Tesi sul tema "Danio rerio – Larves"
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Yedji, Rodrigue. "Perturbateurs endocriniens de type phtalate et poisson zèbre Danio rerio : approche chémoprotéomique pour l'identification des cibles et recherche de signatures d'exposition". Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0106.
Phthalate esters are a family of synthetic compounds widely used as plasticisers. They are used in a number of plastic products such as packaging, toys, cosmetics, plastic roofing system and furniture decoration materials. Phthalates are not covalently bonded to the polymer matrix and are therefore easily released into the environment, resulting in animal and human exposure. In the absence of non-toxic substitutes, phthalate compounds are still widely used in industry, despite the classification of some of them by the European Chemicals Agency (ECHA) as suspected toxic substances and as endocrine disruptors. In addition, they are carcinogenic and teratogenic. The deleterious effect of phthalate esters on organisms is established, but the multiple nature of the effects observed shows that the mechanisms of action of phthalates are only partially elucidated. We used two targeted proteomics approaches to shed light on the mechanisms of action of phthalate esters. Dibutyl phthalate (DBP) was used as a model phthalate and zebrafish (D. rerio) as a model organism. Using the first targeted proteomics approach, affinity-based protein profiling (AfBPP), the functional disruption of proteins by DBP with photoaffinity probes from aryl azide synthesis was demonstrated. Optimisation of the binding conditions for diazirine probes (Diazirine 2) should provide us with a probe that can be used to identify DBP protein targets in the zebrafish proteome. The second approach, activity-based protein profiling (ABPP), used a reactive probe specific for serine hydrolases (SHs) to map active SHs in the zebrafish proteome for the first time. The identification of deregulated SHs in the presence of DBP in zebrafish larvae was also reported in this study. Overall, our results indicate that targeted proteomics approaches such as ABPP or AfBPP can be an asset for understanding xenobiotic-related mechanisms of action in ecotoxicology
Herpin, Amaury. "Caractérisation structurale et fonctionnelle de récepteurs de la superfamille des TGF-ß chez l'huître creuse Crassostrea gigas : implications évolutives". Caen, 2003. http://www.theses.fr/2003CAEN2046.
Reis, Silênio Souza. "Avaliação do desenvolvimento de embriões e larvas de zebrafish (Danio rerio) expostos ao laser de baixa potência". Universidade Federal de Goiás, 2018. http://repositorio.bc.ufg.br/tede/handle/tede/8986.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The low-power LASER is a technology used in the area of health as adjuvant therapy for various diseases. The use of conservative therapies as adjuncts to drug therapy, aim to potentiate therapeutic responses. There are currently some contraindications for the use of LASER in treatments of human patients with open wounds, tumor region and gravid uterus. Thus, zebrafish (D. rerio) is a consolidated organism as an experimental model in the biological, biomedical and environmental areas. The objective of the present work is to evaluate the development of embryos and larvae of zebrafish (D. rerio) exposed to low-power LASER. The LASER III flash with transverse beam output 0,028 cm2, power 100 mW, creep 35, 70 and 140 J / cm2, total energy of 1, 2 and 4 J (Joules), InGaAlP active medium, was used. The data were evaluated according to the normality behavior of Lilliefors using Fisher's exact test, t-test, Mann-Whitney, Kruskal-Wallis (post hoc-Dunn) and Linear Regression by the ORIGIN 7.0 program. The cumulative mortality rate and hatching in embryos (D. rerio) exposed to the LASER in the red spectrum 660 nm and infrared 830 nm 1, 2 and 4 J from 24 - 24 h to 96 hpf was not statistically significant in relation to the wavelength in energy doses in Joules (p ˃ 0,05), infrared laser 830 nm 4J, did not interfere in the development of embryos and larvae (D. rerio), when exposed from 24 - 24 h for a period of 216 hpf. The cumulative mortality rate in the control group was 23 % higher than in the LASER group and the hatching rate in the LASER group was statistically significant (p ˂ 0,05). The cumulative mortality rate in embryos and larvae (D. rerio) when exposed intensively to LASER was statistically significant, as was the hatching rate (p ˂ 0,05) for 96 hpf. There were no statistically significant differences for larval length between the control group compared to the LASER group 24 - 24 h and intensive LASER (p ˃ 0,05). The rate of heart rate in the LASER group 24 - 24 h was statistically significant in relation to the control group and the intensive LASER group (p ˂ 0,05). The rate of spontaneous movements was statistically significant when compared to the control group and the intensive LASER group (p ˂ 0,05). The rate of edema in the control group was statistically significant in relation to the LASER group 24 - 24 h for 96 hpf (p ˂ 0,05). The rate of edema in the intensive LASER group was not statistically significant; however, as in the LASER group 24 - 24 h, the edema in the control group was higher than in the LASER group. The scarcity of theoretical reference on this theme reinforces the pioneering of this work carried out in vivo. The results of this study highlight the importance of the use of embryos and larvae (D. rerio) as a model system in biological, environmental and biomedical research. Data analysis suggests that contraindications for low-power LASER irradiation in patients during the gestational period should be reviewed.
O LASER de baixa potência é uma tecnologia utilizada na área da saúde como terapia coadjuvante a diversas doenças. A utilização de terapias conservadoras como coadjuvantes a terapia medicamentosa, visam potencializar as repostas terapêuticas. Atualmente há algumas contraindicações para utilização do LASER em tratamentos de pacientes humanos com feridas abertas, região tumoral e útero gravídico. Sendo assim, o zebrafish é um organismo consolidado como modelo experimental nas áreas biológica, biomédica e ambiental. O objetivo do presente trabalho é avaliar o desenvolvimento de embriões e larvas do zebrafish (D. rerio) expostos ao LASER de baixa potência. Utilizou-se o flash LASERIII com saída transversa do feixe 0,028 cm2, potência 100 mW, fluência 35, 70 e 140 J/cm2, energia total de 1, 2 e 4 J(Joules), meio ativo InGaAlP. Os dados foram avaliados segundo o comportamento de normalidade Lilliefors através dos testes Exato de Fisher, teste t, Mann-Whitney, Kruskal-Wallis (post hoc-Dunn) e Regressão Linear pelo programa ORIGIN 7.0. A taxa de mortalidade acumulativa e eclosão em embriões (D. rerio) expostos ao LASER no espectro vermelho 660 nm e infravermelho 830 nm 1, 2 e 4 J de 24 - 24 h para 96 hpf não foi estatisticamente significativas em relação ao comprimento de onda em doses de energia em Joules (p ˃ 0,05), O LASER infravermelho 830 nm 4J, não interferiu no desenvolvimento de embriões e larvas (D. rerio), quando expostos de 24 - 24 h por um período de 216 hpf. A taxa de mortalidade acumulativa no grupo controle foi 23 % maior que no grupo LASER e a taxa de eclosão no grupo LASER foi estatisticamente significativa (p ˂ 0,05). A taxa de mortalidade acumulativa em embriões e larvas (D. rerio) quando expostos de forma intensiva ao LASER, foi estatisticamente significativa, assim como a taxa de eclosão (p ˂ 0,05) para 96 hpf. Não houve diferenças estatisticamente significativas para comprimento larval entre o grupo controle em relação ao grupo LASER 24 - 24 h e LASER intensivo (p ˃ 0,05). A taxa de batimentos cardíacos no grupo LASER 24 - 24 h foi estatisticamente significativo em relação ao grupo controle e ao grupo LASER intensivo (p ˂ 0,05). A taxa de movimentos espontâneos foi estatisticamente significativa, quando comparada ao grupo controle e ao grupo LASER intensivo (p ˂ 0,05). A taxa de edema no grupo controle foi estatisticamente significativa em relação ao grupo LASER 24 - 24 h para 96 hpf (p ˂ 0,05). A taxa de edema no grupo LASER intensivo não foi estatisticamente significativa, no entanto, assim como no grupo LASER 24 - 24 h, o edema no grupo controle foi maior que no grupo LASER. A escassez de referencial teórico sobre essa temática reforça o pioneirismo desse trabalho realizado in vivo. Os resultados desse estudo ressaltam a importância da utilização de embriões e larvas (D. rerio) como Sistema - modelo em pesquisas biológicas, ambientais e biomédicas. As análises dos dados sugerem que as contraindicações para irradiação com o LASER de baixa potência em pacientes durante o período gestacional sejam revistas.
