Leaf emergences in Microlepis oleaefolia (DC.) Triana (Melastomataceae) and their probable function: An anatomical and ultrastructural study

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

Leaf glands act as nectaries in Diplopterys pubipetala (Malpighiaceae)

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

Gastric anti-ulcer activity of leaf fractions obtained of polar extract from Wilbrandia ebracteata in mice

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

Cyclin D1 gene polymorphism as a risk factor for squamous cell carcinoma of the upper aerodigestive system in non-alcoholics

Squamous cell carcinoma of the upper aerodigestive tract (UADT) is associated with environmental factors, especially tobacco and alcohol consumption. Genetic factors, including cyclin D1 (CCND1) polymorphism have been suggested to play an important rote in tumorigenesis and progression of UADT cancer. To investigate the relationship between CCND1 polymorphism on susceptibility for UADT cancers, 147 cancer and 135 non-cancer subjects were included in this study. CCND1 genotype at codon 242(G870A) in exon 4 was undertaken using denaturing high performance liquid chromatography (DHPLC) and DNA sequencing. Significant odds ratio (OR) of the AA + GA genotypes [OR = 7.5 (95% Cl: 1.4-39.7)] was observed in non-drinkers but for non-smokers a non-significant [OR = 5.4 (95% Cl: 0.9-31.4)] was found in the adjusted model. These results suggest that allele A may be a risk factor for UADT cancer, especially in non-alcoholics. However, further epidemiological studies are needed to establish the exact role of CCND1 polymorphism and the development of UADT cancers. (C) 2004 Elsevier Ltd. All rights reserved.

Acid phosphatase polymorphism within and among populations of Cauliflower (Brassica oleracea var botrytis)

Eighty-one lines of cauliflower (Brassica oleracea var. botrytis) from 12 populations used to produce commercial hybrids in Brazil were screened for polymorphism in the acid phosphatase system, in order to evaluate the usefulness of this marker for the determination of the parental contamination level in hybrid seeds. Little polymorphism was detected in the examined lines, but the system appeared to be very useful for hybrid identification, since the only condition required was polymorphism between the two parental lines. If the analyzed lines were used for hybrid production, 8.4% and 12.3% of the possible crosses would result in hybrids which can be positively identified using the APS-1 and B1 loci, respectively. If only one plant of each homozygous type (SS or FF) was analyzed in each population, 41% and 50% of the possible crosses would result in hybrids which can be positively identified using the APS-1 and B1 loci, respectively.

Mitochondrial DNA polymorphism and heteroplasmy in populations of Aedes aegypti in Brazil

The tropical mosquito Aedes aegypti (Diptera: Culicidae) is the most important domestic vector of urban yellow fever and dengue viruses. Ae. aegypti originated from Africa and was probably introduced into Brazil during the colonial period through embarkations, and dengue epidemics soon followed. Genetic analysis of 12 Ae. aegypti populations from five states in Brazil was conducted based on two mitochondrial DNA fragments: cytochrome oxidase I and NADH dehydrogenase subunit 4. Analyses comparing individual haplotypes indicated the existence of two well-defined clades, probably representing two mitochondrial lineages. Analysis of molecular variance showed significant variability in genetic structure among collections within groups. Mantel regression analysis showed a correlation between genetic and geographic distances, mainly because of northern and northeastern populations, in comparison with those in the southeast. The population from Santos, the largest port in Brazil, showed the greatest diversity, with 10 unique haplotypes, an indication of recent introductions that have not yet spread to other Brazilian cities. Different mitochondrial DNA sequences were found in three specimens, indicating the presence of heteroplasmy.

