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1.
Chemosphere ; 249: 126148, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32062212

RESUMO

Cypermethrin is one of the widely used type-II pyrethroid and the indiscriminate use of this pesticide leads to life threatening effects and in particular showed developmental effects in sensitive populations such as children and pregnant woman. However, the molecular mechanisms underlying cypermethrin-induced development toxicity is not well defined. To address this gap, the present study was designed to investigate the phenotypic and transcriptomic (next generation RNA-Seq method) impact of cypermethrin in zebrafish embryos as a model system. Zebrafish embryos at two time points, 24 h postfertilization (hpf) and 48 hpf were exposed to cypermethrin at a concentration of 10 µg/L. Respective control groups were maintained. Cypermethrin induced both phenotypic and transcriptomic changes in zebrafish embryos at 48 hpf. The phenotypic anomalies such as delayed hatching rate, increased heartbeat rate and deformed axial spinal curvature in cypermethrin exposed zebrafish embryos at 48 hpf as compared to its respective controls. Transcriptomic analysis indicated that cypermethrin exposure altered genes associated with visual/eye development and gene functional profiling also revealed that cypermethrin stress over a period of 48 h disrupts phototransduction pathway in zebrafish embryos. Interestingly, cypermethrin exposure resulted in up regulation of only one gene, tnnt3b, fast muscle troponin isoform 3T in 24 hpf embryos as compared to its respective controls. The present model system, cypermethrin exposed zebrafish embryos elaborates the toxic consequences of cypermethrin exposure during developmental stages, especially in fishes. The present findings paves a way to understand the visual impairment in sensitive populations such as children exposed to cypermethrin during their embryonic period and further research is warranted.


Assuntos
Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/embriologia , Animais , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/fisiologia , Perfilação da Expressão Gênica , Larva/efeitos dos fármacos , Praguicidas/metabolismo , Transcriptoma , Peixe-Zebra/metabolismo
2.
Nat Neurosci ; 23(3): 363-374, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32066987

RESUMO

Recent reports have revealed that oligodendrocyte precursor cells (OPCs) are heterogeneous. It remains unclear whether such heterogeneity reflects different subtypes of cells with distinct functions or instead reflects transiently acquired states of cells with the same function. By integrating lineage formation of individual OPC clones, single-cell transcriptomics, calcium imaging and neural activity manipulation, we show that OPCs in the zebrafish spinal cord can be divided into two functionally distinct groups. One subgroup forms elaborate networks of processes and exhibits a high degree of calcium signaling, but infrequently differentiates despite contact with permissive axons. Instead, these OPCs divide in an activity- and calcium-dependent manner to produce another subgroup, with higher process motility and less calcium signaling and that readily differentiates. Our data show that OPC subgroups are functionally diverse in their response to neurons and that activity regulates the proliferation of a subset of OPCs that is distinct from the cells that generate differentiated oligodendrocytes.


Assuntos
Bainha de Mielina/fisiologia , Células Precursoras de Oligodendrócitos/fisiologia , Animais , Animais Geneticamente Modificados , Sinalização do Cálcio/fisiologia , Diferenciação Celular , Divisão Celular , Linhagem da Célula , Proliferação de Células , Embrião não Mamífero/fisiologia , Rede Nervosa/citologia , Rede Nervosa/fisiologia , Medula Espinal/citologia , Medula Espinal/fisiologia , Natação/fisiologia , Peixe-Zebra
3.
Proc Natl Acad Sci U S A ; 117(6): 3254-3260, 2020 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-32001507

RESUMO

The giant Mauthner (M) cell is the largest neuron known in the vertebrate brain. It has enabled major breakthroughs in neuroscience but its ultimate function remains surprisingly unclear: An actual survival value of M cell-mediated escapes has never been supported experimentally and ablating the cell repeatedly failed to eliminate all rapid escapes, suggesting that escapes can equally well be driven by smaller neurons. Here we applied techniques to simultaneously measure escape performance and the state of the giant M axon over an extended period following ablation of its soma. We discovered that the axon survives remarkably long and remains still fully capable of driving rapid escape behavior. By unilaterally removing one of the two M axons and comparing escapes in the same individual that could or could not recruit an M axon, we show that the giant M axon is essential for rapid escapes and that its loss means that rapid escapes are also lost forever. This allowed us to directly test the survival value of the M cell-mediated escapes and to show that the absence of this giant neuron directly affects survival in encounters with a natural predator. These findings not only offer a surprising solution to an old puzzle but demonstrate that even complex brains can trust vital functions to individual neurons. Our findings suggest that mechanisms must have evolved in parallel with the unique significance of these neurons to keep their axons alive and connected.