Fenero, Camila Ideli Morales. "Estudo do modelo de inflamação intestinal induzida por TNBS em larvas de Zebrafish (Danio rerio)". Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/42/42133/tde-09122015-123622/.
Inflammatory bowel diseases are characterized by a dysregulation in immune response against microbiota. The zebrafish has emerged as a new model for the study of inflammatory diseases. Short chain fatty acids (SCFAs) are products of the intestinal microflora, which have anti-inflammatory roles and appear as a possible therapy against inflammatory diseases. The implementation of intestinal inflammation model induced by trinitrobencenesulfonic acid (TNBS) in zebrafish larvae, increased mortality in a dose-dependent manner. Was observe dilatation lumen and straightening of the intestinal villi. No changes were detected in the production of mucus or in the number of goblet cells but had a slight increase in apoptosis and decreased proliferation in exposed to TNBS. Also has, increased cytokines and infiltrating myeloid cells, and dysbiosis of the microbiota. Treatment with SCFAs generate high mortality above 10 mM concentrations, but there anti-inflammatory action to this same concentration.
Soares, J?ssica Cavalheiro. "Efeitos neurot?xicos da exposi??o ao ?xido de grafeno em larvas de zebrafish (Danio rerio)". Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2017. http://tede2.pucrs.br/tede2/handle/tede/7519.
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Recent studies have shown several applications of graphene oxide (GO) in neurology in the imaging area as a contrast agent for diagnostic purposes, for drug delivery of anticarcinogenic drugs, proteins and peptides and in the field of tissue engineering for applications in the regeneration of nervous lesions. Advances in GO applications research in neurology require addressing its potential toxic mechanisms of action. Zebrafish (Danio rerio) has been widely used in neurotoxicological trials due to the homology of biochemical processes and neural structures with vertebrates. To investigate the potential neurotoxic effects of GO exposure in different concentrations at development period, we evaluated in vivo parameters for initial toxicological screening. We found that GO did not induce changes in survival, hatching and spontaneous movement. However, an increase in heart rate at 48 hpf was found and a reduction in body length without altering the ocular area at 5 dpf. Additionally, molecular gene expression analyses of nervous system-related proteins were performed, showing synapsin IIa expression is increased and dopamine transporter (dat) gene expression is reduced, suggesting a potential compensatory mechanism. The evaluation of the locomotion behavior of animals exposed at GO showed an increase in the absolute turn angle. Based on these initial parameters, we performed biochemical analyzes to determination of the enzyme acetylcholinesterase (AChE) activity and dopamine levels. The exposure at GO did not change AChE activity and decreased dopamine levels. Additionally, the gene expression of B cell lymphoma 2 (bcl2) gene and caspase 3 (casp3) gene were evaluated for the group of larvae exposed to GO, demonstrating an increase of bcl2 and unchanged casp3 expression, suggesting no apoptosis involvement. The tissue and cellular structure of zebrafish larvae brain exposed at GO was evaluated by transmission electron microscopy (TEM) and cell dead by autophagosome formation with loss of cellular architecture was observed most likely due to exposure to the nanomaterial. Further studies are necessary to the complete understanding of the neurological changes observed in zebrafish by exposure to GO and the mechanisms involved in this process, are necessary.
Estudos recentes t?m mostrado diversas aplica??es do ?xido de grafeno (GO) como agente de contraste para fins de diagn?stico, para o endere?amento de drogas (do ingl?s drug delivery) de f?rmacos anticarcinog?nicos, prote?nas e pept?deos e na ?rea de engenharia tecidual para aplica??es na regenera??o de les?es nervosas. O avan?o em pesquisas relacionadas a aplica??es do GO em neurologia exige a investiga??o dos mecanismos de a??o potencialmente t?xicos desencadeados pela exposi??o ao nanomaterial. O zebrafish (Danio rerio) tem sido amplamente utilizado em ensaios neurotoxicol?gicos devido ? homologia de processos bioqu?micos e estruturas neurais com outros vertebrados, vis?veis desde o in?cio de seu desenvolvimento externo. Para investigar os efeitos neurot?xicos da exposi??o a diferentes concentra??es do GO no per?odo de desenvolvimento, foram avaliados diversos par?metros in vivo para avalia??o toxicol?gica preliminar. Foi verificado que o GO n?o induziu altera??es na sobreviv?ncia, eclos?o e movimentos espont?neos. Contudo, o aumento dos batimentos card?acos em 48 hpf foi constatado e redu??o do tamanho do eixo axial, sem altera??o na ?rea ocular em 5 dpf. Adicionalmente, an?lises moleculares da express?o de genes espec?ficos para prote?nas do sistema nervoso foram realizadas mostrando que o GO aumenta a express?o de sinapsina IIa e reduz a express?o do transportador de dopamina (dat), sugerindo um prov?vel mecanismo compensat?rio. A avalia??o da locomo??o dos animais expostos ao GO mostra o aumento do ?ngulo absoluto de virada. Com base nestes par?metros iniciais, foram realizadas an?lises bioqu?micas para a determina??o da atividade da enzima acetilcolinesterase (AChE) e dosagem dos n?veis de dopamina. A exposi??o ao GO n?o alterou a atividade da AChE e reduziu os n?veis de dopamina. Adicionalmente, a express?o do gene de linfoma de c?lulas B2 (do ingl?s B cell lymphoma 2 (bcl2) ) e do gene que codifica para caspase 3 (casp3) foram avaliadas para o grupo de larvas expostas ao GO onde foi mostrado aumento da express?o de bcl2, enquanto que a express?o de casp3 permaneceu inalterada, sugerindo que o GO parece n?o induzir mecanismo de apoptose. A estrutura tecidual e celular do c?rebro de larvas de zebrafish expostas ao GO foi avaliada por microscopia eletr?nica de transmiss?o (TEM) onde morte celular por necrose com perda da arquitetura celular foi constatada. Estudos adicionais para o completo entendimento das altera??es neurol?gicas observadas pela exposi??o ao GO e dos mecanismos envolvidos nesse processo s?o necess?rios.
