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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Efeito do Piriproxifeno sobre o desenvolvimento, par?metros comportamentais e end?crinos em larvas e adultos de Peixe-zebra (Danio rerio)

Gusso, Darlan 21 February 2018 (has links)
Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2018-04-04T12:33:24Z No. of bitstreams: 1 DARLAN_GUSSO_DIS.pdf: 1507228 bytes, checksum: e2389f511956dbb64bb7b767d8f73e40 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-04-19T16:26:33Z (GMT) No. of bitstreams: 1 DARLAN_GUSSO_DIS.pdf: 1507228 bytes, checksum: e2389f511956dbb64bb7b767d8f73e40 (MD5) / Made available in DSpace on 2018-04-19T16:43:13Z (GMT). No. of bitstreams: 1 DARLAN_GUSSO_DIS.pdf: 1507228 bytes, checksum: e2389f511956dbb64bb7b767d8f73e40 (MD5) Previous issue date: 2018-02-21 / 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.

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