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1.
Gene ; 735: 144388, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-31987905

RESUMO

Nap1l1 gene encodes a tissue specific nucleosome assembly protein and is essential for tissue development. Here, we report the generation and characterization of a nap1l1 transgenic reporter in zebrafish model. We showed that a 5-kilobase (kb) genomic fragment immediately upstream of the nap1l1 gene transcription initiation site is capable of targeting the nucleic enhanced green fluorescence protein (EGFP) expression initially to central nervous system and subsequently to lateral line neuromasts, cardiomyocytes, and paraxial vessels, where the endogenous nap1l1 normally expresses with only a few exception. In adulthood, zebrafish nap1l1 promoter-driving nEGFP is predominantly expressed in lateral line system, liver, and ovary, but not in heart. Therefore, this novel transgenic reporter line, Tg(nap1l1:nEGFP)zs102, would be a valuable tool for studying the development and regeneration of lateral line system and also for investigating cardiac development.


Assuntos
Genes Reporter , Sistema da Linha Lateral/metabolismo , Proteína 1 de Modelagem do Nucleossomo/genética , Transgenes , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Sistema da Linha Lateral/crescimento & desenvolvimento , Proteína 1 de Modelagem do Nucleossomo/metabolismo , Regiões Promotoras Genéticas , Peixe-Zebra/crescimento & desenvolvimento , Proteínas de Peixe-Zebra/metabolismo
2.
Chemosphere ; 242: 125285, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896209

RESUMO

The aim of this study was to assess the long-term effects of synthetic progestin norethindrone (NET) on the growth, reproductive histology, and transcriptional expression profiles of genes associated with the hypothalamic-pituitary-gonadal (HPG) axis and germ cells in adult zebrafish. Adult zebrafish were exposed to 7, 84 and 810 ng/L NET for 90 days. The results showed that exposure to 810 ng/L NET caused a significant decrease in growth of females and males. The ovary weight and GSI was significantly reduced by NET at concentrations of 84 or 810 ng/L, which came along with the delay of ovary maturation in females. However, NET at all treatments resulted in acceleration of sperm maturation in males. In the ovaries of females, a strong inhibition of cyp19a1a gene was observed following exposure to NET at 810 ng/L. Similarly, NET at the highest treatment led to a significant down-regulation of cyp17, cyp19a1a, vasa, nanos1, dazl and dmc1 genes in the testes of males. Taken together, the overall results demonstrated that NET could impact growth and gonadal maturation, with significant alterations of transcriptional expression genes along HPG axis and germ cells.


Assuntos
Expressão Gênica/efeitos dos fármacos , Noretindrona/toxicidade , Progestinas/toxicidade , Poluentes Químicos da Água/toxicidade , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento , Animais , Regulação para Baixo , Feminino , Células Germinativas/efeitos dos fármacos , Gônadas/efeitos dos fármacos , Masculino , Ovário/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Diferenciação Sexual/efeitos dos fármacos , Testículo/efeitos dos fármacos , Peixe-Zebra/genética
3.
Nat Commun ; 11(1): 168, 2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31924754

RESUMO

Variations in transcription start site (TSS) selection reflect diversity of preinitiation complexes and can impact on post-transcriptional RNA fates. Most metazoan polymerase II-transcribed genes carry canonical initiation with pyrimidine/purine (YR) dinucleotide, while translation machinery-associated genes carry polypyrimidine initiator (5'-TOP or TCT). By addressing the developmental regulation of TSS selection in zebrafish we uncovered a class of dual-initiation promoters in thousands of genes, including snoRNA host genes. 5'-TOP/TCT initiation is intertwined with canonical initiation and used divergently in hundreds of dual-initiation promoters during maternal to zygotic transition. Dual-initiation in snoRNA host genes selectively generates host and snoRNA with often different spatio-temporal expression. Dual-initiation promoters are pervasive in human and fruit fly, reflecting evolutionary conservation. We propose that dual-initiation on shared promoters represents a composite promoter architecture, which can function both coordinately and divergently to diversify RNAs.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Regiões Promotoras Genéticas/genética , Sítio de Iniciação de Transcrição , Transcrição Genética , Animais , Sequência de Bases , Drosophila/genética , Drosophila/crescimento & desenvolvimento , Humanos , RNA/genética , RNA/fisiologia , RNA Nucleolar Pequeno/genética , RNA Nucleolar Pequeno/metabolismo , Pequeno RNA não Traduzido/genética , Pequeno RNA não Traduzido/fisiologia , RNA não Traduzido/genética , RNA não Traduzido/fisiologia , Elementos Reguladores de Transcrição , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento , Zigoto
4.
Chemosphere ; 242: 125209, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31677519