SILVA, Lívia Laís de Santana. "Avaliação da toxicidade de extrato e lectina de sementes de Moringa oleifera (WsMol) sobre larvas de Danio rerio (peixe paulistinha)". Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/25860.
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CAPES
A WSMoL (do inglês water-soluble Moringa oleifera lectin) é uma lectina (proteína que reconhece carboidratos) proveniente das sementes da Moringa oleifera, as quais são utilizadas no tratamento de água. Algumas espécies de insetos podem atuar como vetores de doenças ou pragas agrícolas. O mosquito Aedes aegypti é o vetor da dengue e sabe-se que o extrato de sementes de M. oleifera e WSMoL são tóxicos para as larvas deste inseto. O extrato de sementes e WSMoL apresentaram uma concentração letal a 50% das larvas após 24 horas de exposição (CL₅₀) igual a 0,27 mg/mL e 0,197 mg/mL, respectivamente. Entretanto, para uma adequada utilização desse inseticida natural se faz necessário a realização de testes ecotoxicológicos a fim de avaliar os possíveis efeitos causados em organismos aquáticos não-alvo. Neste trabalho, foi avaliada a toxicidade de extrato de semente e WSMoL para larvas de Danio rerio, espécie de peixe muito utilizada na Ecotoxicologia devido à facilidade de observação de seu comportamento e desenvolvimento e serem sensíveis na fase larval. As larvas de D. rerio foram expostas a diferentes concentrações do extrato de sementes ou WSMoL por 168 horas (7 dias),tendo sido avaliados efeitos letais por meio da determinação da taxa de mortalidade. Além disso, efeitos sub-letais comportamentais e bioquímicos sobre a velocidade natatória das larvas e atividade da acetilcolinesterase, respectivamente,também foram avaliados. Foi observado um efeito dose dependente na taxa de mortalidade de D. rerio tanto para o extrato quanto para a lectina purificada. Após 24 horas, os valores de CL₅₀/₂₄h foram 0,365 e 0,21 mg/mL para extrato e WSMoL, respectivamente. Esses resultados mostram que a susceptibilidade das larvas de D. rerio a WSMoL foi similar a das larvas de A. aegypti (6% de diferença nos valores de LC₅₀/₂₄h) enquanto extrato é aproximadamente 34% mais potente para as larvas do mosquito. Após 96 horas, os valores de CL₅₀/₂₄h para extrato e WSMoL foram 0,031 e 0,135 mg/mL, respectivamente. Com relação à velocidade natatória dos indivíduos expostos ao extrato, houve um aumento significativo (p < 0,05) após incubação nas concentrações 0,03 e 0,27 mg/mL e uma diminuição para larvas incubadas com 0,81 mg/mL por esse mesmo período. Para incubação por 168 h, a velocidade foi maior que no grupo controle para os tratamentos a 0,27 e 0,81 mg/mL. Nos ensaios com WSMoL, a média da velocidade de natação de larvas expostas à lectina por 72 h foi significativamente (p < 0,05) menor que no controle nos tratamentos com 0,1 e 0,2 mg/mL. Para 168 h, a velocidade foi também menor que no controle no tratamento a 0,1 mg/mL enquanto para as concentrações de 0,02 e 0,05 mg/mL foi similar (p > 0,05) ao controle.Larvas expostas por 168 h ao extrato aquoso na concentração 0,81 mg/mL e a WSMoL na concentração de 0,1 mg/mL apresentaram uma redução significativa na atividade da acetilcolinesterase. Levando em consideração os resultados obtidos, esses inseticidas naturais devem ser usados cuidadosamente, uma vez que as concentrações necessárias para o controle de A. aegyptiforam podem também causar efeitos tóxicos letais e sub-letais para organismos não-alvo como o peixe D. rerio. Recomenda-se o uso em recipientes de armazenamento de água, e não em ecossistemas aquáticos como lagoas e lagos.
Some insect species can act as vectors of diseases or as agricultural pests. The WSMoL (water soluble Moringa oleifera lectin) is a lectin (protein that recognizes carbohydrate) derived from the seeds of Moringa oleifera, which are used in water treatment. The mosquito Aedes aegypti is the vector of dengue and it is known that M. oleifera seed extract and WSMoL are toxic to larvae of this insect. The seed extract and WSMoL showed a lethal concentration to 50% of the larvae after 24 hours of exposure (LC₅₀) equal to 0.27 mg/mL and 0.197 mg/mL, respectively. However, for proper use of these natural insecticides, it is necessary to carry out ecotoxicological tests in order to assess the possible effects on non-target aquatic organisms. In this work, the toxicity of seed extract and WSMoL to zebrafish (Danio rerio) larvae was evaluated. Danio rerio is a fish species very used in Ecotoxicology due to the ease of observation of its behavior and development and for being sensitive in the larval stage. D. rerio larvae were exposed to different concentrations of the seed extract or WSMoL for 168 h (7 days) and the lethal effects were assessed by determining the mortality rate. Additionally, behavioral and biochemical sublethal effects on larval swimming velocity and acetylcholinesterase activity, respectively, were also evaluated. It was observed a dose dependence effect on D. rerio mortality rate for both the extract and the purified lectin. After 24 h, the values of LC₅₀/₂₄h were 0.365 and 0.21 mg/mL to extract and WSMoL, respectively. These results show that the D. rerio larvae susceptibility to the WSMoL was similar to A. aegypti larvae (6% difference in LC₅₀/₂₄h values) while extract was about 34% more potent against mosquito larvae. After 96 h, the values of LC₅₀/₂₄h for extract and WSMoL were 0.031 and 0.135 mg/mL, respectively. Concerning the swimming velocity of individuals exposed to the extract there was a significant increase (p <0.05) after incubation for 72 h at 0.03 and 0.27 mg/mL and a decrease for larvae incubated at 0.81 mg/mL for this same period. For 168 h incubation, the velocity was higher than control group for treatments at 0.27 and 0.81 mg/mL. In tests with WSMoL, the average swimming velocity of larvae exposed to the lectin for 72 h was significantly (p <0.05) lower than the control on treatments with 0.1 and 0.2 mg/mL. For 168 h, the velocity was also lower than the control on treatment with 0.1 mg/mL, and with concentrations of 0.02 and 0.05 mg/mL the values were similar (p>0.05) to the control. Larvae exposed for 168 h to the aqueous extract at a concentration of 0.81 mg/mL and WSMoL at 0.1 mg/mL showed a significant reduction in the activity of acetylcholinesterase. Considering the results, these natural insecticides must be used carefully used since the concentrations necessary for the control of A. aegypti also can cause lethal toxic effects and sub-lethal to non-target organisms such as D. rerio fish. It is not recommended to use these natural insecticides in aquatic ecosystems such as ponds and lakes, but in water storage containers.