Assuntos
Reação de Fuga/fisiologia , Sistema Nervoso/crescimento & desenvolvimento , Neurônios/citologia , Neurônios/fisiologia , Animais , Axônios/fisiologia , Embrião não Mamífero/fisiologia , Larva/fisiologia , Peixe-Zebra
4.
Chemosphere ; 247: 125870, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31931321

RESUMO

As a new protective and therapeutic fungicide, studies on famoxadone-cymoxanil are rare, and its toxicity to aquatic organisms has not been reported. In the present study, zabrafish embryos were exposed to several concentrations of famoxadone-cymoxanil at 10 hpf. Then, the changes of their shape, heart rate, development and function of innate and adaptive immune cells, oxidative stress, apoptosis, the expression of apoptosis-related genes and immune-related genes, the locomotor behavior were observed and detected in acute toxicity of famoxadone-cymoxanil. Our studies showed that, after exposure to famoxadone-cymoxanil, zebrafish embryos had decreased heart rate, shortened body length, swollen yolk sac. Secondly, the number of innate and adaptive immune cells was significantly reduced; and neutrophil migration and retention at the injury area were inhibited, indicating the developmental toxicity and immunotoxicity of famoxadone-cymoxanil on the zebrafish. We also found that the oxidative stress related indicators of embryos were changed significantly, and apoptosis were substantially increased. Further investigation of changes of some key genes in TLR signaling including TLR4, MYD88 and NF-κB p65 revealed that the mRNA expression of these genes was up-regulated. Meanwhile, the mRNA expression of some proinflammatory cytokines such as TNF-α, IFN-γ, IL6 and IL-1ß was also up-regulated. In addition, the activity, the total distance, time and average speed were decreased along with the increase of exposure concentration. The absolute turn angle, sinuosity and the enzymatic activity of acetylcholinesterase (AChE) were also increased. These results suggested that famoxadone-cymoxanil can induce developmental toxicity, immunotoxicity and neurobehavioral toxicity in zebrafish larvae.


Assuntos
Acetamidas/toxicidade , Comportamento Animal/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Estrobilurinas/toxicidade , Linfócitos T/efeitos dos fármacos , Peixe-Zebra , Animais , Apoptose/efeitos dos fármacos , Embrião não Mamífero/imunologia , Embrião não Mamífero/fisiologia , Desenvolvimento Embrionário/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Linfócitos T/patologia , Receptor 4 Toll-Like/genética , Peixe-Zebra/genética
5.
Proc Natl Acad Sci U S A ; 117(4): 1853-1859, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31932426

RESUMO

Living systems are more robust, diverse, complex, and supportive of human life than any technology yet created. However, our ability to create novel lifeforms is currently limited to varying existing organisms or bioengineering organoids in vitro. Here we show a scalable pipeline for creating functional novel lifeforms: AI methods automatically design diverse candidate lifeforms in silico to perform some desired function, and transferable designs are then created using a cell-based construction toolkit to realize living systems with the predicted behaviors. Although some steps in this pipeline still require manual intervention, complete automation in future would pave the way to designing and deploying unique, bespoke living systems for a wide range of functions.