RESUMO

The fungicide myclobutanil (MYC) is a common contaminant found in surface water. The aim of this study was to determine the acute toxicity, developmental effects, bioconcentration factor (BCF) and potential bio-molecular mechanisms of MYC toxicity in zebrafish. Susceptibility to MYC toxicity was life-stage dependent with adult fish being the most sensitive (96 h-LC50, 6.34 mg/L) followed by 72 h post-hatch (hph) larvae (8.90 mg/L), 12 hph larvae (20.53 mg/L) and embryos (42.54 mg/L). Zebrafish embryos and larvae (12 hph) responded with decreased hatching, heartbeat and growth, as well as abnormal spontaneous movement and development. BCFs were calculated by quantifying MYC concentrations from different tissues of adult zebrafish exposed to MYC for up to 11 days. Highest BCFs were obtained from gills (18.25 ±â€¯0.07), followed by viscera (16.78 ±â€¯0.04), head (13.13 ±â€¯0.08) and muscle (8.96 ±â€¯0.10). MYC (0.5 mg/L) inhibited gene expression related to cholesterol synthesis pathway, including 24-dehydrocholesterol reductase (DHCR24), 7-dehydrocholesterol reductase (DHCR7), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCRa), HMGCRb, farnesyl-diphosphate farnesyltransferase 1(FDFT1), squa-lene epoxidase (SQLE), isopentenyl-diphosphate delta isomerase 1 (IDI1) and CYP51, while no cholesterol changes were observed in the MYC treated group. These results will contribute to the literature assessing the environmental risk of MYC in aquatic environment.


Assuntos
Colesterol/biossíntese , Nitrilos/toxicidade , Triazóis/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/crescimento & desenvolvimento , Animais , Bioacumulação , Colesterol/genética , Embrião não Mamífero/efeitos dos fármacos , Feminino , Fungicidas Industriais/toxicidade , Larva/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Masculino , Fatores Sexuais , Peixe-Zebra/metabolismo
5.
Chemosphere ; 241: 124980, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31600620

RESUMO

Azoxystrobin and pyraclostrobin are broad spectrum strobilurin fungicides that have been measured in the aquatic environment. Strobilurins inhibit mitochondrial respiration by binding to the mitochondrial respiratory complex III. The goal of this study was to investigate mitochondrial dysfunction and oxidative stress in the developing zebrafish from exposure to azoxystrobin and pyraclostrobin. Exposure studies were performed where zebrafish embryos were exposed to azoxystrobin and pyraclostrobin at 0.1, 10, 100 µg/L from 4 hpf to 48 hpf to measure mitochondrial dysfunction and oxidative stress mRNA transcripts, and 5 dpf to measure movement, growth, oxygen consumption, enzymatic activities, and mRNA transcripts. Results from this study indicated that there was a significant reduction in both basal and maximal respiration at 48 hpf in zebrafish exposed to 100 µg/L of pyraclostrobin. There was no difference in oxidative stress or apoptotic mRNA transcripts at 48 hpf, indicating that the two strobilurins were acting first on mitochondrial function and not directly through oxidative stress. At 5 dpf, standard body length was significantly reduced with exposure to pyraclostrobin and azoxystrobin exposure as compared to the control. These reductions in apical endpoints corresponded with increases in oxidative stress and apoptotic mRNA transcripts in treatment groups at 5 dpf indicating that strobilurins' exposure followed the adverse outcome pathway for mito-toxicants. Our results indicate that strobilurins can decrease mitochondrial function, which in turn lead to diminished growth and movement.


Assuntos
Estrobilurinas/farmacologia , Peixe-Zebra/crescimento & desenvolvimento , Animais , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário , Fungicidas Industriais/toxicidade , Larva/efeitos dos fármacos , Mitocôndrias/metabolismo , Estresse Oxidativo , Pirimidinas/farmacologia , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo
6.
Cell Mol Life Sci ; 77(1): 161-177, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31161284

