attraction to a shoal of conspecifics, they exhibited reduced social recognition. We further investigated whether this effect would be social-domain specific by replacing conspecific fish by objects. Although no differences were observed in object approach, oxtr mutant fish also exhibited impaired object recognition. Our findings suggest that OXTR signalling regulates a more general memory recognition of familiar vs novel entities, not only in social but also in a non-social domain, in zebrafish.
Assuntos
Receptores de Ocitocina/metabolismo , Reconhecimento Psicológico/fisiologia , Transdução de Sinais/fisiologia , Comportamento Social , Animais , Animais Geneticamente Modificados , Feminino , Masculino , Peixe-ZebraRESUMO
The pituitary adenylate cyclase-activating polypeptide receptor (PAC1, also known as ADCYAP1R1) is associated with post-traumatic stress disorder and modulation of stress response in general. Alternative splicing of PAC1 results in multiple gene products, which differ in their mode of signalling and tissue distribution. However, the roles of distinct splice variants in the regulation of stress behavior is poorly understood. Alternative splicing of a short exon, which is known as the "hop cassette", occurs during brain development and in response to stressful challenges. To examine the function of this variant, we generated a splice-specific zebrafish mutant lacking the hop cassette, which we designated 'hopless'. We show that hopless mutant larvae display increased anxiety-like behavior, including reduced dark exploration and impaired habituation to dark exposure. Conversely, adult hopless mutants displayed superior ability to rebound from an acute stressor, as they exhibited reduced anxiety-like responses to an ensuing novelty stress. We propose that the developmental loss of a specific PAC1 splice variant mimics prolonged mild stress exposure, which in the long term, predisposes the organism's stress response towards a resilient phenotype. Our study presents a unique genetic model demonstrating how early-life state of anxiety paradoxically correlates with reduced stress susceptibility in adulthood.
RESUMO
Oxytocin-like peptides have been implicated in the regulation of a wide range of social behaviors across taxa. On the other hand, the social environment, which is composed of conspecifics that may vary in their genotypes, also influences social behavior, creating the possibility for indirect genetic effects. Here, we used a zebrafish oxytocin receptor knockout line to investigate how the genotypic composition of the social environment (Gs) interacts with the oxytocin genotype of the focal individual (Gi) in the regulation of its social behavior. For this purpose, we have raised wild-type or knock-out zebrafish in either wild-type or knock-out shoals and tested different components of social behavior in adults. GixGs effects were detected in some behaviors, highlighting the need to control for GixGs effects when interpreting results of experiments using genetically modified animals, since the genotypic composition of the social environment can either rescue or promote phenotypes associated with specific genes.
Assuntos
Variação Genética , Fenótipo , Receptores de Ocitocina/genética , Comportamento Social , Peixe-Zebra/genética , Animais , Comportamento Animal , Feminino , Técnicas de Inativação de Genes , Genótipo , Masculino , Mutação , Meio SocialRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
The regulation of neuropeptide level at the site of release is essential for proper neurophysiological functions. We focused on a prominent neuropeptide, oxytocin (OXT) in the zebrafish as an in vivo model to visualize and quantify OXT content at the resolution of a single synapse. We found that OXT-loaded synapses were enriched with polymerized actin. Perturbation of actin filaments by either cytochalasin-D or conditional Cofilin expression resulted in decreased synaptic OXT levels. Genetic loss of robo2 or slit3 displayed decreased synaptic OXT content and robo2 mutants displayed reduced mobility of the actin probe Lifeact-EGFP in OXT synapses. Using a novel transgenic reporter allowing real-time monitoring of OXT-loaded vesicles, we show that robo2 mutants display slower rate of vesicles accumulation. OXT-specific expression of dominant-negative Cdc42, which is a key regulator of actin dynamics and a downstream effector of Robo2, led to a dose-dependent increase in OXT content in WT, and a dampened effect in robo2 mutants. Our results link Slit3-Robo2-Cdc42, which controls local actin dynamics, with the maintenance of synaptic neuropeptide levels.
