The midgut of Cephalotes ants (Formicidae: Myrmicinae): Ultrastructure of the epithelium and symbiotic bacteria

The ultrastructural analysis of the midgut of Cephalotes atratus. C. clypeatus, and C. pusillus reveled that the midgut epithelium lays on a basal lamina and is composed basically of three cell types: digestive cells, regenerative cells, and goblet cells. In these ants, the rough endoplasmic reticulum, in addition to producing digestive enzymes, is involved in the formation of concretions and ion storage in specialized vacuoles present in the midgut. These concretions are spherocrystals and may contribute to stabilize the pH and to maintain symbiotic bacteria found between microvilli. The ultrastructure analysis of these bacteria revealed the presence of a double envelope typical of gram-negative bacteria. For the three species examined, the ultrastructure similarities are conspicuous, suggesting that this may be the pattern for the genus Cephalotes. Details of the relationship between bacteria and microvilli were examined. (C) 2010 Elsevier Ltd. All rights reserved.

First evidence of an intimate symbiotic association between fungi and larvae in basal attine ants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Symbiotic bacteria and the structural specializations in the ileum of Cephalotes ants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ultrastructural analysis of the fat body in workers of Attini ants (Hymenoptera: Formicidae)

In the present study a comparative morphological analysis of the fat body cells of ant workers of the basal Attini species Cyphomyrmex rimosus and Mycetarotesparallelus, and the derived species Acromynnex disciger and Atta laevigata was conducted. The results revealed that the fat body is located mainly in the abdomen around organs (perivisceral) and near the integument (parietal). The main cells observed are spherical or polygonal trophocytes with a slightly rough surface. The oenocytes, another cell type found, are closely associated with trophocytes, and present a spherical or polygonal shape and a smoother surface. The morphometric analysis showed that the area of trophocytes and oenocytes of C rimosus and M parallelus is significantly smaller when compared to those of A. disciger and A. laevigata. In the cytoplasm of parietal and perivisceral trophocytes and oenocytes, electronlucent droplets (probably lipids) and electrondense granules (probably proteins) indicate the participation of these cells in the storage of these elements, while digestive vacuoles, residual bodies, and multivesicular bodies suggest a role in intracellular digestion. In perivisceral trophocytes and oenocytes of C rimosus, the presence of mitochondria, lamellar rough endoplasmic reticulum, and Golgi complex suggests that these cells synthesize proteins. Based on these data, no significant differences were observed between the fat body cells of basal and derived ants, except regarding the larger size of trophocytes and oenocytes of the derived species A. disciger and A. laevigata. (C) Koninklijke Brill NV, Leiden, 2009

Histochemistry and Protein Profile of The Venom Glands of Workers of Neoponera villosa Ants (Hymenoptera: Ponerinae)

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

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)

Molecular and ultrastructural profiles of the symbionts in Cephalotes ants

The molecular and ultrastructural profiles of the symbionts found in the midgut and ileum of Cephalotes atratus, Cephalotes clypeatus, and Cephalotes pusillus were determined using the V3 region of the bacterial 16S rDNA gene and transmission electron microscopy (T.E.M.). Two samples of C atratus, three of C clypeatus, and six of C. pusillus were analyzed. The coefficients of similarity ranged from 80% to 94% for the samples of symbionts from C. clypeatus and C. atratus, despite being collected in geographically distant sites. The variability within symbionts found in the samples of C. pusillus varied from 29% to 55%, in samples geographically close as well as distant. PCR-DGGE was effective for the purpose of this study and can be considered a versatile tool to analyze gut microbiota. Details of the ultrastructural aspect of these bacteria are presented. (C) 2010 Elsevier Ltd. All rights reserved.

Ileum of the Cephalotes ants: A specialized structure to harbor symbionts microorganisms

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evolution of Substrate Preparation Behaviors for Cultivation of Symbiotic Fungus in Attine Ants (Hymenoptera: Formicidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ant diversity (Hymenoptera: Formicidae) and predation by ants on the different stages of the sugarcane borer life cycle Diatraea saccharalis (Lepidoptera: Crambidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphology, ultramorpholgy and morphometry of the fat body of virgin females and queens of the ants Pachycondyla striata (Hymenoptera : Formicidae)

The fat body cells of virgin females and queens of Pachycondyla striata ants belonging to the subfamily Ponerinae are illustrated from morphologic, ultramorphologic and morphometric viewpoints. Camera lucida drawing techniques were used, as well as scanning electronic microscopy (SEM). Measurements of trophocytes and oenocytes areas in the tissue were recorded. The results showed that in P. striata queens and virgin females the trophocytes are arranged in cord-like formations in association with oenocytes. Trophocytes of both castes had round shapes, with rather vacuolized cytoplasm, whereas oenocytes, being smaller than trophocytes, had more homogeneous cytoplasm. It was also observed that both trophocytes and oenocytes of virgin females were larger than those found in the same queen cellular types.

Diversity of Epigeal Ants (Hymenoptera: Formicidae) in Urban Areas of Alto Tiete

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphophysiological Differences between the Metapleural Glands of Fungus-Growing and Non-Fungus-Growing Ants (Hymenoptera, Formicidae)

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

Antagonistic interactions between garden yeasts and microfungal garden pathogens of leaf-cutting ants

We investigate the diversity of yeasts isolated in gardens of the leafcutter ant Atta texana. Repeated sampling of gardens from four nests over a 1-year time period showed that gardens contain a diverse assemblage of yeasts. The yeast community in gardens consisted mostly of yeasts associated with plants or soil, but community composition changed between sampling periods. In order to understand the potential disease-suppressing roles of the garden yeasts, we screened isolates for antagonistic effects against known microfungal garden contaminants. In vitro assays revealed that yeasts inhibited the mycelial growth of two strains of Escovopsis (a specialized attine garden parasite), Syncephalastrum racemosum (a fungus often growing in gardens of leafcutter lab nests), and the insect pathogen Beauveria bassiana. These garden yeasts add to the growing list of disease-suppressing microbes in attine nests that may contribute synergistically, together with actinomycetes and Burkholderia bacteria, to protect the gardens and the ants against diseases. Additionally, we suggest that garden immunity against problem fungi may therefore derive not only from the presence of disease-suppressing Pseudonocardia actinomycetes, but from an enrichment of multiple disease-suppressing microorganisms in the garden matrix.

Yeasts and filamentous fungi carried by the gynes of leaf-cutting ants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)