RESUMO

Peripheral nervous system development involves a tight coordination of neuronal birth and death and a substantial remodelling of the myelinating glia cytoskeleton to achieve myelin wrapping of its projecting axons. However, how these processes are coordinated through time is still not understood. We have identified engulfment and cell motility 1, Elmo1, as a novel component that regulates (i) neuronal numbers within the Posterior Lateral Line ganglion and (ii) radial sorting of axons by Schwann cells (SC) and myelination in the PLL system in zebrafish. Our results show that neuronal and myelination defects observed in elmo1 mutant are rescued through small GTPase Rac1 activation. Inhibiting macrophage development leads to a decrease in neuronal numbers, while peripheral myelination is intact. However, elmo1 mutants do not show defective macrophage activity, suggesting a role for Elmo1 in PLLg neuronal development and SC myelination independent of macrophages. Forcing early Elmo1 and Rac1 expression specifically within SCs rescues elmo1-/- myelination defects, highlighting an autonomous role for Elmo1 and Rac1 in radial sorting of axons by SCs and myelination. This uncovers a previously unknown function of Elmo1 that regulates fundamental aspects of PNS development.


Assuntos
Bainha de Mielina/metabolismo , Neurogênese , Neurônios/citologia , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/crescimento & desenvolvimento , Proteínas rac1 de Ligação ao GTP/metabolismo , Animais , Apoptose , Axônios/metabolismo , Axônios/ultraestrutura , Movimento Celular , Neurônios/metabolismo , Neurônios/ultraestrutura , Nervos Periféricos/crescimento & desenvolvimento , Nervos Periféricos/ultraestrutura , Células de Schwann/citologia , Células de Schwann/metabolismo , Células de Schwann/ultraestrutura
7.
Ecotoxicol Environ Saf ; 188: 109870, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31683046

RESUMO

BPF, a substitute of BPA, has been widely detected in environment and human bodies. Although the genotoxicity, endocrine disrupting effects, reproductive toxicity of BPF has been well documented, its neurodevelopmental toxicity still remains nebulous. In our study, zebrafish embryos were exposed to BPF treatment (0, 7, 70 and 700 µg/L) for 3 or 6 days. Our results showed that BPF exposure markedly decreased zebrafish locomotor behavior, increased oxidative stress, promoted apoptosis and altered brain structure in zebrafish. In addition, the expressions of neurodevelopment related genes were also downregulated upon BPF treatment. In conclusion, our results systematically demonstrated the developmental neurotoxicity of BPF in zebrafish.


Assuntos
Compostos Benzidrílicos/toxicidade , Encéfalo/efeitos dos fármacos , Fenóis/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/embriologia , Animais , Apoptose/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Exposição Ambiental , Feminino , Locomoção/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Peixe-Zebra/crescimento & desenvolvimento
8.
Chemosphere ; 239: 124698, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31493753

RESUMO

Synthetic silver nanoparticles (AgNPs) are being extensively used in our daily lives; however, they may also pose a risk to public health and environment. Nowadays, biological AgNPs are considered an excellent alternative, since their synthesis occurs by a green technology of low cost and easy scaling. However, studies with these biological nanomaterials (NM) are still limited. Thus, a more careful assessment of their industrial application, economic feasibility and ecotoxicological impacts is crucial. The aim of this study was to investigate the effects of different concentrations of mangrove fungus Aspergillus tubingensis AgNPs on the aerobic heterotrophs soil microorganisms, rice seeds (Oryza sativa) and zebrafish (Danio rerio). Biogenic AgNPs were less harmful for soil microbiota compared to AgNO3. On rice seeds, the AgNPs displayed a dose-dependent inhibitory effect on germination and their subsequent growth and development. The percentage of inhibition of rice seed germination was 30, 69 and 80% for 0.01, 0.1 and 0.5 mM AgNPs, respectively. After 24 h of AgNPs exposition at a limit concentration of 0.2 mM, it did not induce mortality of the zebrafish D. rerio. Overall, A. tubingensis AgNPs can be considered as a suitable alternative to synthetic nanoparticles.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/farmacologia , Solo/química , Animais , Aspergillus/metabolismo , Germinação/efeitos dos fármacos , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Oryza/fisiologia , Sementes/efeitos dos fármacos , Peixe-Zebra/crescimento & desenvolvimento
9.
Aquat Toxicol ; 219: 105384, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31869577

