Pollen spectrum of propolis samples from São Paulo State, Brazil

The pollen spectrum of propolis is a good indicative of the phytogeographical origin of the bee product and the local flora available for bee visiting. The present study aimed to perform pollen analysis of propolis produced by Apis mellifera L., in the São Paulo State, Brazil. Propolis samples were directly obtained from beekeepers and slides were prepared for qualitative and quantitative analysis of pollen after propolis extraction. According to the results twenty-eight types of pollen were found and distributed in fifteen botanical families. Pollens from Mimosoideae and Myrtaceae types were found in all samples. In São Paulo State, there is a wide variety of vegetal sources which are components of the final propolis composition.

Africanized honeybees in urban areas: a public health concern

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

Combining Experimental Evidence and Molecular Dynamic Simulations To Understand the Mechanism of Action of the Antimicrobial Octapeptide Jelleine-I

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

Comportamento forrageiro de abelhas visitantes de Solanun lycocarpum (Solanaceae) St. Hill e aspectos da biologia floral

A polinização é um serviço indireto prestado pelos ecossistemas, de valor ambiental e econômico para a sociedade humana. Em função dessa importância, a conservação de espécies de abelhas nativas é fundamental e o conhecimento de aspectos da biologia e ecologia dessas espécies é a base para a proposição de planos de manejo e conservação. Neste trabalho, foram feitas observações focais, avaliando os padrões de atividades diárias e sazonais, com ênfase no comportamento de coletas de recursos de abelhas nativas em flores de Solanum lycocarpum, uma espécie em que é característica a síndrome de polinização vibrátil. Os visitantes observados foram dez espécies de abelhas: Apis mellifera L., Oxaea flavescens K.; Centris sp1, Centris sp2, Exomalopsis sp.., Xylocopa suspecta M., Xylocopa frontalis K., Bombus morio S., Bombus atratus F., Trigona sp., além de espécies de abelhas da família Halictidae. As abelhas maiores, como Xylocopa, Oxaea, Centris e Bombus são certamente os polinizadores mais eficientes de Solanum lycocarpum. Isso se deve ao comportamento dessas abelhas nas flores, particularmente em relação à posição da abelha em relação ao cone de anteras quando forrageia e à seqüência de movimentos que cada uma desenvolve nas flores.

Desenvolvimento de uma plataforma analítica para aquisição de imagens moleculares em tecidos animais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Agelotoxin: a phospholipase A(2) from the venom of the neotropical social wasp cassununga (Agelaia pallipes pallipes) (Hymenoptera-Vespidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seasonal vatiations of the chemical composition of Brazilian propolis

The seasonal variations in the chemical composition of Brazilian propolis, collected by two bee subspecies, Africanized Apis mellifera and European Apis mellifera ligustica, have been investigated by GC and GC-MS. The main components of the samples were phenolic compounds, especially cinnamic acid derivatives, the only exception being the autumn sample from Apis mellifera ligustica, where diterpenes predominated. In propolis from both subspecies, diterpenes appeared in summer and reached maximum percentage in autumn, but were absent during the other seasons. The results obtained indicated that both bee subspecies collect propolis from among the same group of plants, and that there are at least two important plant sources, but these remain unidentified.

Caracterização da produção e qualidade físico-química de méis produzidos no Estado de Pernambuco

The present study had as objective contribute to the characterization of beekeeping in the Pernambuco State and evaluate the physical-chemical quality of the honeys produced in the region. For this, was applied a directed formulary to the representative organ of beekeeping class aboutthe productives and technicals aspects of beekeepers. Was obtained 14 samples of honey by Apis mellifera africanized, stored in sterile plastic vessels was sent to the Beekeeping Products Quality Control Laboratory (CEA-UNITAU). Was observed that the most of beekeepers have of 50 to 100 hives (57,14%), 28,57% of 100 to 200 hives and 14,28% more than 500 hives, being that 85,71% produce 30 to 50 kg honey/hives/flowering. All use the standard hive Langstroth and 85,71% obtain their swarm by capture. About the physical-chemical quality of the honey, was observed that moisture content varied from 18,2% to 22,0%, with mean value of 19,80±1,11; the water activity varied from 0,70 to 0,84 aw, with mean value of 0,79±0,05 aw; the total acidity was 24,91±8,99 meq/kg and the average index of hydroxymethylfurfural was 16,32±17,88 meq/kg. The results obtained are according to the quality limits established by the brazilian legislation, excepted the water activity that exceeded the maximum limit of 0,65 aw. The datasobtained in this paper shows the development of beekeeping in Pernambuco State and the honey presents nice quality.

