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1.
Acta Vet Scand ; 61(1): 47, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31601238

RESUMO

BACKGROUND: Among the most prominent health problems marring the global poultry industry for several decades are skeletal abnormalities. The aim of this study was to investigate a recent emergence of a novel form of skeletal deformity affecting cervical spine in broiler chickens. This work presents the natural history of this newly emerging skeletal anomaly along with long term observations of epidemiological trends in commercial broiler flocks, and clinical and pathological features. RESULTS: In distinction from other forms of skeletal deformities commonly reported in broiler chickens, this new form of cervical spine anomaly have been observed in newly hatched chicks and in fully developed embryos that died in the shell. On clinical and post mortem examination this condition presents characteristic features consistent with congenital cervical scoliosis and torticollis (CCST). The pathogenesis of CCST appears to be linked to pathological remodeling of the cervical vertebrae bone associated with excessive activity of osteoclasts. Long term observations indicate that the incidence of CCST showed increasing epidemiological trends over time. More recently CCST has been observed in newly hatched chicks with incidence ranging from 0.1 to > 1%, and in fully developed embryos that failed to hatch about 4 to 5%. CONCLUSIONS: The increasing trends in incidence of CCST in commercial broiler flocks are of concern from an economic perspective, and also represent a very specific and important aspect of animal welfare.


Assuntos
Vértebras Cervicais/anormalidades , Galinhas/anormalidades , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/patologia , Escoliose/veterinária , Torcicolo/congênito , Criação de Animais Domésticos , Animais , Embrião não Mamífero , Osteoclastos/patologia , Escoliose/epidemiologia , Escoliose/patologia , Torcicolo/epidemiologia , Torcicolo/patologia , Torcicolo/veterinária
2.
Results Probl Cell Differ ; 68: 127-154, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31598855

RESUMO

Cells are arranged into species-specific patterns during early embryogenesis. Such cell division patterns are important since they often reflect the distribution of localized cortical factors from eggs/fertilized eggs to specific cells as well as the emergence of organismal form. However, it has proven difficult to reveal the mechanisms that underlie the emergence of cell positioning patterns that underlie embryonic shape, likely because a systems-level approach is required that integrates cell biological, genetic, developmental, and mechanical parameters. The choice of organism to address such questions is also important. Because ascidians display the most extreme form of invariant cleavage pattern among the metazoans, we have been analyzing the cell biological mechanisms that underpin three aspects of cell division (unequal cell division (UCD), oriented cell division (OCD), and asynchronous cell cycles) which affect the overall shape of the blastula-stage ascidian embryo composed of 64 cells. In ascidians, UCD creates two small cells at the 16-cell stage that in turn undergo two further successive rounds of UCD. Starting at the 16-cell stage, the cell cycle becomes asynchronous, whereby the vegetal half divides before the animal half, thus creating 24-, 32-, 44-, and then 64-cell stages. Perturbing either UCD or the alternate cell division rhythm perturbs cell position. We propose that dynamic cell shape changes propagate throughout the embryo via cell-cell contacts to create the ascidian-specific invariant cleavage pattern.


Assuntos
Padronização Corporal , Divisão Celular , Embrião não Mamífero/citologia , Embrião não Mamífero/embriologia , Urocordados/citologia , Urocordados/embriologia , Animais , Fertilização
3.
Results Probl Cell Differ ; 68: 379-418, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31598865

RESUMO

The developmental adaptations of the marsupial frogs Gastrotheca riobambae and Flectonotus pygmaeus (Hemiphractidae) are described and compared with frogs belonging to seven additional families. Incubation of embryos by the mother in marsupial frogs is associated with changes in the anatomy and physiology of the female, modifications of oogenesis, and extraordinary changes in embryonic development. The comparison of early development reveals that gene expression is highly conserved. However, the timing of gene expression varies between frog species. There are two modes of gastrulation according to the onset of convergent extension. In gastrulation mode 1, convergent extension is an intrinsic mechanism of gastrulation. This gastrulation mode occurs in frogs with aquatic reproduction, such as Xenopus laevis. In gastrulation mode 2, convergent extension occurs after the completion of gastrulation movements. Gastrulation mode 2 occurs in frogs with terrestrial reproduction, such as the marsupial frog, G. riobambae. The two modes of frog gastrulation resemble the two transitions toward meroblastic cleavage of ray-finned fishes (Actinopterygii). The comparison indicates that a major event in the evolution of frog terrestrial development is the separation of convergent extension from gastrulation.