Assuntos
Algoritmos , Automação , Bioengenharia/métodos , Simulação por Computador , Embrião não Mamífero/fisiologia , Modelos Biológicos , Xenopus laevis/fisiologia , Animais , Células Artificiais , Embrião não Mamífero/citologia , Humanos
6.
Science ; 367(6476): 453-458, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31974255

RESUMO

Tissue morphogenesis is driven by local cellular deformations that are powered by contractile actomyosin networks. How localized forces are transmitted across tissues to shape them at a mesoscopic scale is still unclear. Analyzing gastrulation in entire avian embryos, we show that it is driven by the graded contraction of a large-scale supracellular actomyosin ring at the margin between the embryonic and extraembryonic territories. The propagation of these forces is enabled by a fluid-like response of the epithelial embryonic disk, which depends on cell division. A simple model of fluid motion entrained by a tensile ring quantitatively captures the vortex-like "polonaise" movements that accompany the formation of the primitive streak. The geometry of the early embryo thus arises from the transmission of active forces generated along its boundary.


Assuntos
Actomiosina/fisiologia , Embrião não Mamífero/fisiologia , Gastrulação/fisiologia , Actomiosina/química , Âmnio , Animais , Anisotropia , Divisão Celular , Codorniz/embriologia , Resistência à Tração
7.
Environ Pollut ; 256: 113437, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31672357

RESUMO

Pesticides often occur as mixtures of complex compounds in water environments, while most of studies only focus on the toxic effects of individual pesticides with little attention to the joint toxic effects. In the present study, we aimed to the mixture toxicity of beta-cypermethrin (BCY) and thiacloprid (THI) to zebrafish (Danio rerio) employing multiple toxicological endpoints. Results displayed that the 96-h LC50 values of BCY to D. rerio at various developmental stages ranged from 2.64 × 10 (1.97 × 10-3.37 × 10) to 6.03 × 103 (4.54 × 103-1.05 × 104) nM, which were lower than those of THI ranging from 2.97 × 104 (1.96 × 104-4.25 × 104) to 2.86 × 105 (2.19 × 105-5.87 × 105) nM. Mixtures of BCY and THI exhibited synergistic response in embryonic zebrafish. Meanwhile, the enzyme activities of antioxidants (CAT and SOD) and detoxification enzyme (CarE), endogenous T-GSH and MDA contents, as well as gene expressions (tsh, crh, cxcl and bax) involved in oxidative stress, cellular apoptosis, immune system and endocrine system were obviously changed in the mixture exposure compared with the respective BCY or THI treatment. Consequently, the increased toxicity of pesticide mixture suggested that the toxicological data acquired from individual pesticide tests might underrate the toxicity risk of pesticides that actually arise in the real environment. Taken together, our present study provided evidence that mixture exposure of BCY and THI could induce additional toxic effect compared with their respective individual pesticides on D. rerio, offering valuable insights into the toxic mechanism of pesticide mixture.


Assuntos
Neonicotinoides/toxicidade , Praguicidas/toxicidade , Piretrinas/toxicidade , Tiazinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Embrião não Mamífero/metabolismo , Embrião não Mamífero/fisiologia , Expressão Gênica/efeitos dos fármacos , Larva/metabolismo , Estresse Oxidativo , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo
8.
Chemosphere ; 242: 125143, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31675585

RESUMO

Ochratoxin A (OTA), a mycotoxin widely found in foodstuffs, reportedly damages multiple brain regions in developing rodents, but the corresponding mechanisms have not been elucidated. In this study, zebrafish embryos at 6 h post fertilization (hpf) were exposed to various concentrations of OTA and the phenomenon associated with intracerebral hemorrhage was observed at 72 hpf. Exposure of embryos to OTA significantly increased their hemorrhagic rate in a dose-dependent manner. Large numbers of extravagated erythrocytes were observed in the midbrain/hindbrain areas of Tg(fli-1a:EGFP; gata1:DsRed) embryos following exposure to OTA. OTA also disrupted the vascular patterning, especially the arch-shaped central arteries (CtAs), in treated embryos. Histological analysis revealed a cavity-like pattern in their hindbrain ventricles, implying the possibility of cerebral edema. OTA-induced intracerebral hemorrhage and CtA vessel defects were partially reversed by the presence of miR-731 antagomir or the overexpression of prolactin receptor a (prlra); prlra is a downstream target of miR-731. These results suggest that exposure to OTA has a negative effect on cerebral vasculature development by interfering with the miR-731/PRLR axis in zebrafish.