Assuntos
Actinas/metabolismo , Mutação , Ocitocina/genética , Receptores Imunológicos/genética , Sinapses/metabolismo , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Animais Geneticamente Modificados , Recuperação de Fluorescência Após Fotodegradação , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Microscopia de Fluorescência por Excitação Multifotônica , Ocitocina/metabolismo , Receptores Imunológicos/metabolismo , Transdução de Sinais/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/metabolismoRESUMO
The interaction of animals with conspecifics, termed social behaviour, has a major impact on the survival of many vertebrate species. Neuropeptide hormones modulate the underlying physiology that governs social interactions, and many findings concerning the neuroendocrine mechanisms of social behaviours have been extrapolated from animal models to humans. Neurones expressing neuropeptides show similar distribution patterns within the hypothalamic nucleus, even when evolutionarily distant species are compared. During evolution, hypothalamic neuropeptides and releasing hormones have retained not only their structures, but also their biological functions, including their effects on behaviour. Here, we review the current understanding of the mechanisms of social behaviours in several classes of animals, such as worms, insects and fish, as well as laboratory, wild and domesticated mammals.
Assuntos
Hipotálamo/fisiologia , Neuropeptídeos/fisiologia , Comportamento Social , AnimaisRESUMO
Alternative splicing, a fundamental step in gene expression, is deregulated in many diseases. Splicing factors (SFs), which regulate this process, are up- or down regulated or mutated in several diseases including cancer. To date, there are no inhibitors that directly inhibit the activity of SFs. We designed decoy oligonucleotides, composed of several repeats of a RNA motif, which is recognized by a single SF. Here we show that decoy oligonucleotides targeting splicing factors RBFOX1/2, SRSF1 and PTBP1, can specifically bind to their respective SFs and inhibit their splicing and biological activities both in vitro and in vivo. These decoy oligonucleotides present an approach to specifically downregulate SF activity in conditions where SFs are either up-regulated or hyperactive.
Assuntos
Ribonucleoproteínas Nucleares Heterogêneas/genética , Oligonucleotídeos/farmacologia , Proteína de Ligação a Regiões Ricas em Polipirimidinas/genética , Fatores de Processamento de RNA/genética , Fatores de Processamento de Serina-Arginina/genética , Processamento Alternativo , Animais , Animais Geneticamente Modificados , Sítios de Ligação , Glioblastoma/genética , Glioblastoma/patologia , Células HEK293 , Ribonucleoproteínas Nucleares Heterogêneas/antagonistas & inibidores , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/genética , Músculo Esquelético/crescimento & desenvolvimento , Degradação do RNAm Mediada por Códon sem Sentido , Oligonucleotídeos/química , Oligonucleotídeos/metabolismo , Proteína de Ligação a Regiões Ricas em Polipirimidinas/antagonistas & inibidores , Proteína de Ligação a Regiões Ricas em Polipirimidinas/metabolismo , Fatores de Processamento de RNA/antagonistas & inibidores , Fatores de Processamento de RNA/metabolismo , Fatores de Processamento de Serina-Arginina/antagonistas & inibidores , Fatores de Processamento de Serina-Arginina/metabolismo , Sequências de Repetição em Tandem , Ensaios Antitumorais Modelo de Xenoenxerto , Peixe-Zebra/embriologia , Peixe-Zebra/genéticaRESUMO
The mechanism controlling the development of dopaminergic (DA) and serotonergic (5HT) neurons in vertebrates is not well understood. Here we characterized a zebrafish mutant--too few (tof)--that develops hindbrain 5HT and noradrenergic neurons, but does not develop hypothalamic DA and 5HT neurons. tof encodes a forebrain-specific zinc finger transcription repressor that is homologous to the mammalian Fezl (forebrain embryonic zinc finger-like protein). Mosaic and co-staining analyses showed that fezl was not expressed in DA or 5HT neurons and instead controlled development of these neurons non-cell-autonomously. Both the eh1-related repressor motif and the second zinc finger domain were necessary for tof function. Our results indicate that tof/fezl is a key component in regulating the development of monoaminergic neurons in the vertebrate brain.