Assuntos
Anuros/embriologia , Embrião não Mamífero/embriologia , Desenvolvimento Embrionário , Animais , Gástrula/embriologia , Xenopus laevis/embriologia
4.
Chemosphere ; 235: 1022-1029, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561291

RESUMO

Chemical exposure during the early life stages of development may have long lasting effects on organisms that are rarely studied. The present work intended to evaluate the effect of embryonic exposure to the pesticide carbaryl on adult fish behavior. Zebrafish (Danio rerio) embryos were exposed, for 4 days, to sublethal concentrations of carbaryl (0.01, 0.1 and 1.0 mg/L) plus a control and then kept in standard cultivation conditions until adulthood. A battery of behavioral tests was then performed to assess anxiety-like behavior (locomotor activity, thigmotaxis and novel tank diving test), social behavior, and feeding. Developmental exposure of zebrafish to sublethal concentrations of carbaryl produced important behavioral alterations in the adulthood. Main effects included decreased locomotion/hypoactivity (increase in slow movements and decrease of medium and rapid movements), especially in the light periods. Moreover, spatial pattern also changed: while during dark periods control fish increased activity in the outer zone of the tank, this was not observed in exposed fish. Overall, this demonstrated the importance of life stage exposure, clearly demonstrating long lasting effects of a (chemical) stress event at embryonic stages. This data supports the need of considering this scenario in environmental risk evaluations. Further work should focus on the mechanistic effects of developmental disruption responsible for the effects observed.


Assuntos
Comportamento Animal/efeitos dos fármacos , Carbaril/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Inseticidas/toxicidade , Peixe-Zebra/embriologia , Animais , Locomoção/efeitos dos fármacos
5.
J Environ Sci (China) ; 85: 1-8, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31471016

RESUMO

Metalaxyl is an anilide pesticide that is widely used to control plant diseases caused by Peronosporales species. In order to study the toxic effects, zebrafish embryos were exposed to metalaxyl at nominal concentrations of 5, 50 and 500 ng/L for 72 hr, and the cardiac development and functioning of larvae were observed. The results showed that metalaxyl exposure resulted in increased rates of pericardial edema, heart hemorrhage and cardiac malformation. The distance between the sinus venosus and bulbus arteriosus, stroke volume, cardiac output and heart rate were significantly increased in larvae exposed to 50 and 500 ng/L metalaxyl compared to solvent control larvae. Significant upregulation in the transcription of tbx5, gata4 and myh6 was observed in the 50 and 500 ng/L treatments, and that of nkx2.5 and myl7 was observed in the 5, 50 and 500 ng/L groups. These disturbances may be related to cardiac developmental and functional defects in the larvae. The activity of Na+/K+-ATPase and Ca2+-ATPase was significantly increased in zebrafish embryos exposed to 500 ng/L metalaxyl, and the mRNA levels of genes related to ATPase (atp2a11, atp1b2b, and atp1a3b) (in the 50 and 500 ng/L groups) and calcium channels (cacna1ab) (in the 500 ng/L group) were significantly downregulated; these changes might be associated with heart arrhythmia and functional failure.


Assuntos
Alanina/análogos & derivados , Coração/crescimento & desenvolvimento , Poluentes Químicos da Água/toxicidade , Alanina/toxicidade , Animais , Embrião não Mamífero , Coração/efeitos dos fármacos , Peixe-Zebra/embriologia
6.
Nat Methods ; 16(8): 750-756, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31363221

RESUMO

The Drosophila wing disc has been a fundamental model system for the discovery of key signaling pathways and for our understanding of developmental processes. However, a complete map of gene expression in this tissue is lacking. To obtain a gene expression atlas in the wing disc, we employed single cell RNA sequencing (scRNA-seq) and developed a method for analyzing scRNA-seq data based on gene expression correlations rather than cell mapping. This enables us to compute expression maps for all detected genes in the wing disc and to discover 824 genes with spatially restricted expression patterns. This approach identifies clusters of genes with similar expression patterns and functional relevance. As proof of concept, we characterize the previously unstudied gene CG5151 and show that it regulates Wnt signaling. Our method will enable the leveraging of scRNA-seq data for generating expression atlases of undifferentiated tissues during development.


