Monitoring the positioning of short polycationic peptides in model lipid bilayers by combining hydrogen/deuterium exchange and electrospray ionization mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The dynamics of RNA participation in the vitellogenesis of Rhipicephalus sanguineus ticks Latreille 1806 (Acari:Ixodidae). I. Nucleoli or Cajal bodies?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Toxicity of trifluralin herbicide in a representative of the edaphic fauna: Histopathology of the midgut of Rhinocricus padbergi (Diplopoda)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The dynamics of RNA participation in the vitellogenesis of Rhipicephalus sanguineus ticks Latreille 1806 (Acari: Ixodidae). I. Nucleoli or Cajal bodies?

To understand the morphological and histological aspects of internal systems of ticks has become important matter since these arthropods have an impact in the areas of the economy and public health. In this context, this study has provided morphological data on female germinative cells of Rhipicephalus sanguineus ticks, ectoparasites of dogs that maintain a close relationship with human on a daily basis. Oocytes of engorged females were analyzed, through the PAS reaction (detection of polysaccharides) counterstained by methyl green (detection of RNA) revealing information that allowed to infer for the first time the presence of Cajal bodies, in the germinal vesicles (nuclei) of developing oocytes, as well as showing how the RNA and the polysaccharides are involved in the dynamics of the vitellogenesis in this species. [copyright] 2010 Elsevier Ltd. All rights reserved.

Fat body cells of female reproductive castes of Attini ants (Hymenoptera: Formicidae): An ultrastructural and chemical analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Virus present in the reproductive tract of asymptomatic drones of honey bee (Apis mellifera l.), and possible infection of queen during mating

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The neurotoxicological effects of mastoparan Polybia-MPII at the murine neuromuscular junction: an ultrastructural and immunocytochemical study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fine structure of Mytella falcata (Bivalvia) gill filaments

Bivalve filter feeders are sessile animals that live in constant contact with water and its pollutants. Their gill is an organ highly exposed to these conditions due to its large surface and its involvement in gas exchanges and feeding. The bivalve Mytella falcata is found in estuaries of Latin America, on the Atlantic as well as the Pacific Coast. It is commonly consumed, and sometimes is the only source of protein of low-income communities. In this study, gill filaments of M. falcata were characterized using histology, histochemistry and transmission electron microscopy for future comparative studies among animals exposed to environmental pollutants. Gill filaments may be divided into abfrontal, intermediate and frontal zones. Filaments are interconnected by ciliary discs. In the center of filaments, haemocytes circulate through a haemolymph vessel internally lined by an endothelium and supported by an acellular connective tissue rich in polysaccharides and collagen. The abfrontal zone contains cuboidal cells, while the intermediate zone consists of a simple squamous epithelium. The frontal zone is composed of five columnar cell types: one absorptive, mainly characterized by the presence of pinocytic vesicles in the apical region of the cell; one secretory, rarely observed and three ciliated with abundant mitochondria. All cells lining the filament exhibit numerous microvilli and seem to absorb substances from the environment. PAS staining was observed in mucous cells in the frontal and abfrontal zones. Bromophenol blue allowed the distinction of haemocytes and detection of a glycoprotein secretion in the secretory cells of the frontal region. The characteristics of M. falcata gill filaments observed in this study were very similar to those of other bivalves, especially other Mytilidae, and are suitable for histopathological studies on the effect of water-soluble pollutants. (C) 2007 Elsevier Ltd. All rights reserved.

Ultrastructure of the mature testicular vesicle of Pseudonannolene tocaiensis Fontanetti, 1996 (Diplopoda, Pseudonannolenidae)

The mature testicular vesicles of the species Pseudonannolene tocaiensis have three portions: a peripheral portion; a central portion that is typically secretory and between these two an intermediary portion, a lumen filled with spermatozoa. Both secretory and peripheral portions present the same type of cells. The ultrastructural analysis of the peripheral portion suggests it is involved in hormone synthesis. The secretory portion probably contributes to the production of spermatic fluid, compensating for the absence of male accessory glands in this species. (c) 2007 Elsevier Ltd. All rights reserved.

