Caracterização morfológica e da expressão de proteínas no intestino médio de Aedes aegypti durante a metamorfose e submetido a diferentes dietas

• Ano de defesa: 2014
• Autor(a) principal: Fernandes, Kenner Morais
• Orientador(a): Martins, Gustavo Ferreira
• Banca de defesa: Games, Patrícia Dias , Oliveira, Leandro Licursi de , Ortigão, José Marcelo Ramalho , Gontijo, Nelder de Figueiredo
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Biologia Celular e Estrutural
• Departamento: Análises quantitativas e moleculares do Genoma; Biologia das células e dos tecidos
• País: BR
• Palavras-chave em Português: Aedes aegypti - Morfologia; Alimentação; Metamorfose; Proteínas; Intestino médio
• Palavras-chave em Inglês: Aedes aegypti - Morphology; Power; Metamorphosis; Proteins; Intestine average
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL
• Link de acesso: http://locus.ufv.br/handle/123456789/279

The larvae of the yellow fever mosquito Aedes aegypti live in the water, feeding on microorganisms and organic matter decomposition. After metamorphosis, adults emerge and feed on sap. However, for the maturation of eggs, the A. aegypti females need a blood meaL This variation of the diets is possible due to the midgut remodeling undergoes during metamorphosis, allowing adaptation to different diets depending on life stages. After ingestion, the blood is stored and digested into midgut, which is the fírst organ víruses, such as Dengue, yellow fever and other infect. The midgut epithelium of A. aegypti Compríses three Cell typesz digestive (responsible for digestion and absorption of nutrients), regenerative (stem, undifferentiated Cells) and enteroendocrine (neuropeptides secretory) Cells. During metamorphosis, the digestive Cells are replaced by new adult digestive Cells by differentiation of regenerative ones. In the present study morphological and biochemical aspects of the metamorphosis of the midgut were investigated, íncluding the differentíation and the quantificatíon of dividing regenerative and enteroendocrine cells at different developmental stages [fourth ínstar larvae - L4, female whíte pupae - WP and pupae 24 and 48 h (P24 and P48, respective1y) after ecdysis, and 50 newly-emerged (NE) adult females] by means líght microscopy and transmission electron microscopy. In addition, the proteins synthesized by the midgut in these stages and in sugar- and b1ood-fed adult females (SA and BA, respective1y) were also studied. The lysis of digestive Cells, as well as the proliferation of regenerative Cells, begin in the anterior region of L4 midgut Simultaneously, the proliferation of regenerative Cells begins in the anterior region of the larval midgut, moving to the posterior region in P48 and NE. The effects of the neocotinoid insectícíde imídacloprid Was also tested in the mosquito midgut Third instar larvae (L3) were treated with two subletal Concentratíons (3 and 15 ppm) of insecticide, and the midgut was examined in L4, P24, P48 and NE. Subletal Concentrations of imidacloprid inhíbít the proliferation and differentíation of regenerative Cells, often leading to cell damaged through their nuclear DNA fragmentation. This inhibition has led to the reduction of the digestive and endocrine Cell numbers, and the mídgut of NE Consists of mostly vacuolatedlincompletely formed digestive Cells. Therefore, the imidacloprid exposition during juvenile stages, impair the normal midgut development in NEs, and they may not be able to get/digest a blood meaL The mídgut of NE has higher expression of proteins related to energy and protein metabolisms, cell signaling and transport. The mídgut of SA and BA express more proteins associated to the protein biosynthesis process. In the mídgut of pupae, several proteins essential for the organ remodeling are expressed, but the peak expression of these proteins occurs at the end of remodeling process in NE. Not surprising1y, in SA and BA there is a high expression of proteins associated to the digestion of sugar and blood, respective1y. In the present Work, several morphological and biochemical aspects of the mídgut of A. aegypti are investigated, íncluding the repertoire of differentially expressed proteins during mídgut development and in the midguts of individuals under different feeding conditions. Morpho-physiological processes that occur during the development and functioning of this organ are Crucial to the survival of this vector mosquito and are discussed.