Gore, Matthew R. "Influence of parental swimming stamina on the cardiac and metabolic performance of larval zebrafish (Danio rerio)". Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc3669/.
Nogueira, Ana Filipa Ferreira. "Developmental, behavioral, biochemical and epigenetic effect of pharmaceuticals in larvae and embryos of Danio rerio". Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22024.
The scientific community has been concerned for several years about the presence of pharmaceuticals in the wild, since these compounds may have deleterious or unpredictable effects on living organisms. The scientific knowledge on the fate and effect of drug residues in the environment has evolved considerably in recent years, revealing that drug residues do indeed pose a threat to the aquatic ecosystem. Two examples of widely used pharmaceuticals that are present in the environment are paracetamol (acetaminophen) and ciprofloxacin, Paracetamol is a drug with analgesic properties, used for the temporary relief of mild to moderate pain associated with common colds, and in the reduction of fever. Ciprofloxacin is an antibiotic from the chemical class of the fluoroquinolones which presents a broad antibacterial spectrum. Firstly we decided the range of concentrations for each drug. In the case of paracetamol, the tested concentrations were 0.005 mg/L, 0.025 mg/L, 0.125 mg/L, 0.625 mg/L, and 3.125 mg/L, plus a control treatment with water from the facility system. And for ciprofloxacin, the tested concentrations were 0.005 μg/L, 0.013 μg/L, 0.031 μg/L, 0.078 μg/L, 0.195 μg/L, and 0.488 μg/L. These concentrations were chosen as for their environmental relevance since they are close to the real concentrations of these pharmaceuticals found in surface waters and effluents. This work aims to characterize the effects of both drugs in zebrafish embryos and larvae, not only in developmental and behaviour parameters, but also using a biomarker-based approach, namely by quantifying the activities of catalase (CAT), glutathione-S-transferase (GST’s), cholinesterases (ChE’s), glutathione peroxidase (GPx), and determining the TBARS level. Exposure to paracetamol caused an increase in the percentage of organisms with morphological deformations, but no morphological deformations were observed in organisms exposed to ciprofloxacin. Concerning larvae behavioural tests, significant differences were observed for larvae exposed to paracetamol but not for larvae exposed to ciprofloxacin. In the biomarker determination, both drugs caused a statistically significant increase in ChE activity; in CAT only ciprofloxacin caused a significant difference, a decrease in its activity. Paracetamol induced an increase in activity for total GPx and in GST’s. The TBARS levels significantly increased in the exposure to paracetamol, but they significantly decreased in the exposure to ciprofloxacin. In this work, we also prepared an immunohistochemical detection of global methylation, which allowed to observe that, in embryos, the highest concentration of paracetamol caused a slight increase in the intensity of the 5- mdC signal, which can be translated into a slight increase in the DNA methylation. On the other hand, the embryos exposed to ciprofloxacin did not appear to have any difference from control. The comparison of the here-obtained results for the two different drugs allows observing that zebrafish larvae were more sensitive to the exposure to paracetamol, being the most sensitive methodology the biomarker determination. We can also conclude that oxidative stress occurred as a consequence of the exposure to both pharmaceuticals, being more evident in the case of paracetamol. We also showed that the oxidative stress created by the two pharmaceuticals may be the cause of all the other observations.
A presença de produtos farmacêuticos na natureza é uma questão emergente para a comunidade científica uma vez que estes compostos podem ter efeitos deletérios ou imprevisíveis sobre os organismos vivos. O estudo dos efeitos dos resíduos de medicamentos no ambiente evoluiu consideravelmente nos últimos anos, revelando que estes resíduos são uma ameaça para o ecossistema aquático. Dois exemplos de produtos farmacêuticos amplamente utilizados por humanos e presentes no meio ambiente são o paracetamol (acetaminofeno) e a ciprofloxacina. O paracetamol é um medicamento com propriedades analgésicas, utilizado para o alívio temporário da dor leve a moderada associada a gripes comuns, e na redução da febre. A ciprofloxacina é um antibiótico da classe química das fluoroquinolonas que apresenta um amplo espectro antibacteriano. Este trabalho tem como objetivo utilizar larvas de peixe-zebra e caracterizar os efeitos de ambos os medicamentos, não apenas nos parâmetros de desenvolvimento e comportamento, mas também usando com uma abordagem baseada em biomarcadores, nomeadamente quantificando as atividades de catalase (CAT), glutationa-S-transferase (GST), colinesterases (ChE's), glutationa peroxidase (GPx) e determinação do nível TBARS, bem como uma abordagem epigenética. Neste trabalho, também avaliamos por técnicas histoquímicas a metilação global do ADN. No caso do paracetamol, as concentrações testadas foram 0.005 mg/L, 0.025 mg/L, 0.125 mg/L, 0.625 mg/L, e 3.125 mg/L, juntamente com o controlo que apenas continha água do sistema. Para a ciprofloxacina, as concentrações testadas foram 0.005 μg/L, 0.013 μg/L, 0.031 μg/L, 0.078 μg/L, 0.195 μg/L, e 0.488 μg/L. Estas concentrações foram escolhidas pela sua relevância ambiental, uma vez que são muito próximas às concentrações destes fármacos no ambiente. A exposição ao paracetamol causou um aumento na percentagem de organismos com deformações morfológicas, mas não foram observadas deformações morfológicas em organismos expostos à ciprofloxacina. Quanto aos testes comportamentais com larvas de peixe-zebra, observaram-se diferenças significativas nas larvas expostas ao paracetamol, que demonstraram uma maior distância de natação, mas o mesmo efeito não foi observado para as larvas expostas à ciprofloxacina. Os dados obtidos para os diferentes biomarcadores demonstraram que ambos os fármacos causaram um aumento estatisticamente significativo na atividade de ChE. Na actividade da CAT, apenas a ciprofloxacina causou diferença significativa, mais propriamente uma descida na atividade da CAT. O paracetamol induziu um aumento na atividade da GPx total e das GSTs. Os níveis de TBARS aumentaram significativamente após exposição ao paracetamol, mas diminuíram significativamente em organismos expostos à ciprofloxacina. Os dados relativos à quantificação da metilação global do ADN permitiram observar que, em embriões, a maior concentração de paracetamol causou um ligeiro aumento na intensidade do sinal do marcador de metilação de ADN (5- mdC,) quando observado por miscroscopia de confocal. Por outro lado, os embriões expostos à ciprofloxacina não aparentavam ter qualquer diferença no perfil deste marcador de epigenética comparativamente ao controlo. A comparação dos resultados aqui obtidos para os dois fármacos diferentes permite observar que as larvas de peixe zebra eram mais sensíveis à exposição ao paracetamol, sendo a metodologia mais sensível a determinação do biomarcador. Também podemos concluir que o estresse oxidativo ocorreu como conseqüência da exposição a ambos os produtos farmacêuticos, sendo mais evidente no caso do paracetamol. Também mostramos que o estresse oxidativo criado pelos dois produtos farmacêuticos pode ser a causa de todas as outras observações.