Assuntos
Hemorragia Cerebral/induzido quimicamente , Ocratoxinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/fisiologia , Eritrócitos/efeitos dos fármacos , MicroRNAs , Micotoxinas , Receptores da Prolactina/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/fisiologia
9.
Sci Total Environ ; 702: 134703, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31733549

RESUMO

Cardiovascular agents are among the most frequently prescribed pharmaceuticals worldwide. They are widely detected in aquatic ecosystems, while their ecotoxicological implications are rarely explored. Here, by the use of a new developed high-throughput zebrafish embryo screening approach, we systematically assessed the cardiovascular disruptive effects of 32 commonly used cardiovascular agents at environmental relevant concentrations and above (0.04, 0.2 and 1 µM). Multiple endpoints, including cardiac output, heart rate and blood flow, were quantified via customized video analysis approaches. Among the 32 agents, simvastatin and lovastatin exhibited the strongest toxicities to fish embryos, and the lethal doses were observed at 0.2 µM and 1 µM. Beta-blockers such as atenolol and metoprolol significantly decreased heart rates by up to 15% and 12% and increased blood flows by up to 14% and 14%, respectively, at concentrations as low as 0.04 µM. Several hypertension/hyperlipidemia medications such as pravastatin and enalapril led to significant inhibition of heart rates (up to 14% and 16% decreases, respectively) as well as slightly decreases of the cardiac outputs and blood flows. In addition, a tentative risk assessment clearly demonstrated that some compounds such as atenolol, metoprolol and bezafibrate pose considerable risks to aquatic organisms at environmental or slightly higher than surface water concentrations. Our results provided novel insights into understanding of the potential risks of cardiovascular agents and contributed to their environmental hazard ranking.


Assuntos
Fármacos Cardiovasculares/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/embriologia , Animais , Atenolol , Ecotoxicologia , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/fisiologia , Metoprolol , Medição de Risco
10.
Ecotoxicol Environ Saf ; 190: 110071, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31841896

RESUMO

Aquatic environments are affected by the use of pesticides in agricultural areas near rivers. To assess the impact of pesticide residues on affected environments Danio rerio (zebrafish) embryos have become an alternative model for biomonitoring studies. In the present study, zebrafish embryos were used as bioindicator of water quality in the Vacacaí river, located in the city of Santa Maria, southern Brazil. We hypothesized that it would be possible to observe changes in the biomarkers tested in the embryos. Exposures were performed over a total of eight months during the year 2018 using water collected in a river located near agricultural areas. Twenty-four pesticides were found in river water samples. The most frequently found were atrazine, quinclorac and clomazone. During exposure (96 h) spontaneous movement, the heart rate and hatching rate were evaluated. After the exposure time the embryos were euthanized for biochemical assays. We analyzed biomarkers such as thiobarbituric acid reactive substance (TBARS), acetylcholinesterase (AChE), glutathione S-transferase (GST) and catalase (CAT). We observed increases in GST and TBARS, especially during periods of major water contamination such as January, February, October, and November. Pesticides can affect the development of native species that reproduce during periods of high agricultural production. These results demonstrate the potential use of biochemical parameters combined with developmental and behavioral analyses in zebrafish embryos for biomonitoring studies.


Assuntos
Praguicidas/análise , Rios/química , Poluentes Químicos da Água/análise , Acetilcolinesterase/metabolismo , Agricultura , Animais , Biomarcadores/metabolismo , Brasil , Catalase/metabolismo , Embrião não Mamífero/fisiologia , Glutationa Transferase/metabolismo , Frequência Cardíaca , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/fisiologia
11.
Chemosphere ; 245: 125632, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31864044

