Aspectos Ultraestruturais, Histoquímicos e Proteicos do intestino médio de Lutzomyia (Nyssomyia) umbratilis Ward e Fraiha, 1977.
Sand fly Lutzomyia (Nyssomyia) umbratilis is the primary vector of Leishmania (Viannia) guyanensis in the Amazon region. Infection occurs when the blood supply of the female sandfly. Protozoa are then confined to the digestive tract of the insect. During several steps of their development, the flage...
| Autor principal: | Gomes, Luís Henrique Monteiro |
|---|---|
| Grau: | Tese |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
|
| Assuntos: | |
| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/12365 http://lattes.cnpq.br/2033999971851983 |
| Resumo: |
|---|
|
Sand fly Lutzomyia (Nyssomyia) umbratilis is the primary vector of Leishmania (Viannia) guyanensis in the Amazon region. Infection occurs when the blood supply of the female sandfly. Protozoa are then confined to the digestive tract of the insect. During several steps of their development, the flagellates are attached to the gut wall by flagellum. However, the parasite needs to escape of a number of barriers in the sand fly gut before a complete blood meal digestion. Peritrophic matrix (PM) secreted by blood-sucking insect is one of those barriers. In this context, imaging of different regions of the midgut and PM, determination of protein composition of the latter need to be thoroughly investigated. Females of L. umbratilis, were collected in a military training area (CIGS, Manaus-Itacoatiara, AM, BR) and fed experimentally in rats. The sandfly's midgut and PM were analysed, timeframe of the PM formation after the blood meal ingestion and its degradation were determined. Important morphological details of the L. umbratilis sand fly PM and of the midgut were studied by transmission (TEM) and scanning (SEM) electron microscopies, its chemical composition was analysed by histochemistry. Complete formation of the PM was observed in 24 h in the dissections. It has a gelatinous aspect and degrades in 72 h. The second PM is secreted after a second- new blood meal. A well-formed fibrillar network structure of the PM was observed by TEM after 24 h, as well as its continuous degradation in 72 h. The ecto-peritrophic face of the midgut was found to be a thick mass with several transversal bands, the latter may evidently be attributed to muscles of the abdominal region, and the PM demonstrated the presence of lumps. Histochemical analysis showed that main PM component is protein, followed by glycoproteins (with different carboxylated and sulfated glycans) and neutral glycoconjugates. The proteins separated from the of midgut and PM of L. umbratilis fed in an interval of 24h to 72h were investigated using the 2-D gel electrophoresis (2-DE) and sequenced by ESI-QToF mass spectrometry. Also, one has to consider that genome of Lutzomyia has not been sequenced up to date. Thus, it was interesting to find out that 60 proteins identified by 2-DE were not correlated with those already deposited in known databases (NCBI, UniProtKB, FlyBast), among the total of 81 protein expressed. In this study, 21 proteins classified as glycoproteins (5), proteoglycans (3), nucleoprotein (7) and chromoprotein (1) were identified, five of them with unknown function. Some of those relate to the matrix formation, resistance, adhesion, structure, maintenance and degradation. For the first time, the PM structure is described in detail for L. umbratilis species using a combination of electron microscopy (SEM and TEM) and histochemical analysis. Possible roles of the PM structural components and their importance for the development of Leishmania parasites are discussed. |