Ultra-estrutura do intestino médio de Cimex hemipterus Fabricius (Hemiptera:Cimicidae)

• Autor(a) principal: Azevedo, Dihego de Oliveira
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2384
• topic: Percevejo; Sistema digestivo; Zoologia; Bed-bugs; Midgut; Zoology; CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL

This work investigated the ultrastructure of the midgut cells of Cimex hemipterus (Hemiptera: Cimicidae) at different times after blood meal. Adults of C. hemipterus were feed on quail s blood (Coturnix coturnix) and starved for one, three, five, seven, ten and fifteen days, when the insects had their midgut dissected and divided in anterior portion (AMG), median portion (MMG) and posterior portion (PMG). The obtained material was processed for analyses under transmission electron microscopy. The midgut of C. hemipterus has a single layer of columnar or cubic digestive cells and regenerative cells onto a basal lamina surrounded by muscle cells. The midgut digestive cells have microvilli and perimicrovillar membranes at the apical portion. The apical cytoplasm has mitochondria, while the median portion showed rounded nucleus with descondensed chromatin and a well developed nucleolus. The basal region of the cells has a developed basal labyrinth associated with mitochondria. The regenerative cells have electron-dense cytoplasm with mitochondria, rough endoplasmatic reticulum and a rounded nucleus. In the AMG the digestive cells have many spherocristals, lipid inclusions, glycogen deposits and electron-lucent vacuoli, suggesting that this midgut region play a role in water absorption, ion regulation, digestion and storage of lpids and sugars. The MMG cells have secretory granules in the apical cytoplasm, lysosomes and large amounts of rough endoplasmatic reticulum, suggesting that this midgut region was active in the blood digestion. The PMG cells also presented secretory granules, lysosomes, rough endoplasmatic reticulum and spherocristals, indicating blood digestion and ion and water absorption activities. Endocrine cells were found in the PMG. Electron-dense granules, pobably involved in heme and iron detoxification were observed in the three midgut regions. The structural similarity of the C. hemipterus midgut with that organ of other blood-feeding Hemiptera suggests that their alimentary habit had a common ancestral origin.