RESUMO

Mechanistic information is essential to screen and predict the adverse effects of a large number of chemicals during early-life exposure. Concentration-dependent omics can capture the extent of perturbations of biological pathways or processes and provide information on the mechanism of toxicity. However, the application of concentration-dependent transcriptome to assess the developmental toxicity of environmental chemicals is still limited. Here, twelve chemicals representing five different modes of action (MOAs) were tested by the concentration-dependent reduced zebrafish transcriptome approach (CRZT) in combination with a phenotype-based high content screen (PHCS). The responsiveness, sensitivity and mechanistic differentiation of CRZT were validated in comparison with PHCS. First, PHCS identified 10 chemicals with obvious embryotoxicity (LD50 range: 2.11-70.68 µM), while the potencies of the biological pathways perturbed by 12 chemicals (PODpath20 range: 0.002-2.1 µM) were demonstrated by CRZT. Second, although the potency of the transcriptome perturbations was positively correlated with lethality (LD50) (R2 = 0.64, P-value < 0.05) for most tested chemicals, BbF was non-embryotoxic but was the most potent on the perturbance of biological pathways. Finally, the profiles of the perturbed biological processes and the transcriptome potency (PODpath20) captured by CRZT could effectively classify most chemicals corresponding to their known MOAs. In summary, CRZT could significantly improve testing the developmental toxicity of environmental chemicals.


Assuntos
Embrião não Mamífero/fisiologia , Monitoramento Ambiental/métodos , Transcriptoma/fisiologia , Peixe-Zebra/embriologia , Animais , Embrião não Mamífero/efeitos dos fármacos , Peixe-Zebra/metabolismo
12.
Proc Natl Acad Sci U S A ; 117(2): 836-847, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31882445

RESUMO

Predicting how interactions between transcription factors and regulatory DNA sequence dictate rates of transcription and, ultimately, drive developmental outcomes remains an open challenge in physical biology. Using stripe 2 of the even-skipped gene in Drosophila embryos as a case study, we dissect the regulatory forces underpinning a key step along the developmental decision-making cascade: the generation of cytoplasmic mRNA patterns via the control of transcription in individual cells. Using live imaging and computational approaches, we found that the transcriptional burst frequency is modulated across the stripe to control the mRNA production rate. However, we discovered that bursting alone cannot quantitatively recapitulate the formation of the stripe and that control of the window of time over which each nucleus transcribes even-skipped plays a critical role in stripe formation. Theoretical modeling revealed that these regulatory strategies (bursting and the time window) respond in different ways to input transcription factor concentrations, suggesting that the stripe is shaped by the interplay of 2 distinct underlying molecular processes.


Assuntos
Drosophila/fisiologia , Embrião não Mamífero/fisiologia , Desenvolvimento Embrionário/fisiologia , Fatores de Transcrição/metabolismo , Animais , Núcleo Celular , Drosophila/embriologia , Drosophila/genética , Proteínas de Drosophila , Desenvolvimento Embrionário/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genes de Insetos , Masculino , Modelos Biológicos , RNA Mensageiro , Transcrição Genética
13.
Environ Pollut ; 255(Pt 2): 113269, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31574395

RESUMO

Triazole fungicides are widely used in agriculture production and have adverse impacts on aquatic organisms. As one of the triazole fungicides, prothioconazole has been reported to cause many toxicological effects, but its risks to aquatic organisms are unknown. In this study, we systematically explored the toxicity effects of prothioconazole exposure on zebrafish embryos (Danio rerio) involving in developmental toxicity, oxidative damage and metabolism disorders. The results showed that prothioconazole exposure to zebrafish embryos produced a series of toxic symptoms, including hatching inhibition, shortening of body length, pericardial cyst and yolk cyst. In addition, prothioconazole exposure caused significant lipid peroxidation and oxidative damage. Particularly, we also found that metabolites and genes involved in lipid metabolism also showed significant changes. This study may provide theoretical basis for systematically assessing the potential risks of zebrafish embryos with prothioconazole exposure.