Assuntos
Proteínas de Drosophila/genética , Drosophila/genética , Embrião não Mamífero/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Célula Única/métodos , Asas de Animais/metabolismo , Algoritmos , Animais , Drosophila/embriologia , Embrião não Mamífero/citologia , Feminino , Perfilação da Expressão Gênica , Análise de Sequência de RNA , Asas de Animais/embriologia
7.
Aquat Toxicol ; 215: 105272, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31442592

RESUMO

A number of chemicals have been shown to affect epigenetic patterning and functions. Since epigenetic mechanisms regulate transcriptional networks, epigenetic changes induced by chemical exposure can represent early molecular events for long-term adverse physiological effects. Epigenetics has thus appeared as a research field of major interest within (eco)toxicological sciences. The present study aimed at measuring effects on epigenetic-related mechanisms of selected environmental chemicals (bisphenols, perfluorinated chemicals, methoxychlor, permethrin, vinclozolin and coumarin 47) in zebrafish embryos and liver cells (ZFL). Transcription of genes related to DNA methylation and histone modifications was measured and global DNA methylation was assessed in ZFL cells using the LUMA assay. The differences in results gathered from both models suggest that chemicals affect different mechanisms related to epigenetics in embryos and cells. In zebrafish embryos, exposure to bisphenol A, coumarin 47, methoxychlor and permethrin lead to significant transcriptional changes in epigenetic factors suggesting that they can impact early epigenome reprogramming related to embryonic development. In ZFL cells, significant transcriptional changes were observed upon exposure to all chemicals but coumarin 47; however, only perfluorooctane sulfonate induced significant effects on global DNA methylation. Notably, in contrast to the other tested chemicals, perfluorooctane sulfonate affected only the expression of the histone demethylase kdm5ba. In addition, kdm5ba appeared as a sensitive gene in zebrafish embryos as well. Taken together, the present results suggest a role for kdm5ba in regulating epigenetic patterns in response to chemical exposure, even though mechanisms remain unclear. To confirm these findings, further evidence is required regarding changes in site-specific histone marks and DNA methylation together with their long-term effects on physiological outcomes.


Assuntos
Embrião não Mamífero/metabolismo , Epigênese Genética , Fígado/metabolismo , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Animais , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/genética , Embrião não Mamífero/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Fígado/efeitos dos fármacos , Testes de Toxicidade Aguda , Transcrição Genética/efeitos dos fármacos
8.
Aquat Toxicol ; 215: 105273, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31445453

RESUMO

The potential toxicity of nanoparticles (NPs) to the early stages of fish is still unclear. In this study, we investigated the toxic effects of silver (AgNPs) and copper nanoparticles (CuNPs) on lateral-line hair cells of zebrafish embryos. Zebrafish embryos were incubated in different concentrations of AgNPs and CuNPs at 0˜96 h post-fertilization (hpf). Both AgNPs and CuNPs were found to cause toxic effects in zebrafish embryos in a dose-dependent manner. Values of the 96-h 50% lethal concentration (LC50) of AgNPs and CuNPs were 6.1 ppm (56.5 µM) and 2.61 ppm (41.1 µM), respectively. The number of FM1-43-labeled hair cells and the microstructure of hair bundles were significantly impaired by AgNPs [≥1 ppm (9.3 µM)] and CuNPs [≥0.01 ppm (0.16 µM)]. Ca2+ influxes at hair bundles of hair cells were measured with a scanning ion-selective microelectrode technique to evaluate the function of hair cells. AgNPs [≥0.1 ppm (0.9 µM)] and CuNPs [≥0.01 ppm (0.16 µM)] were both found to significantly reduce Ca2+ influxes. Similar toxic effects were also found in hatched embryos subjected to 4 h of exposure (96˜100 hpf) to AgNPs and CuNPs. This study revealed that lateral-line hair cells of zebrafish are susceptible to AgNPs and CuNPs, and these contaminants in aquatic environments could pose a threat to fish survival.