Influence of seasonality and production method on the antibacterial activity of propolis

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

Development and evolution of caste dimorphism in honeybees - a modeling approach

The difference in phenotypes of queens and workers is a hallmark of the highly eusocial insects. The caste dimorphism is often described as a switch-controlled polyphenism, in which environmental conditions decide an individual's caste. Using theoretical modeling and empirical data from honeybees, we show that there is no discrete larval developmental switch. Instead, a combination of larval developmental plasticity and nurse worker feeding behavior make up a colony-level social and physiological system that regulates development and produces the caste dimorphism. Discrete queen and worker phenotypes are the result of discrete feeding regimes imposed by nurses, whereas a range of experimental feeding regimes produces a continuous range of phenotypes. Worker ovariole numbers are reduced through feeding-regime-mediated reduction in juvenile hormone titers, involving reduced sugar in the larval food. Based on the mechanisms identified in our analysis, we propose a scenario of the evolutionary history of honeybee development and feeding regimes.

Vitellogenin content in fat body and ovary homogenates of workers and queens of Melipona quadrifasciata anthidioides during vitellogenesis

Vitellogenin (Vg) is an egg yolk protein that is produced primarily in the fat body of most female insects. In the advanced social structure of eusocial honeybees, the presence of the queen inhibits egg maturation in the workers ovaries. However in the stingless bee Melipona quadrifasciata, the workers always develop ovaries and lay a certain amount of eggs while provisioning the brood cells with larval food during what is known as the worker nurse phase. The present work is a comparative study of the presence of Vg in homogenates of the fat bodies and ovaries of the nurse workers, and the virgin and physogastric queens of M. quadrifasciata. The presence of Vg was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting using Apis mellifera anti-egg antibody. Vg was not detected in the fat bodies or ovaries of the workers, but it was found in the ovaries of virgin and physogastric queens and in the fat body of physogastric queens. The results are discussed, taking into account the reproductive state of the individuals and the other possible roles of Vg, such as a storage protein for metoabolism of other organs.

Hox Gene Expression Leads to Differential Hind Leg Development between Honeybee Castes

Beyond the physiological and behavioural, differences in appendage morphology between the workers and queens of Apis mellifera are pre-eminent. The hind legs of workers, which are highly specialized pollinators, deserve special attention. The hind tibia of worker has an expanded bristle-free region used for carrying pollen and propolis, the corbicula. In queens this structure is absent. Although the morphological differences are well characterized, the genetic inputs driving the development of this alternative morphology remain unknown. Leg phenotype determination takes place between the fourth and fifth larval instar and herein we show that the morphogenesis is completed at brown-eyed pupa. Using results from the hybridization of whole genome-based oligonucleotide arrays with RNA samples from hind leg imaginal discs of pre-pupal honeybees of both castes we present a list of 200 differentially expressed genes. Notably, there are castes preferentially expressed cuticular protein genes and members of the P450 family. We also provide results of qPCR analyses determining the developmental transcription profiles of eight selected genes, including abdominal-A, distal-less and ultrabithorax (Ubx), whose roles in leg development have been previously demonstrated in other insect models. Ubx expression in workers hind leg is approximately 25 times higher than in queens. Finally, immunohistochemistry assays show that Ubx localization during hind leg development resembles the bristles localization in the tibia/basitarsus of the adult legs in both castes. Our data strongly indicate that the development of the hind legs diphenism characteristic of this corbiculate species is driven by a set of caste-preferentially expressed genes, such as those encoding cuticular protein genes, P450 and Hox proteins, in response to the naturally different diets offered to honeybees during the larval period.