Assuntos
Embrião não Mamífero/fisiologia , Fungicidas Industriais/toxicidade , Triazóis/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/fisiologia , Animais , Organismos Aquáticos , Embrião não Mamífero/efeitos dos fármacos , Metabolismo dos Lipídeos , Peroxidação de Lipídeos , Poluentes Químicos da Água/análise , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo
14.
Nat Commun ; 10(1): 4796, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31641138

RESUMO

Interneurons (INs) coordinate motoneuron activity to generate appropriate patterns of muscle contractions, providing animals with the ability to adjust their body posture and to move over a range of speeds. In Drosophila larvae several IN subtypes have been morphologically described and their function well documented. However, the general lack of molecular characterization of those INs prevents the identification of evolutionary counterparts in other animals, limiting our understanding of the principles underlying neuronal circuit organization and function. Here we characterize a restricted subset of neurons in the nerve cord expressing the Maf transcription factor Traffic Jam (TJ). We found that TJ+ neurons are highly diverse and selective activation of these different subtypes disrupts larval body posture and induces specific locomotor behaviors. Finally, we show that a small subset of TJ+ GABAergic INs, singled out by the expression of a unique transcription factors code, controls larval crawling speed.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila/fisiologia , Interneurônios/fisiologia , Fatores de Transcrição Maf Maior/metabolismo , Atividade Motora/fisiologia , Proteínas Proto-Oncogênicas/metabolismo , Animais , Animais Geneticamente Modificados , Drosophila/embriologia , Proteínas de Drosophila/genética , Embrião não Mamífero/fisiologia , Regulação da Expressão Gênica , Inativação Gênica , Larva/fisiologia , Locomoção/fisiologia , Fatores de Transcrição Maf Maior/genética , Proteínas Proto-Oncogênicas/genética , Raízes Nervosas Espinhais/fisiologia , Ácido gama-Aminobutírico/metabolismo
15.
Zygote ; 27(5): 329-336, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31412969

RESUMO

Mammalian Pou5f1 encodes the POU family class V (POU-V) transcription factor which is essential for the pluripotency of embryonic cells and germ cells. In vertebrates, various POU-V family genes have been identified and classified into the POU5F1 family or its paralogous POU5F3 family. In this study, we cloned two cDNAs named CpPou5f1 and CpPou5f3, which encode POU-V family proteins of the Japanese red bellied newt Cynops pyrrhogaster. In the predicted amino acid sequence encoded by CpPou5f1, the typical MAGH sequence at the N-terminus and deletion of arginine at the fifth position of POU-homeodomain were recognized, but not in the sequence encoded by CpPou5f3. Phylogenetic analysis using Clustal Omega software indicated that CpPou5f1 and CpPou5f3 are classified into the clade of the POU5F1 and POU5F3 families, respectively. In a real-time polymerase chain reaction (RT-PCR) analysis, the marked gene expression of CpPou5f1 was observed during oogenesis and early development up to the tail-bud stage, whereas weak gene expression of CpPou5f3 was detected only in the early stages of oogenesis and gastrula. In adult organs, CpPou5f1 was expressed only in the ovary, while gene expression of CpPou5f3 was recognized in various organs. A regeneration experiment using larval forelimb revealed that transient gene expression of CpPou5f1 occurred at the time of wound healing, followed by gene activation of CpPou5f3 during the period of blastema formation. These results suggest that CpPou5f1 and CpPou5f3 might play different roles in embryogenesis and limb regeneration.


Assuntos
Oogênese/genética , Fatores do Domínio POU/genética , Regeneração/genética , Salamandridae/genética , Animais , Embrião não Mamífero/fisiologia , Extremidades/fisiologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Masculino , Família Multigênica , Filogenia , Salamandridae/embriologia , Salamandridae/fisiologia
16.
Environ Pollut ; 254(Pt A): 113027, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31421573

RESUMO

3,3'-dichlorobiphenyl (PCB-11) is an emerging PCB congener widely detected in environmental samples and human serum, but its toxicity potential is poorly understood. We assessed the effects of three concentrations of PCB-11 on embryotoxicity and Aryl hydrocarbon receptor (Ahr) pathway interactions in zebrafish embryos (Danio rerio). Wildtype AB or transgenic Tg(gut:GFP) strain zebrafish embryos were exposed to static concentrations of PCB-11 (0, 0.2, 2, or 20 µM) from 24 to 96 h post fertilization (hpf), and gross morphology, Cytochrome P4501a (Cyp1a) activity, and liver development were assessed via microscopy. Ahr interactions were probed via co-exposures with PCB-126 or beta-naphthoflavone (BNF). Embryos exposed to 20 µM PCB-11 were also collected for PCB-11 body burden, qRT-PCR, RNAseq, and histology. Zebrafish exposed to 20 µM PCB-11 absorbed 0.18% PCB-11 per embryo at 28 hpf and 0.61% by 96 hpf, and their media retained 1.36% PCB-11 at 28 hpf and 0.84% at 96 hpf. This concentration did not affect gross morphology, but altered the transcription of xenobiotic metabolism and liver development genes, impeded liver development, and increased hepatocyte vacuole formation. In co-exposures, 20 µM PCB-11 prevented deformities caused by PCB-126 but exacerbated deformities in co-exposures with BNF. This study suggests that PCB-11 can affect liver development, act as a partial agonist/antagonist of the Ahr pathway, and act as an antagonist of Cyp1a activity to modify the toxicity of compounds that interact with the Ahr pathway.