Single Nucleotide Polymorphism Markers in Aedes aegypti Populations in Brazil

Single nucleotide polymorphisms (SNPs) were investigated in eighteen genes of sixteen populations of Aedes aegypti in Brazil. Eight SNP markers were selected in nine genes and surveyed in A. aegypti populations of three localities in different geographical locations. SNPs revealed significant genetic differentiation among populations recently analyzed by mitochondria DNA (mtDNA) and represented by a single genetic group (lineage). Results suggest that a haplotype derived from mtDNA analysis could be represented by different Aedes lineages revealed by SNP characterization. Genetic distances (pairwise F(ST)), AMOVA and cluster analyses indicated a high genetic structure for the A. aegypti populations investigated by SNPs. This set of SNP markers represents a useful tool for genetic studies in A. aegypti populations

Characterization of eight single nucleotide polymorphism markers in Aedes aegypti

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

Changes in leaf proline and fruit production induced by potassium stress in eggplant

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diet of invertebrates sampled in leaf-bags incubated in a tropical headwater stream

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Differentiation in Selection of Dicots and Grasses by the Leaf-Cutter Ants Atta capiguara, Atta laevigata and Atta sexdens rubropilosa

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

Colonization of rocky and leaf pack substrates by benthic macroinvertebrates in a stream in southeast Brazil.

A comparative analysis was conducted of the colonization by benthic macroinvertebrates of rocky and leaf pack substrates, both natural and artificial. This colonization was evaluated by season, with the objective of ascertaining the influence of rainfall on the rate of colonization. The total density of macroinvertebrates after 21 days of colonization was significantly greater in the dry than in the wet season. When the substrate types were compared, artificial leaf pack substrate presented the smallest density for both seasons. In the wet season, Chironomidae, Leptohyphidae, Hydropsychidae, Elmidae, immature stages of Trichoptera, and Hydroptilidae showed a more representative density. In the dry season, Chironomidae, Baetidae and Oligochaeta were the most abundant taxa. The artificial rocky substrate used in this experiment was the most appropriate, due to its resemblance with natural substrate conditions in terms of the maintenance of the structural integrity of the substrate throughout the experimental period. Successional and seasonal effects were of great relevance, playing an important role in the colonization process.

Fat body in some genera of leaf-cutting ants (Hymenoptera : Formicidae). Proteins, lipids and polysaccharides detection

The comparative histochemical analysis of the fat body of workers belonging to the basal species Cyphomyrmex rimosus and Mycetarotes parallelus and to derived species Acromyrmex disciger and Atta laevigata revealed that this tissue is constituted mainly by cells denominated trophocytes and oenocytes. The trophocytes of all species studied here were characterized mainly by the proteins and lipids synthesis and storage, being the derived species the ones who have presented higher quantity of lipids in the trophocytes when compared to the trophocytes of basal species. In workers M. parallelus and A. laevigata, besides proteins and lipids, there has being observed the presence of polysaccharides, however, in C. rimosus and A. disciger these elements were detected in lower quantities. The histochemical studies of the oenocytes of basal and derived species revealed significant presence of proteins as well as lipids in these cells. In the oenocytes of derived species A. disciger and A. laevigata a higher quantity of lipidic inclusions has being observed, when compared to the basal species. (c) 2005 Elsevier Ltd. All rights reserved.

The intramandibular gland of leaf-cutting ants (Atta sexdens rubropilosa Forel 1908)

The eusociality developed in Hymenoptera and Isoptera is driven by an efficient interaction between exocrine glands and jointed appendages, both in close interaction with the environment. In this context, the mandible of ants plays an important role, since, in addition to being the main jointed appendage, it possess glandular functions. As an example we might name the two glands associated with the mandible: the mandibular and the intramandibular glands. The intramandibular gland is found inside the mandible and consists of a hypertrophied secretory epithelium and secretory cells in the mandible's lumen. The secretion of the secretory epithelium is liberated through intracuticular ducts that open at the base of hairs at the mandible's surface. The secretion of the intramandibular gland (epithelium and secretory cells) reacted positively to tests for the detection of polysaccharides and proteins, thus suggesting that it consists of glycoproteins. The ultrastructure of the secretor epithelium presents variations related to the developmental stage of the individual, showing a large number of ribosomes and microvilli close to the cuticle in young individuals, while in the older specimens it was possible to note the formation of ail intracellular reservoir. These variations of secretory epithelium, as also the interaction between the cellular groups inside the mandible, are important information about this gland in leaf-cutting ants. (c) 2005 Elsevier Ltd. All rights reserved.

The functional morphology of the metapleural gland of the leaf-cutting ant Atta laevigata (Formicidae: Attini)

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