Transporte de Vitelogenina no Ovário de Himenóptera Sociais

• Ano de defesa: 2014
• Autor(a) principal: Rönnau, Milton
• Orientador(a): Serrão, José Eduardo
• Banca de defesa: Campos, Lúcio Antonio de Oliveira , Games, Patrícia Dias , Santos, Conceição Aparecida dos
• 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: Vitelogenina; Ovário; Hymenoptera sociais
• Palavras-chave em Inglês: Vitellogenin; Ovary; Hymenoptera sociais
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL
• Link de acesso: http://locus.ufv.br/handle/123456789/269

Vitellogenins are the major proteins of the yolk, synthesized in the fat body, released into the haemolymph and absorbed by the developing oocytes, where they are converted into yolk to be consumed during embryogenesis. The circulating vitellogenin should cross the follicular epithelium barrier surrounding the oocyte. However, the mechanisms by which this protein cross the layer of follicle cells are still poorly understood. The objective of this study was to compare the routes for vitellogenin transport from the haemolymph to the oocyte in social Hymenoptera represented by bees Apis mellifera and Melipona quadrifasciata, wasp Mischocyttarus cassununga and ant Pachycondila curvinodis. The protein contents of the ovaries were similar among species. Some proteins cross-react with antivitellogenin antibody against the ant Ectatomma tuberculatum showing that the species studied had conserved domains in the vitellogenin. In the oocyte chambers of vitellogenic follicles were detected vitellogenin into the follicular cell, oocyte in and the perivitelline space, indicating a transcellular route of the vitellogenin from haemolymph to the perivitelline space in all studied specie. Actin cytoskeleton undergoes restructuring arrangement in response to the transport of the vitellogenin in the follicular cells of vitelogenic follicles. Septate junctions occur in the apical region of follicular cell-cell contact of vitellogenic follicles, resulting in a barrier to the movement of substances in the intercellular space. The vitellogenin within the follicular cells occurs in a membranous reticular system in vitellogenic oocytes. In the ovary of social Himenóptera, vitellogenin is initially carried in the intercellular spaces, which enlarge due to the rearrangement of actin filaments until the median apical portion then, the yolk precursor followis a transcellular route to the previtelline space.