RESUMO

Tritium (3H), a radioactive isotope of hydrogen, is ubiquitously present in the environment. In a previous study, we highlighted a mis-regulation of genes involved in muscle contraction, eye transparency and response to DNA damages after exposure of zebrafish embryo-larvae from 3 hpf to 96 hpf at 0.4 and 4 mGy/h of tritiated water (HTO). The present study aimed to link this gene mis-regulation to responses observed at higher biological levels. Analyses on spontaneous tail movement, locomotor activity and heart rate were performed. Histological sections of eyes were made to evaluate the impact of HTO on eye transparency and whole embryo immunostainings were realized to assess DNA double strand breaks repair using gamma-H2AX foci. We found a decrease of basal velocity as well as a decrease of response in 96 hpf larvae exposed at 0.4 mGy/h after a tactile stimulus as compared to controls. Histological sections of larvae eyes performed after the exposure to 4 mGy/h did not show obvious differences in lens transparency or retinal development between contaminated and control organisms. Gamma-H2AX foci detection revealed no differences in the number of foci between contaminated organisms and controls, for both dose rates. Overall, results highlighted more detrimental effects of HTO exposure on locomotor behavior in 96 hpf larvae exposed at the lowest dose rate. Those results could be linked to mis-regulation of genes involved in muscle contraction found in a previous study at the same dose rate. It appears that not all effects found at the molecular scale were confirmed using higher biological scales. These results could be due to a delay between gene expression modulation and the onset of physiological disruption or homeostatic mechanisms to deal with tritium effects. However, crossing data from different scales highlighted new pathways to explore, i.e. neurotoxic pathways, for better understanding HTO effects on organisms.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Larva/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Trítio/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/crescimento & desenvolvimento , Animais , Dano ao DNA , Olho/efeitos dos fármacos , Olho/crescimento & desenvolvimento , Olho/patologia , Larva/genética , Peixe-Zebra/genética
10.
PLoS Genet ; 15(12): e1008507, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31790396

RESUMO

Deleterious genetic mutations allow developmental biologists to understand how genes control development. However, not all loss of function genetic mutants develop phenotypic changes. Many deleterious mutations only produce a phenotype in a subset of mutant individuals, a phenomenon known as incomplete penetrance. Incomplete penetrance can confound analyses of gene function and our understanding of this widespread phenomenon remains inadequate. To better understand what controls penetrance, we capitalized on the zebrafish mef2ca mutant which produces craniofacial phenotypes with variable penetrance. Starting with a characterized mef2ca loss of function mutant allele, we used classical selective breeding methods to generate zebrafish strains in which mutant-associated phenotypes consistently appear with low or high penetrance. Strikingly, our selective breeding for low penetrance converted the mef2ca mutant allele behavior from homozygous lethal to homozygous viable. Meanwhile, selective breeding for high penetrance converted the mef2ca mutant allele from fully recessive to partially dominant. Comparing the selectively-bred low- and high-penetrance strains revealed that the strains initially respond similarly to the mutation, but then gene expression differences between strains emerge during development. Thus, altered temporal genetic circuitry can manifest through selective pressure to modify mutant penetrance. Specifically, we demonstrate differences in Notch signaling between strains, and further show that experimental manipulation of the Notch pathway phenocopies penetrance changes occurring through selective breeding. This study provides evidence that penetrance is inherited as a liability-threshold trait. Our finding that vertebrate animals can overcome a deleterious mutation by tuning genetic circuitry complements other reported mechanisms of overcoming deleterious mutations such as transcriptional adaptation of compensatory genes, alternative mRNA splicing, and maternal deposition of wild-type transcripts, which are not observed in our system. The selective breeding approach and the resultant genetic circuitry change we uncovered advances and expands our current understanding of genetic and developmental resilience.


Assuntos
Fatores de Transcrição MEF2/genética , Fatores de Transcrição MEF2/metabolismo , Receptores Notch/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Animais , Epistasia Genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/genética , Mutação com Perda de Função , Masculino , Ossificação Heterotópica/genética , Penetrância , Fenótipo , Seleção Artificial , Transdução de Sinais , Fatores de Transcrição/genética , Peixe-Zebra/crescimento & desenvolvimento , Proteínas de Peixe-Zebra/genética
11.
Aquat Toxicol ; 217: 105345, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31715477

RESUMO

Lethal and sublethal effects of trinitrotoluene (TNT) and its degradation products 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) to zebrafish embryos (Danio rerio) were investigated in a 120 h exposure scenario. Lethal concentrations (LC50) were 4.5 mg/l for TNT, 13.4 mg/l for 2-ADNT and 14.4 mg/l for 4-ADNT. Embryos exposed to 2-ADNT or 4-ADNT revealed a high proportion of chorda deformations among the surviving individuals. Genotoxicity of the nitroaromatic compounds in zebrafish embryos was investigated by comet assay isolating cells from whole embryos after 48 h in vivo exposure. Significant genotoxicity was induced by all three compounds tested, in comparison to the corresponding controls at 0.1 mg/l and 1.0 mg/l as lowest tested concentrations. The genotoxicity caused by TNT was about three to four times higher than that of 2-ADNT and 4-ADNT. To our knowledge, this is the first study demonstrating the genotoxicity of TNT in fish embryos by in vivo exposure. The results are discussed in the context of dumped munition in the marine environment.