Perrichon, Prescilla. "Développement de tests embryonnaires prédictifs d’effets toxiques précoces et tardifs pour des molécules hydrophobes". Thesis, La Rochelle, 2014. http://www.theses.fr/2014LAROS040/document.
PAHs are ubiquitous widespread contaminants which emissions are overgrowing with increasing anthropogenic activities. These semi-persistent chemicals are threatening organisms in the environment. Ecosystems health and resilience are essential to life and societal functioning. Impact assessment of these chemicals is a real requirement for society thereby establishing the european legislative (DCE, Water Framework Directive) and regulations (REACH, Registration, Evaluation, Authorisation and Restriction of Chemicals) for better (eco)toxicological risk management. In this context, many bioassays have been developed to assess environmental quality, the toxicity of chemicals (including mixture) on organisms and its underlying mechanisms. This study aimed to identify (eco)toxicological risks in the context of fish embryo-larval assay, using a relevant and well-known model : the zebrafish Danio rerio. Two complementary approaches (chemical and biological) were used to assess transfer, fate and toxicity of PAHs. Induced-responses were evaluated at different levels of biological organization, from molecular (oxidative stress, DNA damage, EROD) to physiological (cardiac activity), behavioral (PhotoMotor Response) and morphological levels. Among the three exposure routes tested, the sediment contact exposure was not suitable for PAHs toxicity assessment. In contrast, exposures to water-accommodated fractions (WAF) of petroleum products represented a more reproducible, sensitive and integrative approach for testing multiscale toxic effects. Following these experiments, the observation scope of induced effects should be broadened beyond the standard duration recommended by the Organization for Economic Cooperation and Development in order not to underestimate the acute effect of the tested-compounds. Furthermore, our multigenerational study showed physiological and behavioral disturbances on the first generation of offspring providing from parents exposed to contaminated-food with three aromatic extracts pyrolytic and petrogenic origin (heavy and light). Although the contamination transfer of PAHs has not been revealed, the observed alterations (probably due to a transfer through genetic and epigenetic modifications) in the early stages of zebrafish could have adverse effects on survival and recruitment populations. Multigenerational studies prove to be an integrated approach for the toxicity assessment of chemicals and strengthen the predictive effects. These ecotoxicological studies should be widely undertaken to evaluate the potential for exposed-population to maintain in the future time
Delomas, Thomas Allin. "Sex determination and interspecies hybridization in zebrafish Danio rerio and pearl danio D. albolineatus". The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1522574215273393.
Strmac, Marija. "Ökotoxikologische Untersuchung und Bewertung verschiedener Kompartimente in kleinen Fliessgewässern mit Hilfe von Zellkulturen sowie Embryonen und Larven des Zebrabärblings (Danio rerio)". [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=961834374.
Cruz, Fernanda Fernandes. "Efeito da cafe?na e dos receptores de adenosina na inflama??o induzida por cobre em larvas de zebrafish (Danio rerio)". Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2016. http://tede2.pucrs.br/tede2/handle/tede/6671.
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Zebrafish (Danio rerio) is a bony fish originated in Pakistan and India with anatomical and physiological characteristics and its genome is homologous to the more developed organisms, which suggests that many genes involved in human diseases can be coincident to the zebrafish genome. Copper is a heavy metal involved in formation of ROS, responsible for the lipid peroxidation in the membrane, direct protein oxidation and cleavage of DNA and RNA molecules. Purines (ATP, ADP and adenosine) and pyrimidine (UTP and UDP) can act as extracellular signaling molecules, exerting different physiological effects when binding to purninergic receptors. There are two families of purinergic receptors: adenosine receptors or P1 (P1R), and P2 receptor (P2R). The P1R are a family of G protein-coupled receptors and are divided inA1, A2A, A2B, and A3 subtypes. Adenosine is the major ligand for P1R, and is involved in important physiological functions such as modulation of neurotransmitter release, synaptic plasticity, neuroprotection to ischemic events, hypoxia and oxidative stress. Studies suggest that drugs that interfere in adenosine signaling may weaken the protective mechanisms and lead to an exacerbation of the inflammatory response. Caffeine is the most widely consumed psychoactive substance in the world and is a nonselective antagonist of adenosine receptors. This study aimed to evaluate the effect of caffeine in copper-induced inflammation in zebrafish larvae. The animals were treated with copper at a concentration of 10 ?M and three different concentrations of caffeine (100 ?M, 500 ?M e 1 mM) to determine the survival rate and to define timepoints and concentrations for the following experiments. It was observed that high concentrations of caffeine combined with copper caused a significant decrease of larvae survival after 24 h of treatment. For the following experiments, we chose 4 and 24 h of exposure, 500 ?M caffeine and 10 ?M copper concentrations. After 4 h of treatment, caffeine was able to change the behavior parameters. It was shown that both copper and caffeine might have an anxiogenic effect on zebrafish larvae after 24 h exposure. For the evaluation of inflammatory profile, inflammation markers PGE2, COX-2, TNF, IL-6 and IL-10 were chosen. In 4 hours of exposure, PGE2 levels are increased in groups treated with copper and caffeine. Caffeine showed an additive effect on the PGE2 release. The gene expression of TNF, as well as COX-2 was increased by copper treatment, however, in treatments with caffeine there was a reduction of COX-2 gene expression. In 24 h of treatment, caffeine induced an increase in COX-2, TNF, IL-6 and decrease IL-10 expression. The treatment with copper and caffeine combined increased the expression of the four adenosine receptor subtypes, especially after 4 h of exposure. This may be a result of receptors blockade by caffeine, or a physiological response to inflammation induced by copper, since adenosine, in general, exerts an anti-inflammatory effect. Although caffeine markedly decreased animal survival when combined to copper, caffeine did not potentiate the inflammatory and behavioral effects induced by copper. Our results suggest that caffeine alone is able to exert inflammatory and anxiogenic actions in zebrafish larvae at the timepoints and concentrations assessed.