Assuntos
Cobre/toxicidade , Embrião não Mamífero/citologia , Células Ciliadas Auditivas/citologia , Sistema da Linha Lateral/embriologia , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Peixe-Zebra/embriologia , Animais , Embrião não Mamífero/anatomia & histologia , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/ultraestrutura , Exposição Ambiental , Células Ciliadas Auditivas/ultraestrutura , Dose Letal Mediana , Nanopartículas Metálicas/ultraestrutura , Análise de Sobrevida , Poluentes Químicos da Água/toxicidade
9.
Nat Cell Biol ; 21(8): 966-977, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31371827

RESUMO

Migrasomes are recently identified vesicular organelles that form on retraction fibres behind migrating cells. Whether migrasomes are present in vivo and, if so, the function of migrasomes in living organisms is unknown. Here, we show that migrasomes are formed during zebrafish gastrulation and signalling molecules, such as chemokines, are enriched in migrasomes. We further demonstrate that Tspan4 and Tspan7 are required for migrasome formation. Organ morphogenesis is impaired in zebrafish MZtspan4a and MZtspan7 mutants. Mechanistically, migrasomes are enriched on a cavity underneath the embryonic shield where they serve as chemoattractants to ensure the correct positioning of dorsal forerunner cells vegetally next to the embryonic shield, thereby affecting organ morphogenesis. Our study shows that migrasomes are signalling organelles that provide specific biochemical information to coordinate organ morphogenesis.


Assuntos
Embrião não Mamífero/metabolismo , Morfogênese/fisiologia , Organelas/metabolismo , Proteínas de Peixe-Zebra/genética , Animais , Padronização Corporal/fisiologia , Movimento Celular/genética , Movimento Celular/fisiologia , Desenvolvimento Embrionário/fisiologia , Gastrulação/fisiologia , Organelas/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Peixe-Zebra/embriologia
10.
Gene ; 718: 144049, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31430520

RESUMO

The role of epigenetics in development has garnered attention in recent years due to their ability to modulate the embryonic developmental gene expression in response to the environmental cues. The epigenetic mechanisms - DNA methylation, histone modification, and non-coding RNAs have a unique impact on vertebrate development. Zebrafish, a model vertebrate organism is being used widely in developmental studies due to their high fecundability and rapid organogenesis. With increased studies on various aspects of epigenetics in development, this review gives a glimpse of the major epigenetic modifications and their role in zebrafish development. In this review, the basic mechanism behind each modification followed by their status in zebrafish has been reviewed. Further, recent advancements in the epigenetic aspect of zebrafish development have been discussed.


Assuntos
Metilação de DNA/fisiologia , Embrião não Mamífero/embriologia , Desenvolvimento Embrionário/fisiologia , Epigênese Genética/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Peixe-Zebra/embriologia , Animais , Histonas/genética , Histonas/metabolismo , Processamento de Proteína Pós-Traducional/fisiologia , Peixe-Zebra/genética
11.
Adv Exp Med Biol ; 1155: 471-482, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468424

RESUMO

Endothelial cell dysfunction (ECD) is a broad term, which implies dysregulation of endothelial cell functions. Several factors contribute to ECD including high blood pressure, high cholesterol levels, diabetes, obesity, hyperglycemia, and advanced glycation end products (AGEs). The highly reactive dicarbonyl methylglyoxal (MGO) is mainly formed as byproduct of glycolysis. Therefore, high blood glucose levels result in increased MGO accumulation. Taurine-rich foods are considered to protect against various diseases including vasculopathy and to exert anti-aging effects. Here, we investigated the protective effect of hot water extract of Octopus ocellatus meat (OOM), which contains high amounts of taurine, on MGO-induced cell damage in human umbilical vein endothelial cells and zebrafish embryos. Hot water extract of OOMinhibited MGO-induced cytotoxicity and DNA damage, as well as AGEs accumulation. In addition, hot water extract of OOM protected against vascular damage in zebrafish embryos. These results suggest that hot water extract of OOM possesses protective activity against MGO-induced cytotoxicity in both umbilical vein endothelial cells and zebrafish embryos. Therefore, it could be used as a dietary source of an agent for the prevention of vascular diseases.