Assuntos
Dano ao DNA , Embrião não Mamífero/efeitos dos fármacos , Mutagênicos/toxicidade , Trinitrotolueno/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/crescimento & desenvolvimento , Compostos de Anilina/toxicidade , Animais , Peixe-Zebra/genética
12.
J Plant Physiol ; 243: 153058, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31715490

RESUMO

Boron (B) deficiency affects the development of Pisum sativum nodules and Arabidopsis thaliana root meristems. Both organs show an alteration of cell differentiation that result in the development of tumor-like structures. The fact that B in plants is not only able to interact with components of the cell wall but also with membrane-associated glycoconjugates, led us to analyze changes in high mannose type N-glycans (HMNG). The affinoblots with concanavalin A revealed alterations in the N-glycosylation pattern during early development of nodules and roots under B deprivation. Besides, there is increasing evidence of a B role in animal physiology that brought us to investigate the impact of B deficiency on Danio rerio (zebrafish) development. When B deficiency was induced prior to early cleavage stages, embryos developed as an abnormal undifferentiated mass of cells. Additionally, when B was removed at post-hatching, larvae undergo aberrant organogenesis. Resembling the phenomenon described in plants, alteration of the N-glycosylation pattern occurred in B-deficient zebrafish larvae prior to organogenesis. Overall, these results support a common function of B in plants and animals associated with glycosylation that might be important for cell signaling and cell fate determination during development.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Boro/deficiência , Organogênese Vegetal/efeitos dos fármacos , Ervilhas/crescimento & desenvolvimento , Polissacarídeos/metabolismo , Peixe-Zebra/crescimento & desenvolvimento , Animais , Arabidopsis/metabolismo , Glicosilação , Manose/metabolismo , Ervilhas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Nódulos Radiculares de Plantas/crescimento & desenvolvimento , Nódulos Radiculares de Plantas/metabolismo , Peixe-Zebra/metabolismo
13.
J Agric Food Chem ; 67(45): 12348-12356, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31638788

RESUMO

Carbosulfan is a carbamate insecticide that has been widely used in agriculture. However, studies showed that carbosulfan could be highly toxic to aquatic organisms. The metabolism of carbosulfan in adult zebrafish is still largely unexplored, and the metabolites in individual or in combination may pose a potential threat to zebrafish. In the present study, the bioaccumulation and metabolism of carbosulfan in zebrafish (Danio rerio) were assessed, and the main metabolites, including carbofuran and 3-hydroxycarbofuran, were determined. The toxicity of carbosulfan and its metabolites individually or in combination to zebrafish was also investigated. The bioaccumulation and metabolism experiment indicated that carbosulfan was not highly accumulated in zebrafish, with a bioaccumulation factor of 18 after being exposed to carbosulfan for 15 days, and the metabolism was fast, with a half-life of 1.63 d. The two main metabolites were relatively persistent, with half-lives of 3.33 and 5.68 d for carbofuran and 3-hydroxycarbofuran, respectively. The acute toxicity assay showed that carbofuran and 3-hydroxycarbofuran had 96-h LC50 values of 0.15 and 0.36 mg/L, showing them to be more toxic than carbosulfan (96-h LC50 = 0.53 mg/L). Combinations of binary or ternary mixtures of carbosulfan and its metabolites displayed coincident synergistic effects on acute toxicity, with additive index (AI) values of 1.9-14.3. In the livers and gills of zebrafish exposed to carbosulfan, carbofuran, and 3-hydroxycarbofuran, activities of catalase, superoxide dismutase, and glutathione-S-transferase were significantly changed in most cases, and the content of malondialdehyde was greatly increased, indicating that carbosulfan and its metabolites induced varying degrees of oxidative stress. The metabolites were more persistent and toxic to zebrafish and exhibit coincident synergistic effects in combination. These results can provide evidence for the potential risk of pesticides and highlight the importance of a systematic assessment for the combination of the precursor and its metabolites.