O zebrafish (Danio rerio) ? um peixe ?sseo origin?rio do Paquist?o e da ?ndia com caracter?sticas anat?micas e fisiol?gicas hom?logas aos organismos mais desenvolvidos. Possui o seu genoma mapeado, com homologia ao genoma humano, o que sugere que diversos genes envolvidos em doen?as humanas podem ser coincidentes ao do genoma do zebrafish. O cobre ? um metal pesado que est? envolvido na produ??o de esp?cies reativas de oxig?nio, respons?veis pela peroxida??o de l?pidios nas membranas, oxida??o direta de prote?nas, e clivagem de mol?culas de DNA e RNA. Purinas (ATP, ADP e adenosina) e pirimidinas (UTP e UDP) extracelulares podem atuar como mol?culas sinalizadoras end?genas exercendo diferentes efeitos fisiol?gicos. Para tais ligantes, existem duas fam?lias de receptores purin?rgicos: receptores de adenosina ou P1 (P1R), e receptores P2 (P2R). Os P1R t?m como ligante end?geno a adenosina, e s?o uma fam?lia de receptores metabotr?picos, acoplados ? prote?na G, e se dividem nos subtipos A1, A2A, A2B e A3. A sinaliza??o mediada pela adenosina est? envolvida em importantes fun??es fisiol?gicas, como a modula??o da libera??o de neurotransmissores, plasticidade sin?ptica, neuroprote??o em eventos isqu?micos, hip?xia e estresse oxidativo. Estudos sugerem que subst?ncias que interferem na sinaliza??o adenosin?rgica na hip?xia podem enfraquecer os mecanismos protetores, resultando no aumento da resposta inflamat?ria. A cafe?na (1,3,7 ? trimetilxantina) ? a subst?ncia psicoativa mais consumida no mundo e ? um antagonista n?o seletivo dos receptores de adenosina. Este trabalho teve como objetivo avaliar o efeito da cafe?na na inflama??o induzida por cobre em larvas de zebrafish. Os animais foram tratados com cobre na concentra??o de 10 ?M e com outras 3 concentra??es diferentes de cafe?na (100 ?M, 500 ?M e 1 mM). Foi observado, que altas concentra??es (500 ?M e 1 mM) de cafe?na juntamente com o cobre provocaram um aumento significativo na mortalidade das larvas ao final de 24 horas de tratamento. Para os experimentos seguintes, foram escolhidos os tempos 4 e 24 horas e a concentra??o de 500 ?M de cafe?na e 10 ?M de cobre. Em 4 horas de tratamento, a cafe?na foi capaz de alterar os par?metros de comportamento avaliados. Foi demonstrado que tanto o cobre quanto a cafe?na, podem exercer um efeito ansiog?nico nas larvas de zebrafish ap?s 24 horas. Para a avalia??o do perfil inflamat?rio, foram escolhidos os marcadores de inflama??o PGE2, COX-2, TNF, IL-6 e IL-10. Foi mostrado que em 4 horas de exposi??o h? um aumento dos n?veis de PGE2 nos grupos tratados com cobre e cafe?na, mostrando um efeito aditivo da cafe?na em rela??o ? inflama??o induzida por cobre. A express?o g?nica de TNF, bem como a de COX-2 foi aumentada pelo tratamento com cobre, por?m, nos tratamentos com cafe?na houve uma diminui??o da express?o g?nica de COX-2. Em 24 horas de tratamento, a cafe?na induziu um aumento na express?o de COX-2, TNF, IL-6 e diminui??o de IL-10. Os tratamentos com cobre e cafe?na aumentaram a express?o dos 4 subtipos de receptores de adenosina principalmente ap?s 4 horas de exposi??o. Isso pode ser devido ao bloqueio dos receptores pela cafe?na e por uma medida fisiol?gica de defesa em resposta ? inflama??o induzida pelo cobre, visto que a adenosina, de uma forma geral, exerce um efeito anti-inflamat?rio. Embora a cafe?na tenha induzido uma diminui??o significativa da sobrevida dos animais, quando adicionada ao tratamento com cobre, nos marcadores inflamat?rios e nos par?metros comportamentais estudados, n?o houve um efeito aditivo da cafe?na na inflama??o induzida pelo cobre. Nossos resultados sugerem que a cafe?na por si s? ? capaz de exercer uma a??o inflamat?ria e ansiog?nica em larvas de zebrafish nos tempos e concentra??es estudados.
Gusso, Darlan. "Efeito do Piriproxifeno sobre o desenvolvimento, par?metros comportamentais e end?crinos em larvas e adultos de Peixe-zebra (Danio rerio)". Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2018. http://tede2.pucrs.br/tede2/handle/tede/7950.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Mosquitoes are responsible for the transmission of various pathogens. Over the past three years, the world has witnessed epidemics affecting all age groups, such as dengue fever, yellow fever, chikungunya and zika virus. To control and eliminate Aedes vectors responsible for the transmission of these diseases, it is necessary to use larvicides and insecticides such as pyriproxyfen. Pyriproxyfen is a larvicide used to control mosquitoes, mainly of the genus Aedes. This study evaluated the effects of pyriproxyfen on survival, morphology, behavior, and endocrine parameters at different stages of zebrafish development. We have demonstrated that pyriproxyfen can cause changes in the survival rate, behavior and morphology of exposed larvae, adults exposed at the larval stage, and adult offspring of exposed parents. Larvae exposed to pyriproxyfen for 1-96 hpf (hours post-fertilization) showed a decrease in survival rate, heart rate 3 dpf (days post-fertilization), and body length at 5 and 8 dpf. The distance traveled and the mean velocities of the exposed larvae were reduced in comparison to the vehicle group (1% DMSO). Therefore, pyriproxyfen changes the morphology and behavior of zebrafish in early stages of development and may affect the next generations. However, when the exposed larvae were maintained until the adult stage (6 months), we did not observe differences in locomotor parameters. Parental exposure to pyriproxyfen induced decrease in locomotion of zebrafish adult offspring as well as an anxiolytic-like behavior. We also tested pyriproxyfen exposure for 96 hours in adult zebrafish and the locomotion, anxiety, memory and endocrine parameters were analyzed as well as the gene expression of the glucocorticoid receptor (GR) and corticotropin-releasing factor (CRF). These results showed that there was no significant difference in locomotion, anxiety and endocrine parameters. In addition, there was an impairment of habituation memory in adult zebrafish exposed to pyriproxyfen. Therefore, it is important to control the use of larvicides due to their toxic effects on non-target species. Our findings demonstrated the importance of studies related to the use of larvicides, since they are potential causes of morphological and behavioral alterations in aquatic species, such as zebrafish.