Assuntos
Extratos Celulares/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Octopodiformes/química , Aldeído Pirúvico/toxicidade , Taurina/farmacologia , Animais , Células Cultivadas , Embrião não Mamífero/efeitos dos fármacos , Humanos , Carne , Peixe-Zebra
12.
Adv Exp Med Biol ; 1155: 611-626, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468435

RESUMO

In this study, the antioxidant properties of Viviparus contectus (V. contectus) extract were evaluated for various radical scavenging activities, ferric reducing antioxidant power (FRAP), ABTS radical scavenging activity and oxygen radical absorbance capacity (ORAC). In addition, inhibition effect of the V. contectus extract against DNA scission induced by hydroxyl radical was measured. We also studied the protective effect of V. contectus extract against oxidative damage through measurements of intracellular reactive oxygen species (ROS) in Chang cells and zebrafish embryo. We found that V. contectus extract contains strong radical scavenging activities and antioxidant properties, which prevent tert-butylhydroperoxide (t-BHP)-induced oxidative stress, enhance cell viability, reduce ROS production, inhibit oxidative damage and improve mitochondrial function in Chang cells. Also, we determined that the V. contectus extract reduced ROS production mediated by t-BHP induced oxidative stress on zebrafish embryo.


Assuntos
Antioxidantes/farmacologia , Extratos Celulares/farmacologia , Gastrópodes/química , Estresse Oxidativo , Animais , Linhagem Celular , Embrião não Mamífero , Humanos , Espécies Reativas de Oxigênio/metabolismo , Peixe-Zebra , terc-Butil Hidroperóxido
13.
Int J Nanomedicine ; 14: 4529-4539, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31417256

RESUMO

Purpose: Here, we fabricated two plasmonic 2D Ti3C2Tx-based nanocomposites (Au/MXene and Au/Fe3O4/MXene) with similarly high anti-cancer photothermal therapy (PTT) capabilities, but with less in vivo toxicity than a pure MXene. Methods: Au/MXene was synthesized by in situ reduction of tetrachloroauric acid using NaBH4 on Ti3C2Tx flakes. For targeted PTT, magnetic Au/Fe3O4/MXene was synthesized via a reaction between freshly prepared magnetite Fe3O4 NPs and MXene solution, followed by in situ integration of gold nanoparticles (AuNPs). Results: Morphological characterization by XRD, SEM, and TEM revealed the successful synthesis of Au/MXene and Au/Fe3O4/MXene. Both new composites exhibited a significant in vitro dose-dependent PTT effect against human breast cancer cells MCF7. Interestingly, in vivo acute toxicity assays using zebrafish embryos indicated that Au/MXene and Au/Fe3O4/MXene had less embryonic mortality (LC50 ≫ 1000 µg/mL) than pure MXene (LC50=257.46 µg/mL). Conclusion: Our new Au/MXene and Au/Fe3O4/MXene nanocomposites could be safer and more suitable than the pure MXene for biomedical applications, especially when targeted PTT is warranted.


Assuntos
Hipertermia Induzida , Nanocompostos/uso terapêutico , Fototerapia , Titânio/química , Testes de Toxicidade Aguda , Animais , Sobrevivência Celular/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Humanos , Células MCF-7 , Nanocompostos/ultraestrutura , Teratogênios/toxicidade , Difração de Raios X , Peixe-Zebra
14.
DNA Cell Biol ; 38(10): 1100-1111, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31418589

RESUMO

Members of the Sox gene family play crucial roles during reproduction and development, but their genome-wide identification has not yet been performed in large yellow croaker, Larimichthys crocea. In this study, a total of 26 members of the Sox gene family were identified from the genome of large yellow croaker and classified into seven subgroups based on the conserved HMG-box domain they contain. Among the identified Sox gene family members, eight belonged to the SoxB subgroup (five in B1 and three in B2), four belonged to the SoxC subgroup, four belonged to the SoxD subgroup, six belonged to the SoxE subgroup, three belonged to the SoxF subgroup, and one belonged to the SoxK subgroup. During evolution, members of the SoxE subgroup (Sox8, Sox9, Sox10), Sox1, Sox4, Sox6, and Sox11 evolved into two copies, which may be a result of teleost-specific whole-genome duplication. Sox genes were distributed unevenly across 15 chromosomes. The number of introns in large yellow croaker Sox genes varied from 0 to 14. Results of the expression profile during embryogenesis revealed that most of the members of the Sox gene family had lower expression, except several Sox genes, and expression patterns also differed among each Sox gene group and duplicated gene. This study systematically characterized and analyzed the Sox gene family in large yellow croaker and provided new insights into its function during embryogenesis.