Assuntos
Carbamatos/metabolismo , Carbamatos/toxicidade , Inseticidas/metabolismo , Inseticidas/toxicidade , Peixe-Zebra/metabolismo , Animais , Carbofurano/análogos & derivados , Carbofurano/metabolismo , Carbofurano/toxicidade , Catalase , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Dose Letal Mediana , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
14.
Genes Genet Syst ; 94(4): 177-179, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31582646

RESUMO

Integrins, transmembrane molecules that facilitate cell-to-cell and cell-to-extracellular matrix interactions, are heterodimers that consist of an α- and ß-subunit. The integrin α4 gene (itgα4) is expressed in various type of cells and tissues. Its biochemical functions and physiological roles have been revealed using cultured cell assays. In contrast, the primary effect caused by itgα4 deletion on vertebrate development is poorly understood, because knockout mice exhibit multiple defects that can lead to embryonic lethality in the uterus. Zebrafish are a convenient vertebrate model to investigate morphogenesis during embryogenesis, because of their external fertilization and subsequent development outside the female's body. Here, we generated a zebrafish mutant line named itgα4 ko108 using the CRISPR/Cas9 genome editing system; the mutant genome harbored an approximately 2.0-kb deletion in the itgα4 locus. A truncated transcript was detected in itgα4 (+/-) or (-/-) fish but not in (+/+) fish. The mutant transcript was hypothesized to encode a truncated Itgα4 protein due to a premature stop codon. itgα4 (-/-) embryos obtained from the mating of heterozygous parents exhibited no apparent phenotype during development at 24 hours post-fertilization (hpf). However, approximately half of them exhibited cephalic hemorrhage at 48 hpf. The incidence ratio was significantly higher than that in (+/+) or (+/-) embryos. Embryonic hemorrhage has also been reported previously in Itgα4 knockout mice. In contrast, embryonic lethality with the other defects reported in the knockout mice was not observed in our zebrafish model. Therefore, the mutant line itgα4 ko108 should be a useful model to investigate a physiological function for Itgα4 in the blood circulation system.


Assuntos
Desenvolvimento Embrionário/genética , Integrina alfa4/genética , Morfogênese/genética , Peixe-Zebra/genética , Animais , Sistemas CRISPR-Cas/genética , Comunicação Celular/genética , Edição de Genes , Regulação da Expressão Gênica no Desenvolvimento/genética , Genoma/genética , Cabeça/crescimento & desenvolvimento , Cabeça/patologia , Hemorragia/fisiopatologia , Heterozigoto , Fenótipo , Peixe-Zebra/crescimento & desenvolvimento
15.
Bull Environ Contam Toxicol ; 103(6): 789-795, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31605158

RESUMO

Copper (Cu) bioavailability varies under water conditions. In the present study, the whole life of zebrafish was divided into three different life stages (larvae, juvenile and adult) based on the growth curve, then the influences of water hardness and dissolved organic carbon (DOC) concentration on the acute toxicity of zebrafish were respectively investigated. The results indicated that the life stages had significant effects on Cu toxicity. The larvae stage was less sensitive to Cu than both the juvenile and adult stages. With the increase of water hardness, the toxicity of Cu on zebrafish was decreased, a linear relationship was observed between water hardness and Cu toxicity, and the same was true for DOC concentration. The results showed that taking the 24 days juvenile zebrafish to study the water quality criteria of Cu was stable, sensitive and economical.


Assuntos
Cobre/toxicidade , Água Doce/química , Hidrocarbonetos/toxicidade , Larva/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/crescimento & desenvolvimento , Animais , Cobre/química , Dureza , Hidrocarbonetos/química , Solubilidade , Testes de Toxicidade Aguda , Poluentes Químicos da Água/química , Qualidade da Água/normas
16.
Mar Biotechnol (NY) ; 21(5): 671-682, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31502176