Mosquitos s?o respons?veis pela transmiss?o de v?rios agentes patog?nicos. Nos ?ltimos tr?s anos, o mundo testemunhou epidemias que afetam todas as faixas et?rias, tais como dengue, febre amarela, chikungunya e zika v?rus. Para controlar e eliminar vetores do g?nero Aedes, respons?vel pela transmiss?o destas doen?as, ? necess?rio usar larvicidas e inseticidas como o piriproxifeno. O piriproxifeno ? um larvicida usado para eliminar mosquitos, principalmente do g?nero Aedes. Este estudo avaliou os efeitos do piriproxifeno sobre a sobreviv?ncia, morfologia, comportamento e par?metros end?crinos em diferentes est?gios de desenvolvimento de peixe-zebra. N?s demonstramos que o piriproxifeno pode causar altera??es na taxa de sobreviv?ncia, comportamento e morfologia de larvas expostas, adultos expostos no est?gio larval e descendentes adultos de pais expostos. As larvas expostas ao piriproxifeno durante 1-96 hpf (horas p?s-fertiliza??o) mostraram uma diminui??o na taxa de sobreviv?ncia, frequ?ncia card?aca 3 dpf e comprimento corporal nos 5 e 8 dpf (dias p?s- fertiliza??o). A dist?ncia percorrida e a velocidade m?dia das larvas expostas foram reduzidas em rela??o ao grupo ve?culo (1% de DMSO). Portanto, o piriproxifeno altera a morfologia e o comportamento do peixe-zebra em est?gios iniciais de desenvolvimento e pode afetar as pr?ximas gera??es. No entanto, quando as larvas expostas foram mantidas at? o est?gio adulto (6 meses), n?o observamos diferen?as nos par?metros locomotores. A exposi??o parental ao piriproxifeno induziu uma diminui??o na locomo??o da prole adulta, bem como um comportamento do tipo ansiol?tico. N?s tamb?m avaliamos o efeito da exposi??o ao piriproxifeno em peixe-zebra na fase adulta durante 96 horas sobre a locomo??o, ansiedade, mem?ria e par?metros end?crinos, como express?o g?nica do receptor de glicocorticoide (GR) e fator de libera??o de corticotrofina (CRF). Os resultados demonstraram que n?o houve diferen?a significativa na locomo??o, ansiedade e par?metros end?crinos. Al?m disso, houve um preju?zo da mem?ria de habitua??o do peixe-zebra adulto exposto ? piriproxifeno. Portanto, ? importante controlar o uso de larvicidas devido aos seus efeitos t?xicos em esp?cies n?o-alvo. Nossos achados demonstram a import?ncia de estudos relacionados com a utiliza??o de larvicidas, uma vez que s?o potenciais causadores de altera??es morfol?gicas e comportamentais em esp?cies aqu?ticas, como o peixe-zebra.
Ho, Dao H. "Morphological and physiological developmental consequences of parental effects in the chicken embryo (Gallus gallus domesticus) and the zebrafish larva (Danio rerio)". Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc9086/.
Jouary, Adrien. "Comportement moteur induit visuellement et spontané chez la larve du poisson zèbre". Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066605/document.
Behavior is often conceived as resulting from a stimulus-response association. Under this paradigm, understanding the nervous system is reduced to finding the relation between a sensory input and a motor output. Yet, in naturally behaving animals, motor actions influence sensory perceptions just as much as the other way around. Animals are continuously relying on sensory feedback to adjust motor commands. On the other hand, behavior is not only induced by the sensory environment, but can be generated by the brain's rich internal dynamics. My goal is to understand the sensory-motor dialogue by monitoring large brain regions, yet, with a single-neuron resolution. To tackle this question, I have used zebrafish larva to study visually induced and internally driven motor behaviors. Zebrafish larvae have a small and transparent body. These features enable using large-scale optical methods, such as selective plane illumination microscopy (SPIM), to record brain dynamics. In order to study goal-driven navigation in conditions compatible with imaging, I developed a visual virtual reality system for zebrafish larva. The visual feedback can be chosen to be similar to what the animal experiences in natural conditions. Alternatively, alteration of the visual feedback can be used to study how the brain adapts to perturbations. For this purpose, I first generated a library of free-swimming behaviors from which I learned the relationship between the trajectory of the larva and the shape of its tail. I then use this technique to infer the intended displacements of head-fixed larvae. The visual environment was updated accordingly. In the virtual environment, larvae were capable of maintaining the proper speed and orientation in the presence of whole-field motion and produced fine changes in orientation and position required to capture virtual preys. I demonstrate the sensitivity of larvae to visual feedback by updating the visual world only after the discrete swimming episodes. This feedback perturbation induced a decay in the performance of prey capture behavior, suggesting that larva rely on real-time visual feedback during swimming. Behavior can also be induced by the internal dynamics of the brain. In the absence of salient sensory cues, zebrafish larva spontaneously produces stereotypical tail movements, similar to those produced during goal-driven navigation. After having developed a new method to classify tail movements, I analyzed the sequence of spontaneously generated tail movements. The latter switched between period of quasi-rhythmic activity and long episodes of rest. Moreover, consecutive movements were more similar when executed at short time intervals (~10s). In order to study the mechanisms responsible for the spontaneous decisions to move, I coupled SPIM to tail movement analysis. Using dimensionality reduction, I identified clusters of neurons predicting the direction of spontaneous turn movements but not their timings. This Preliminary result suggests that distinct pathways could be responsible for the timing (when) and the selection (what) of spontaneous actions. Together, the results shed light on the role of feedback and internal dynamics in shaping behaviors and open the avenue for investigating complex sensorimotor process in simple systems
Terras, Fériel. "Développement d’une méthode de mesure et d’analyse du transport intraneuronal dans le cerveau de larve de poissons-zèbre par suivi de nanocristaux non-linéaires en microscopie de second-harmonique : application à l’étude d’anomalies de transport chez des poissons portant une mutation retrouvée dans des neuropathies humaines". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP050.
Molecular transport in neurons plays an essential role in their development and the maintenance of their functions, due in particular to their long branches. The consequences of axonal transport abnormalities have long been associated with Alzheimer's disease, such as the swelling of axons caused by the accumulation of transported organelles. However, there are few tools allowing the detailed long-term study of this transport in culture and even less in vivo.The team in which this work was conducted has developed a method for measuring intraneuronal transport in mouse cultured neurons based on the tracking of endosomes having spontaneously internalized fluorescent nanodiamonds. This technique was able to detect genetic risk factors of neuropsychiatric diseases, proving its high sensitivity.The objective of my thesis was to extend this measurement method to the neuronal circuit of the zebrafish larvae’s brain. For this purpose, I have used nanocrystals (NCs) with non-linear optical response, which can be excited in a tissue transparency window at a wavelength ≈1 µm, and generate a second harmonic signal. We have used the multiphoton microscope of the Emerg'In facility (INRAE, Jouy-en-Josas), which is installed next to a fish farming and has resonant galvanometric scanners and hybrid detectors, which allowed us to maintain a frame rate of 20 fps despite the need to scan the laser beam, unlike in culture studies conducted in wide field.We have developed a new measurement protocol, from the injection of the NC to the extraction of transport parameters from the videos data. To do this, I have optimized and automated the data analysis by developing two programs written in Python: one that automatically reconstructs the trajectories of the NCs as faithfully as possible and the other that segments the trajectories into motion and pause phases in order to extract transport parameters.I have applied these new tools to study, in a transgenic zebrafish model, the functional impact of a mutation present in neuropathies including hereditary spastic paraplegia and peripheral Charcot-Marie-Tooth disease. In patients suffering from one of these diseases, several mutations have been identified in the KIF5A gene coding for the heavy chain of the kinesin 1 molecular motor which ensures anterograde movements (from the cell body to the periphery). We have measured endosome transport in axons of neurons in the brain of transgenic zebrafish larvae bearing a mutation on kif5a, and we observed subtle changes in this transport. More than 500 endosome trajectories (acquired at a depth of ≈100 µm below the surface of the head) were analyzed from 40 larvae.As a control, we also studied endosomal transport in mutants deprived of dynein motors, the only ones to ensure retrograde transport, and observed that bi-directional transport was totally stopped in the mutants.This methodology can be used to screen for functional abnormalities resulting from genetic factors of neurological or neurodegenerative disorders
Barnes, Amber K. "Zebrafish as a Model for Prenatal Alcohol Exposure: An Investigation Into Behavioral and Developmental Effects". University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1354306697.