Assuntos
Proteínas de Peixes/genética , Regulação da Expressão Gênica no Desenvolvimento , Genoma , Perciformes/genética , Filogenia , Fatores de Transcrição SOXB1/genética , Sequência de Aminoácidos , Animais , Evolução Biológica , Mapeamento Cromossômico , Biologia Computacional , Embrião não Mamífero , Desenvolvimento Embrionário , Éxons , Proteínas de Peixes/classificação , Duplicação Gênica , Íntrons , Família Multigênica , Perciformes/classificação , Isoformas de Proteínas/classificação , Isoformas de Proteínas/genética , Fatores de Transcrição SOXB1/classificação , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
15.
Aquat Toxicol ; 214: 105263, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31376794

RESUMO

The potential toxicity of silver nanoparticles (AgNPs) to the early stages of fish is still unclear. This study used zebrafish embryos as a model to investigate the toxic effects of AgNPs on ion regulation by skin ionocytes. Zebrafish embryos were exposed to AgNPs for 96 h (4-100 h post-fertilization (hpf)) or 4 h (96-100 hpf). After 96 h of exposure to 5 and 10 mg/L AgNPs, survival rates had decreased to 42% and 0%, respectively; the body length had also significantly decreased at 5 mg/L. Whole-body Na+ and K+ contents significantly decreased at 1 and 3 mg/L, while Ca2+ contents decreased at ≥0.1 mg/L. H+ secretion by the skin significantly decreased at 1 mg/L. The density of skin ionocytes labeled with rhodamine 123 (a mitochondrion marker) decreased by 25% and 55% at 1 and 3 mg/L, respectively; and 54% of ionocytes (at 3 mg/L) were deformed from an oval to a spinous shape. After 4 h of exposure to 1 and 5 mg/L, whole-body Na+ and Ca2+ contents, H+ secretion, and density of ionocytes had also significantly decreased. This study revealed the toxicity of AgNPs to skin ionocytes and ion regulation in the early stages of zebrafish embryos.


Assuntos
Embrião não Mamífero/metabolismo , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Peixe-Zebra/embriologia , Ácidos/metabolismo , Animais , Contagem de Células , Forma Celular/efeitos dos fármacos , Embrião não Mamífero/citologia , Embrião não Mamífero/efeitos dos fármacos , Íons , Larva/efeitos dos fármacos , Análise de Sobrevida , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/anatomia & histologia
16.
Environ Pollut ; 254(Pt A): 112947, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31400664

RESUMO

One of the current main challenges faced by the scientific community is concerning the fate and toxicity of plastics, due to both the well-known threats made by larger plastic items spreading in ecosystems and their fragmentation into micro- and nanoparticles. Since the chemical and physical characteristics of these smaller plastic fragments are markedly different with respect to their bulk product, the potential toxicological effects in the environment need to be deeply investigated. To partially fill this gap of knowledge, the aim of this study was to evaluate the polystyrene nanobead intake in the tissues of zebrafish (Danio rerio) embryos and their related toxicity. Embryos at 72 h post fertilization (hpf) were exposed for 48 h to 0.5 µm fluorescent polystyrene nanobeads at a concentration of 1 mg L-1. Confocal microscopy was employed to investigate nanoplastic ingestion and tissue infiltration, while potential sub-lethal effects were evaluated by measuring several endpoints, which covered the adverse effects at the molecular (protein carbonylation), cellular (P-glycoprotein, activity of several antioxidant/detoxifying enzymes) and organism levels by evaluating of possible changes in the embryos' swimming behaviour. Imaging observations clearly highlighted the nanoplastics' uptake, showing nanobeads not only in the digestive tract, but also migrating to other tissues through the gut epithelium. Biomarker analyses revealed a significant decrease in cyclooxygenase activity and an induction of superoxide dismutase. The behavioural test highlighted a significant (p < 0.05) variation in the turn angle between the control and exposed embryos. This study points out the capability of nanoplastics to infiltrate zebrafish embryo tissues, even after a short exposure, thus suggesting the need for deeper investigations following longer exposure times, and highlighting the potential of nanoplastics to cause toxicological effects on freshwater organisms, at the organism level.