RESUMO

Primordial germ cells (PGCs) as the precursors of germ cells are responsible for transmitting genetic information to the next generation. Visualization of teleost PGCs in vivo is essential to research the origination and development of germ cells and facilitate further manipulation on PGCs isolation, cryopreservation, and surrogate breeding. In this study, artificially synthesized mRNAs constructed by fusing fluorescent protein coding region to the 3' untranslated region (3'UTR) of nanos3 or vasa (mCherry-Smnanos3 3'UTR or mCherry-Smvasa 3'UTR mRNA) were injected into turbot (Scophthalmus maximus) fertilized eggs for tracing PGCs. The results demonstrated that the fluorescent PGCs differentiated from somatic cells and aligned on both sides of the trunk at the early segmentation period, then migrated and located at the dorsal part of the gut where the gonad would form. In the same way, we also found that the zebrafish (Danio rerio) vasa 3'UTR could trace turbot PGCs, while the vasa 3'UTR s of marine medaka (Oryzias melastigma) and red seabream (Pagrus major) failed, although they could label the marine medaka PGCs. In addition, through comparative analysis, we discovered that some potential sequence elements in the3 'UTRs of nanos3 and vasa, such as GCACs, 62-bp U-rich regions and nucleotide 187-218 regions might be involved in PGCs stabilization. The results of this study provided an efficient, rapid, and specific non-transgenic approach for visualizing PGCs of economical marine fish in vivo.


Assuntos
Rastreamento de Células/métodos , Proteínas de Peixes/genética , Linguados/genética , Células Germinativas/metabolismo , Proteínas Recombinantes de Fusão/genética , Peixe-Zebra/genética , Regiões 3' não Traduzidas , Animais , Sequência de Bases , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Proteínas de Peixes/metabolismo , Linguados/crescimento & desenvolvimento , Linguados/metabolismo , Genes Reporter , Células Germinativas/citologia , Células Germinativas/crescimento & desenvolvimento , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Microinjeções , Conformação de Ácido Nucleico , Oryzias/genética , Oryzias/crescimento & desenvolvimento , Oryzias/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo , Zigoto
17.
Ecotoxicol Environ Saf ; 184: 109663, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31539807

RESUMO

Humidifier disinfectants have been widely used in Korea to prevent the growth of microorganisms in humidifier water. However, their use has been banned since 2011 after epidemiological studies reported humidifier disinfectant induced lung injury. In the present study, the developmental effects of exposure to two humidifier disinfectants (Oxy® and Wiselect) and their main component, polyhexamethylene guanidine (PHMG)-phosphate, were investigated in zebrafish embryos/larvae for seven days. The effects on triiodothyronine (T3) and thyroxine (T4) hormones, reactive oxygen species (ROS) generation, antioxidant enzyme activities, and changes in expression of the genes related to the hypothalamus-pituitary-thyroid (HPT) axis and oxidative stress were also investigated. Zebrafish embryos exposed to the highest concentration (amounts recommended for use by the manufacturers) of all tested humidifier disinfectants showed an increase in embryo coagulation, leading to death without hatching. Exposure to Oxy® and Wiselect resulted in significantly decreased body length, increased ROS generation and antioxidant enzyme activities, decreased T4, and up-regulated genes related to the HPT axis (trh, trß, and tpo) and oxidative damage (sod2 and gpx1b). The humidifier disinfectants and PHMG-phosphate could induce oxidative stress and disrupt thyroid hormone systems in zebrafish, leading to developmental retardation when used at sub-lethal concentrations. Potential effects of long-term exposure to humidifier disinfectants and mixture effects of several major components deserve further investigation.


Assuntos
Desinfetantes/toxicidade , Disruptores Endócrinos/toxicidade , Umidificadores/normas , Peixe-Zebra/crescimento & desenvolvimento , Animais , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , República da Coreia , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/crescimento & desenvolvimento , Hormônios Tireóideos/metabolismo
18.
Chemosphere ; 236: 124590, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31470984

RESUMO

Metamifop is a novel aryloxyphenoxy propionate (AOPP) herbicide that is widely applied in paddy fields, which will inevitably enter aquatic environments and pose a risk to aquatic organisms. However, the potential threat and toxicological mechanisms of metamifop in aquatic organisms are poorly understood. In this study, zebrafish embryos were used to investigate the potential developmental toxicity and mechanisms of metamifop. The results showed that metamifop exhibited high acute toxicity to zebrafish, with 96 h-LC50 values of 0.648 and 0.216 mg/L to embryos and larvae of 72 h post-hatching (hph), respectively. Decreased body lengths, heartbeat number, and hatching rates, and increased malformation rates of embryos were observed after 96 h of exposure to 0.38 mg/L or higher concentration of metamifop. Furthermore, oxidative stress was caused in embryos, with increased contents of reactive oxygen species (ROS) and malondialdehyde (MDA), and altered activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Metamifop exposure clearly triggered cell apoptosis in embryos, result in the increase of Caspase-3 and Caspase-9 activities and up-regulation of apoptosis-related genes (bax, p53, apaf1, caspase-3, and caspase-9). Additionally, the transcriptions of innate immune-related genes (il-8, il-1b, and ifn) were increased in the groups treated with 0.25 and 0.5 mg/L of metamifop. These results indicate that metamifop induced developmental toxicity in zebrafish, and the potential toxicological mechanisms were related to oxidative stress, cell apoptosis, and the innate immune responses in embryos.