Assessment of the Toxic Potential of Sewage Sludge in the Midgut of the Diplopod Rhinocricus padbergi

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ultrastructural features of the hypopharyngeal glands in the social wasp Polistes versicolor (Hymenoptera : Vespidae)

The wasps of the genus Polistes have been considered the key to understanding the evolution of social behavior in Hymenoptera. Several studies have shown that the development of organized insect societies was accompanied by the evolution of structures like exocrine glands, which became specialized to perform specific functions. This article investigates the ultrastructural and cytochemical features of the hypopharyngeal glands of Polistes versicolor. These glands have been studied in depth in social bees, where they occur only in nurses and produce the royal jelly. Our results revealed that these glands basically did not vary among individuals or between sexes. They are constituted by spherical cells, each with a large nucleus and well-developed rough endoplasmic reticulum. Secretion vesicles are abundant, but lipid droplets were not observed, indicating that these glands may not have a role in pheromone synthesis. Acid phosphatase was detected in lysosomes, and also free in the cytosol, but did not seem to be related with cell death. Thus, our results suggest that the hypopharyngeal glands of P. versicolor may not have a specialized social role, but could produce digestive enzymes.

Ultrastructure of the intramandibular gland of workers and queens of the stingless bee, Melipona quadrifasciata

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nodule ultrastructure and initial growth of Anadenanthera peregrina (L.) Speg. var. falcata (Benth.) Altschul plants infected with rhizobia

The anatomy and ultrastructure of root nodules of Anadenanthera peregrina var. falcata (Leguminosae-Mimosoideae) were analysed, as was plant growth. To ensure that nodules developed, seedlings were inoculated with a mixture of six strains of rhizobia. Nodules were produced that differed in appearance-and probably also effectiveness-but their structure was similar and they showed characteristics typical of indeterminate nodules, such as persistent meristematic tissue and a gradient of cells at different stages of development. Many starch grains were present in inner cortex cells and interstitial cells of infected tissue. Infected cells were densely packed with bacteroids, which contained many poly-beta-hydroxybutyrate granules. The high incidence of these granules, together with high levels of starch accumulation in interstitial cells, suggested low N-2-fixation efficiency of the rhizobia isolates used for inoculation. In the symbiosomes of early-senescent infected cells, reticulum-like structures, small vesicles and a fibrillar material were observed; these may be related to bacteroid degradation. In the cytoplasm of late-senescent infected cells, many vesicles and membrane-like structures were observed, probably associated with membrane degradation of bacteroids and peribacteroids. The total biomass of plants inoculated with rhizobia was low and their xylopodia and shoots had low levels of N compared with non-inoculated plants fertilized with ammonium nitrate. However, inoculated plants did not show N-deficiency symptoms and grew better than non-inoculated plants without N fertilization. These growth results, together with ultrastructural observations of nodules, suggest that nitrogen fixation of rhizobia isolates associated with Anadenanthera peregrina var. falcata roots is poor. (C) 2002 Annals of Botany Company.

Cell localization of the anti-inflammatory protein annexin 1 during experimental inflammatory response

The localization of the glucocorticoid-inducible protein annexin 1 (ANX-1) in leukocytes during the process of experimental inflammation has been studied using immunocytochemistry. ANX-1 immunoreactivity was detected in extravasated neutrophils and eosinophils as well as in resident tissue mast cells. Following injection of carrageenin, the mesenteric tissue was highly inflamed with large presence of leukocytes (predominantly neutrophils with a small percentage of eosinophils) adherent to post-capillary venules and extravasated in the perivascular tissue. ANX-1 immunoreactivity was detected in the cytosol of neutrophils and eosinophils mainly associated with granules and/or vesicles. A good degree of localization in the endosomes was observed in the neutrophils, In both cell types, some ANX-1 immunoreactivity in the nucleus and in the plasma membrane was also detected. Resident mast cells were also activated. Mast cells were positive for ANX-1, without apparent changes in protein content in relation to their activation status. Degranulated mast cells still presented ANX-1 associated with the granule matrix. In conclusion, this study demonstrated the presence of ANX-1 in leukocytes that play a central role in the host inflammatory response. These are the extravasating polymorphonuclear cells, or the resident mast cells. These data provide morphological support to the notion that endogenous and exogenous ANX-1 are able to modulate the reactivity of these cell types, and more generally, of the experimental inflammatory reaction.

Cytochemical characterization of Triatoma infestans and Panstrongylus megistus salivary gland cells (Hemiptera, Reduviidae, Triatominae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)