Assuntos
Citocromo P-450 CYP1A1/metabolismo , Embrião não Mamífero/efeitos dos fármacos , Bifenilos Policlorados/toxicidade , Receptores de Hidrocarboneto Arílico/metabolismo , Poluentes Químicos da Água/toxicidade , Proteínas de Peixe-Zebra/metabolismo , Animais , Animais Geneticamente Modificados , Embrião não Mamífero/fisiologia , Ligantes , Testes de Toxicidade , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética
17.
Sci Total Environ ; 689: 1201-1211, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31358486

RESUMO

Senescence is an irreversible process that is a characteristic of age-associated disease like Type 2 diabetes (T2D). Bisphenol-A (BPA), one of the most common endocrine disruptor chemicals, received special attention in the development of insulin resistance and T2D. To understand the role played by BPA in cellular senescence under metabolic stress, zebrafish embryos were exposed to BPA in the absence and presence of hyperglycaemia. Transcriptional levels of the senescence markers p15, p53, Rb1 and ß-galactosidase were increased when BPA was combined with metabolic stress. In addition, zebrafish embryos that were exposed to combination of hyperglycaemia and BPA exhibited increased levels of apoptosis. However, cellular senescence remained induced by a combination of hyperglycaemia and BPA exposure even in the absence of a translated p53 protein suggesting that senescence is primarily independent of it but dependent on the p15-Rb1 pathway under our experimental conditions. To confirm that our results hold true in adult mammalian tissues, we validated our embryonic experiments in an adult mammalian metabolic model of skeletal muscle cells. Our work reveals a novel and unique converging role of senescence and apoptosis axis contributing to glucose dyshomeostasis. Thus, we conclude that BPA exposure can exacerbate existing metabolic stress to increase cellular senescence that leads to aggravation of disease phenotype in age-associated diseases like type 2 diabetes.


Assuntos
Compostos Benzidrílicos/toxicidade , Senescência Celular/genética , Disruptores Endócrinos/toxicidade , Fenóis/toxicidade , Proteína Supressora de Tumor p53/genética , Poluentes Químicos da Água/toxicidade , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/fisiologia , Animais , Embrião não Mamífero/fisiologia , Estresse Fisiológico , Proteína Supressora de Tumor p53/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
18.
PLoS One ; 14(7): e0219368, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31291310

RESUMO

Temperature extremes alter development, growth, hatching, and survival of eggs of ground-nesting birds, particularly during pre-incubation (egg laying) when eggs are left unattended and exposed to the environment for days or weeks before parental incubation begins. The northern bobwhite quail is a ground-nesting bird whose eggs experience high temperatures (≥45° C) during pre-incubation. It is known that chronic high temperatures during pre-incubation alter development and reduce hatching and survival of bobwhite eggs, but it is not known if acute doses of high temperatures during pre-incubation have the same effect. In this study, the 12-d pre-incubation period was divided into thirds. Fresh bobwhite eggs were exposed to either a commercial holding temperature for all 12 d (serving as a control), or a high oscillating temperature regimen for 4 d (one third of pre-incubation) either in the early, middle, or late third of pre-incubation, with a low oscillating temperature regimen during the remaining 8 d. The timing of acute exposure to high oscillating temperatures significantly affected bobwhite development. Eggs exposed in the first 2/3 of pre-incubation developed twice as much as eggs exposed late in pre-incubation, even though all eggs received the same amount of heating degree-hours. Thus, a critical window of thermal susceptibility exists for developing northern bobwhites. Acute exposure to high oscillating temperatures resulted in reduced hatchling mass, hatching success, survival, and compromised hatching synchrony. Thus, acute hyperthermic nest temperatures during pre-incubation could result in the observed reductions in the percentage of juveniles in natural populations during hot and droughty years.