Assuntos
Anilidas/toxicidade , Benzoxazóis/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Peixe-Zebra/metabolismo , Animais , Apoptose/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Herbicidas/metabolismo , Imunidade Inata/genética , Larva/efeitos dos fármacos , Larva/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Espécies Reativas de Oxigênio/metabolismo , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/embriologia , Peixe-Zebra/crescimento & desenvolvimento
19.
Genetics ; 213(2): 529-553, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31399485

RESUMO

Fetal mammalian testes secrete Anti-Müllerian hormone (Amh), which inhibits female reproductive tract (Müllerian duct) development. Amh also derives from mature mammalian ovarian follicles, which marks oocyte reserve and characterizes polycystic ovarian syndrome. Zebrafish (Danio rerio) lacks Müllerian ducts and the Amh receptor gene amhr2 but, curiously, retains amh To discover the roles of Amh in the absence of Müllerian ducts and the ancestral receptor gene, we made amh null alleles in zebrafish. Results showed that normal amh prevents female-biased sex ratios. Adult male amh mutants had enormous testes, half of which contained immature oocytes, demonstrating that Amh regulates male germ cell accumulation and inhibits oocyte development or survival. Mutant males formed sperm ducts and some produced a few offspring. Young female mutants laid a few fertile eggs, so they also had functional sex ducts. Older amh mutants accumulated nonvitellogenic follicles in exceedingly large but sterile ovaries, showing that Amh helps control ovarian follicle maturation and proliferation. RNA-sequencing data partitioned juveniles at 21 days postfertilization (dpf) into two groups that each contained mutant and wild-type fish. Group21-1 upregulated ovary genes compared to Group21-2, which were likely developing as males. By 35 dpf, transcriptomes distinguished males from females and, within each sex, mutants from wild types. In adult mutants, ovaries greatly underexpressed granulosa and theca genes, and testes underexpressed Leydig cell genes. These results show that ancestral Amh functions included development of the gonadal soma in ovaries and testes and regulation of gamete proliferation and maturation. A major gap in our understanding is the identity of the gene encoding a zebrafish Amh receptor; we show here that the loss of amhr2 is associated with the breakpoint of a chromosome rearrangement shared among cyprinid fishes.


Assuntos
Hormônio Antimülleriano/genética , Genitália Feminina/crescimento & desenvolvimento , Processos de Determinação Sexual , Peixe-Zebra/genética , Animais , Feminino , Gônadas/crescimento & desenvolvimento , Ductos Paramesonéfricos/crescimento & desenvolvimento , Folículo Ovariano/crescimento & desenvolvimento , Ovário/crescimento & desenvolvimento , Receptores de Peptídeos/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Peixe-Zebra/crescimento & desenvolvimento
20.
Genetics ; 213(2): 555-566, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31444245

RESUMO

In larval zebrafish, melanocyte stem cells (MSCs) are quiescent, but can be recruited to regenerate the larval pigment pattern following melanocyte ablation. Through pharmacological experiments, we found that inhibition of γ-aminobutyric acid (GABA)-A receptor function, specifically the GABA-A ρ subtype, induces excessive melanocyte production in larval zebrafish. Conversely, pharmacological activation of GABA-A inhibited melanocyte regeneration. We used clustered regularly interspaced short palindromic repeats/Cas9 to generate two mutant alleles of gabrr1, a subtype of GABA-A receptors. Both alleles exhibited robust melanocyte overproduction, while conditional overexpression of gabrr1 inhibited larval melanocyte regeneration. Our data suggest that gabrr1 signaling is necessary to maintain MSC quiescence and sufficient to reduce, but not eliminate, melanocyte regeneration in larval zebrafish.


Assuntos
Larva/genética , Melanócitos/metabolismo , Receptores de GABA-A/genética , Peixe-Zebra/genética , Animais , Diferenciação Celular/genética , Divisão Celular/genética , Larva/crescimento & desenvolvimento , Pigmentação/genética , Regeneração/genética , Transdução de Sinais/genética , Células-Tronco/metabolismo , Peixe-Zebra/crescimento & desenvolvimento , Ácido gama-Aminobutírico/genética
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