Cormier, Bettie. "Toxicité des microplastiques chez les poissons, au-delà de simple vecteurs de polluants?" Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0036.
During the last decades, plastics have gained interest from media, public and scientists. Plastics have been categorized as emerging pollutants particularly in the marine environment due to their ubiquity and persistence, particularly microplastics (< 5 mm, MPs). Numerous studies reported the occurrence of MPs in the marine environment (surface water, sediments). However, neither there exist standardized nor harmonized methods to evaluate their potential toxicity and their role as vector of hazardous chemicals into organism. This thesis had three main objectives, (1) the investigation of sorption of chemicals models on MPs, (2) the study of the toxic potential of these sorbed chemicals on zebrafish and (3) the characterization and the study of the toxicity of environmental MPs. The first part of the thesis aimed at the investigation of the sorption processes of three model pollutants - perfluorooctanesulfonic acid (PFOS), benzo[a]pyrene (BaP) and oxybenzone (BP3) - on pristine MPs using different sizes and polymer types. The second part studied the vectorization of the three compounds sorbed on MPs toward zebrafish (Danio rerio) embryos, juveniles and adults through direct or trophic exposures, and their toxicities. The third part investigated the toxicity of environmental samples of MPs from two sandy beaches (Guadeloupe Island, France), using the same procedure as above, as well as the characterization of additives and adsorbed chemicals through a non-target approach. Study of pollutants sorption demonstrated differences in pattern (e.g. kinetics, sorption efficiency), depending on size particles and chemical used. Potential adverse effects of MPs associated with chemicals were investigated in zebrafish embryos using OECD 236 guideline and by using a chronic exposure from larvae or juveniles up to 5-months old adults through trophic exposure. Molecular and individual toxicological endpoints were monitored during exposure. Main findings were the low acute toxicity of MPs on early life stages (embryos and larvae) exposed to particles, organic extracts or leachates. Nevertheless, the ingestion of MPs by juveniles and adults led to a significant long-term toxicity for all tested MPs albeit with different intensity according to the spiked chemicals and to the environmental samples. Deleterious effects included growth alteration, reprotoxicity, behavioral disturbances as well as hyperactivity observed in offspring of exposed fish. In conclusion, the present work revealed that (1) MPs may play a role in the vectorization of pollutants and (2) may induce significant sublethal effects in juveniles of zebrafish chronically fed with pristine MPs or MPs artificially spiked with pollutants. Same conclusions were observed (3) with environmental MPs
Santos, Rui Pedro Peres dos. "O efeito da Varfarina no desenvolvimento esquelético de larvas de peixe zebra (Danio rerio)". Master's thesis, 2009. http://hdl.handle.net/10400.1/11039.
The Vitamin K-dependent (VKD) carboxylase allows the conversation of the glutamyl residues (Glu) to carbolxy glutamic acid (Gla), having an effect on the vitamin K dependente (VKD) proteins, and this go influence the physiology of the homeostasis, apoptosis, signal transduction, growth control, arterial calcification and skeletal development. Matrix Gla protein (MGP) and osteocalcin (Oc or bone Gla Protein- BGP) have the capacity to bind calcium trough the gla domain, something essential for biological activity as inhibitor of calcification (Mgp) and modulator of hydroxyapatite crystals. We used developing larvae of zebrafish (Danio rerío) to evaluate the effects of warfarin in skeletal development. Warfarin is a known anticoagulant, that inhibits the action of vitamin K carboxylation (VKGC), inhibiting the maturation of oc and mgp taking to an incorrect result of their function. For accessing the effects of warfarin we used whole mount double staining with Alcian Blue and Alizarin red revealing a decrease im mineralization. The imunodetection of Oc and Mgp showed an increased accumulation in calcified tissues and quantitative real time PCR showed a upregulation of both oc and mgp as response to warfarin treatment. Warfarin appears to affect the correct calcification in larvae and affect the function of Oc and Mgp.
"Effects of inorganic mercury on developing zebrafish (Danio rerio) larvae". Thesis, 2015. http://hdl.handle.net/10388/ETD-2015-10-2243.
Strmac, Marija [Verfasser]. "Ökotoxikologische Untersuchung und Bewertung verschiedener Kompartimente in kleinen Fließgewässern mit Hilfe von Zellkulturen sowie Embryonen und Larven des Zebrabärblings (Danio rerio) / Marija Strmac". 1999. http://d-nb.info/961834374/34.
Silva, João Pedro Gonçalves Cardeira da. "O efeito da dieta na sobrevivência e no desenvolvimento esquelético e digestivo de larvas e juvenis de peixe-zebra Danio rerio (Hamilton, 1822)". Master's thesis, 2009. http://hdl.handle.net/10400.1/672.
Zebrafish is a freshwater teleost which, due to several biological and genetic characters, has been widely used as a vertebrate model in a variety of research fields, with great potential in molecular biology. As a consequence of the increasing interest in zebrafish, the optimization of its rearing conditions becomes essential, such as the determination of a standardized feeding regime appropriate to this species’. Four different dietary regimes, composed of rotifers Brachionus sp., Artemia nauplii and inert food (Cyclop-eezeTM e BeneluxNV), were carried out. The effect of diet in zebrafish larvae and juvenile fish was evaluated by the determination of the survival and growth parameters as well as by the analysis of the development at the tissue, cellular and molecular levels in three distinct developmental stages. For that, histological, gene expression and immunohistochemical tools applied to molecular markers of the skeletal development (matrix Gla protein – mgp – and osteocalcin – oc) and digestive tract development (amylase and trypsin) were used. The assessment of bone remodeling regions and a histological analysis of the digestive system were also carried out. The obtained data suggest that rotifers are not appropriate for the larval requirements of this species, presenting the lowest survival and growth values. These data were also supported at the molecular level. Artemia nauplii and a weaning to inert food at 15 days post fertilization does not seem to be, also, an appropriate feeding regime. Comparatively, a diet composed exclusively by Artemia nauplii presented higher development-related parameters. These data suggest that this is a suitable food regime, as it has been argued by several authors. A daily mixture of foods also seems to be suitable to zebrafish healthy development. This work showed that, in zebrafish early development Artemia nauplii should used as food and could be, possibly, supplemented with other foods to obtain better results.