Assuntos
Embrião não Mamífero/metabolismo , Poliestirenos/metabolismo , Poluentes Químicos da Água/metabolismo , Peixe-Zebra/embriologia , Animais , Antioxidantes/farmacologia , Organismos Aquáticos , Ecossistema , Embrião não Mamífero/efeitos dos fármacos , Nanopartículas/química , Plásticos/farmacologia , Poliestirenos/química , Poliestirenos/toxicidade , Superóxido Dismutase , Poluentes Químicos da Água/toxicidade
17.
Ecotoxicol Environ Saf ; 183: 109566, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31437728

RESUMO

Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants. Biomonitoring studies have shown widespread presence of PBDEs in humans and their accumulation in food chain cause concern to human health, especially for foetus and infant development. The early-life stages are generally considered more sensitive to exposure to toxic compounds than juvenile or adults. For this reason the aim of this study was to evaluate the effects of the three most environmentally relevant BDE (BDE- 47, 99 and 209) on zebrafish embryos. The fish embryo toxicity (FET) OECD tests on zebrafish were performed followed by histopathogical examination to assess morphological changes. The gene expression of the thyroid stimulating hormone ß (Tshß), the transport proteins transthyretin (Ttr) and thyroxine-binding globulin (Tbg) as well as the enzyme iodothyronine deiodinase 1 (Dio1) was also assessed by Real-time PCR. BDE-47 and BDE-99 showed an increase of the severity of the effects at the lower concentrations while for the BDE-209 the effects were higher to the high concentrations. Although all compounds did not show any acute toxicity for none of the concentrations tested, they reported interesting sub-acute lesions, including yolk and pericardial edema, tail and head malformation, reduced and extremely reduced heart beat rate, blood stasis and spinal curvature, with the highest percentage recorded for BDE-209. Cardiac edema, damage of eye structure and hydrocephaly were confirmed also by histophatological examination. Furthermore, a toxic and dose-dependent liver vacuolization in BDE-209 was observed in all experimental groups. Although no statistically significant difference in gene expression was observed, BDE-209 up-regulated only Dio1 while the other congeners induced Tshß, Ttr, Tbg and Dio1. Overall, this research highlighted that exposure to BDE-47, BDE-99 and BDE-209 at realistic concentrations caused lethal and sub-lethal alterations and impaired genes involved in thyroid hormones homeostasis leading to abnormal development of zebrafish embryos.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Monitoramento Ambiental/métodos , Retardadores de Chama/toxicidade , Expressão Gênica/efeitos dos fármacos , Éteres Difenil Halogenados/toxicidade , Peixe-Zebra , Adulto , Animais , Relação Dose-Resposta a Droga , Embrião não Mamífero/patologia , Retardadores de Chama/análise , Éteres Difenil Halogenados/análise , Humanos , Hormônios Tireóideos/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismo
18.
Nat Commun ; 10(1): 3219, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363093

RESUMO

The position, shape and number of transcription start sites (TSS) are critical determinants of gene regulation. Most methods developed to detect TSSs and study promoter usage are, however, of limited use in studies that demand quantification of expression changes between two or more groups. In this study, we combine high-resolution detection of transcription start sites and differential expression analysis using a simplified TSS quantification protocol, MAPCap (Multiplexed Affinity Purification of Capped RNA) along with the software icetea . Applying MAPCap on developing Drosophila melanogaster embryos and larvae, we detected stage and sex-specific promoter and enhancer activity and quantify the effect of mutants of maleless (MLE) helicase at X-chromosomal promoters. We observe that MLE mutation leads to a median 1.9 fold drop in expression of X-chromosome promoters and affects the expression of several TSSs with a sexually dimorphic expression on autosomes. Our results provide quantitative insights into promoter activity during dosage compensation.


Assuntos
Drosophila melanogaster/genética , Regulação da Expressão Gênica no Desenvolvimento , Capuzes de RNA/isolamento & purificação , Sítio de Iniciação de Transcrição , Animais , Animais Geneticamente Modificados , Linhagem Celular , Proteínas Cromossômicas não Histona/genética , Cromossomos de Insetos/genética , Biologia Computacional/métodos , DNA Helicases/genética , Compensação de Dosagem (Genética) , Proteínas de Drosophila/genética , Drosophila melanogaster/crescimento & desenvolvimento , Embrião não Mamífero , Desenvolvimento Embrionário/genética , Perfilação da Expressão Gênica/métodos , Genes de Insetos , Larva/genética , Larva/crescimento & desenvolvimento , Mutação , Regiões Promotoras Genéticas , Capuzes de RNA/genética , Software , Fatores de Transcrição/genética , Cromossomo X/genética
19.
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
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