Assuntos
Colinus/crescimento & desenvolvimento , Desenvolvimento Embrionário/fisiologia , Oviposição/fisiologia , Animais , Embrião não Mamífero/fisiologia , Feminino , Temperatura Alta , Gravidez , Reprodução/fisiologia
19.
Dev Cell ; 49(6): 829-839.e5, 2019 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-31178400

RESUMO

Embryonic organizers establish gradients of diffusible signaling molecules to pattern the surrounding cells. Here, we elucidate an additional mechanism of embryonic organizers that is a secondary consequence of morphogen signaling. Using pharmacological and localized transgenic perturbations, 4D imaging of the zebrafish embryo, systematic analysis of cell motion, and computational modeling, we find that the vertebrate tail organizer orchestrates morphogenesis over distances beyond the range of morphogen signaling. The organizer regulates the rate and coherence of cell motion in the elongating embryo using mechanical information that is transmitted via relay between neighboring cells. This mechanism is similar to a pressure front in granular media and other jammed systems, but in the embryo the mechanical information emerges from self-propelled cell movement and not force transfer between cells. The propagation likely relies upon local biochemical signaling that affects cell contractility, cell adhesion, and/or cell polarity but is independent of transcription and translation.


Assuntos
Movimento Celular , Embrião não Mamífero/fisiologia , Desenvolvimento Embrionário , Organizadores Embrionários/crescimento & desenvolvimento , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/embriologia , Animais , Padronização Corporal , Embrião não Mamífero/citologia , Fenômenos Mecânicos , Organizadores Embrionários/metabolismo , Transdução de Sinais
20.
PLoS One ; 14(6): e0218286, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31188878

RESUMO

The transcription factor 12 (tcf12) is a basic Helix-Loop-Helix protein (bHLH) of the E-protein family, proven to play an important role in developmental processes like neurogenesis, mesoderm formation, and cranial vault development. In humans, mutations in TCF12 lead to craniosynostosis, a congenital birth disorder characterized by the premature fusion of one or several of the cranial sutures. Current research has been primarily focused on functional studies of TCF12, hence the cellular expression profile of this gene during embryonic development and early stages of ossification remains poorly understood. Here we present the establishment and detailed analysis of two transgenic tcf12:EGFP fluorescent zebrafish (Danio rerio) reporter lines. Using these transgenic lines, we analyzed the general spatiotemporal expression pattern of tcf12 during different developmental stages and put emphasis on skeletal development and cranial suture patterning. We identified robust tcf12 promoter-driven EGFP expression in the central nervous system (CNS), the heart, the pronephros, and the somites of zebrafish embryos. Additionally, expression was observed inside the muscles and bones of the viscerocranium in juvenile and adult fish. During cranial vault development, the transgenic fish show a high amount of tcf12 expressing cells at the growth fronts of the ossifying frontal and parietal bones and inside the emerging cranial sutures. Subsequently, we tested the transcriptional activity of three evolutionary conserved non-coding elements (CNEs) located in the tcf12 locus by transient transgenic assays and compared their in vivo activity to the expression pattern determined in the transgenic tcf12:EGFP lines. We could validate two of them as tcf12 enhancer elements driving specific gene expression in the CNS during embryogenesis. Our newly established transgenic lines enhance the understanding of tcf12 gene regulation and open up the possibilities for further functional investigation of these novel tcf12 enhancer elements in zebrafish.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Embrião não Mamífero/fisiologia , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/genética , Animais , Animais Geneticamente Modificados/genética , Suturas Cranianas/crescimento & desenvolvimento , Craniossinostoses/genética , Osteogênese/fisiologia , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/genética
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