Avaliação dos efeitos do brometo de etídio em Drosophila melanogaster (Diptera-Drosophilidae)
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Data
2011-10-31
Autores
Ouchi, Rejane Yuriko [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A cada ano, milhares de novos compostos químicos entram no mercado, e um volume enorme de resíduos é gerado pela atividade humana, existindo uma grande preocupação com relação aos seus efeitos a curto e longo prazo sobre a saúde e o ambiente. Um grande número dessas substâncias químicas é potencialmente perigoso e pode acarretar efeitos biológicos deletérios, sendo que mudanças a nível molecular são usualmente as primeiras respostas detectáveis da perturbação ambiental. Para avaliar os efeitos em sistemas biológicos, são utilizados bioindicadores, organismos sensíveis a agentes tóxicos. O presente trabalho teve por objetivo analisar os efeitos do Brometo de Etídio (BE), substância potencialmente mutagênica, na mosca da fruta (Drosophila melanogaster), realizando-se sempre comparações com o controle positivo, etilmetanosulfonato (EMS). Escolhemos o brometo de etídio por se tratar de uma substância usada frequentemente em métodos de biologia molecular, sendo tida como mutagênica, apesar de não constar como carcinogênico nas listagens da Agência Internacional para Pesquisa de Câncer (IARC). A pesquisa foi feita ao longo de 25 gerações, e em seis gerações (1ª, 5ª, 10ª, 15ª, 20ª, 25ª gerações) foram analisados: (1) os efeitos sobre padrões morfológicos, (2) a produtividade diária ao longo de 15 dias. Além disso, foram analisadas também: (3) alterações bioquímicas em enzimas do sistema oxidativo, acarretadas pela exposição a diferentes concentrações de brometo de etídio e EMS, (4) alterações gênicas: em nível de transposição do elemento transponível Bari-1 e na expressão dos genes que codificam as proteínas catalase, hsp 70 (heat shock protein), superóxido dismutase...
Each year thousands of new chemicals enter the market, and an enormous volume of waste is generated by human activity. Accordingly, there is a great concern regarding their short and long term health and environmental effects. A large number of these chemicals is potentially dangerous and can cause harmful biological effects, and changes at the molecular level are usually the first detectable responses of environmental disturbance. To evaluate the effects on biological systems, are used bioindicators, organisms sensitive to toxic agents. This study aimed to analyze the effects of Ethidium Bromide (EB), a potentially mutagenic substance, in the fruit fly (Drosophila melanogaster), comparing with a positive control, ethylmethanesulfonate (EMS). We chose ethidium bromide because it is a chemical frequently used in molecular biology techniques, and considered as a mutagenic although it is not included in the lists of the International Agency for Research on Cancer (IARC). The survey was conducted over 25 generations, and in six generations (1st, 5th, 10th, 15th, 20th, 25th generations) were analyzed: (1) the effects on morphological patterns, (2) the daily productivity over 15 days. In addition, we also analyzed: (3) biochemical changes in enzymes of the oxidative system brought about by exposure to different concentrations of ethidium bromide and EMS, (4) genetic alterations: level of transposition of the transposable element Bari-1 and expression genes that encode proteins catalase, hsp 70 (heat shock protein), superoxide dismutase 1 and esterase-6 and (5) longevity. Concerning daily productivity, five replicates were done, involving negative and positive controls (not exposed to any mutagen and with EMS, respectively), and three groups exposed to 1, 5 and 30 µM of EB. The results show that there were... (Complete abstract click electronic access below)
Each year thousands of new chemicals enter the market, and an enormous volume of waste is generated by human activity. Accordingly, there is a great concern regarding their short and long term health and environmental effects. A large number of these chemicals is potentially dangerous and can cause harmful biological effects, and changes at the molecular level are usually the first detectable responses of environmental disturbance. To evaluate the effects on biological systems, are used bioindicators, organisms sensitive to toxic agents. This study aimed to analyze the effects of Ethidium Bromide (EB), a potentially mutagenic substance, in the fruit fly (Drosophila melanogaster), comparing with a positive control, ethylmethanesulfonate (EMS). We chose ethidium bromide because it is a chemical frequently used in molecular biology techniques, and considered as a mutagenic although it is not included in the lists of the International Agency for Research on Cancer (IARC). The survey was conducted over 25 generations, and in six generations (1st, 5th, 10th, 15th, 20th, 25th generations) were analyzed: (1) the effects on morphological patterns, (2) the daily productivity over 15 days. In addition, we also analyzed: (3) biochemical changes in enzymes of the oxidative system brought about by exposure to different concentrations of ethidium bromide and EMS, (4) genetic alterations: level of transposition of the transposable element Bari-1 and expression genes that encode proteins catalase, hsp 70 (heat shock protein), superoxide dismutase 1 and esterase-6 and (5) longevity. Concerning daily productivity, five replicates were done, involving negative and positive controls (not exposed to any mutagen and with EMS, respectively), and three groups exposed to 1, 5 and 30 µM of EB. The results show that there were... (Complete abstract click electronic access below)
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Bioquímica, Genética, Toxicologia, Toxicology
Como citar
OUCHI, Rejane Yuriko. Avaliação dos efeitos do brometo de etídio em Drosophila melanogaster (Diptera-Drosophilidae). 2011. 119 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Biociências, Letras e Ciências Exatas, 2011.