The use of Open Reading frame ESTs (ORESTES) for analysis of the honey bee transcriptome

Abstract Background The ongoing efforts to sequence the honey bee genome require additional initiatives to define its transcriptome. Towards this end, we employed the Open Reading frame ESTs (ORESTES) strategy to generate profiles for the life cycle of Apis mellifera workers. Results Of the 5,021 ORESTES, 35.2% matched with previously deposited Apis ESTs. The analysis of the remaining sequences defined a set of putative orthologs whose majority had their best-match hits with Anopheles and Drosophila genes. CAP3 assembly of the Apis ORESTES with the already existing 15,500 Apis ESTs generated 3,408 contigs. BLASTX comparison of these contigs with protein sets of organisms representing distinct phylogenetic clades revealed a total of 1,629 contigs that Apis mellifera shares with different taxa. Most (41%) represent genes that are in common to all taxa, another 21% are shared between metazoans (Bilateria), and 16% are shared only within the Insecta clade. A set of 23 putative genes presented a best match with human genes, many of which encode factors related to cell signaling/signal transduction. 1,779 contigs (52%) did not match any known sequence. Applying a correction factor deduced from a parallel analysis performed with Drosophila melanogaster ORESTES, we estimate that approximately half of these no-match ESTs contigs (22%) should represent Apis-specific genes. Conclusions The versatile and cost-efficient ORESTES approach produced minilibraries for honey bee life cycle stages. Such information on central gene regions contributes to genome annotation and also lends itself to cross-transcriptome comparisons to reveal evolutionary trends in insect genomes.

Transcriptional profiling of Saccharomyces cerevisiae exposed to propolis

Abstract Background Propolis is a natural product of plant resins collected by honeybees (Apis mellifera) from various plant sources. Our previous studies indicated that propolis sensitivity is dependent on the mitochondrial function and that vacuolar acidification and autophagy are important for yeast cell death caused by propolis. Here, we extended our understanding of propolis-mediated cell death in the yeast Saccharomyces cerevisiae by applying systems biology tools to analyze the transcriptional profiling of cells exposed to propolis. Methods We have used transcriptional profiling of S. cerevisiae exposed to propolis. We validated our findings by using real-time PCR of selected genes. Systems biology tools (physical protein-protein interaction [PPPI] network) were applied to analyse the propolis-induced transcriptional bevavior, aiming to identify which pathways are modulated by propolis in S. cerevisiae and potentially influencing cell death. Results We were able to observe 1,339 genes modulated in at least one time point when compared to the reference time (propolis untreated samples) (t-test, p-value 0.01). Enrichment analysis performed by Gene Ontology (GO) Term finder tool showed enrichment for several biological categories among the genes up-regulated in the microarray hybridization such as transport and transmembrane transport and response to stress. Real-time RT-PCR analysis of selected genes showed by our microarray hybridization approach was capable of providing information about S. cerevisiae gene expression modulation with a considerably high level of confidence. Finally, a physical protein-protein (PPPI) network design and global topological analysis stressed the importance of these pathways in response of S. cerevisiae to propolis and were correlated with the transcriptional data obtained thorough the microarray analysis. Conclusions In summary, our data indicate that propolis is largely affecting several pathways in the eukaryotic cell. However, the most prominent pathways are related to oxidative stress, mitochondrial electron transport chain, vacuolar acidification, regulation of macroautophagy associated with protein target to vacuole, cellular response to starvation, and negative regulation of transcription from RNA polymerase II promoter. Our work emphasizes again the importance of S. cerevisiae as a model system to understand at molecular level the mechanism whereby propolis causes cell death in this organism at the concentration herein tested. Our study is the first one that investigates systematically by using functional genomics how propolis influences and modulates the mRNA abundance of an organism and may stimulate further work on the propolis-mediated cell death mechanisms in fungi.

Use of the checkerboard DNA-DNA hybridization technique for bacteria detection in Aedes aegypti (Diptera:Culicidae) (L.)

Abstract Background Bacteria associated with insects can have a substantial impact on the biology and life cycle of their host. The checkerboard DNA-DNA hybridization technique is a semi-quantitative technique that has been previously employed in odontology to detect and quantify a variety of bacterial species in dental samples. Here we tested the applicability of the checkerboard DNA-DNA hybridization technique to detect the presence of Aedes aegypti-associated bacterial species in larvae, pupae and adults of A. aegypti. Findings Using the checkerboard DNA-DNA hybridization technique we could detect and estimate the number of four bacterial species in total DNA samples extracted from A. aegypti single whole individuals and midguts. A. aegypti associated bacterial species were also detected in the midgut of four other insect species, Lutzomyia longipalpis, Drosophila melanogaster, Bradysia hygida and Apis mellifera. Conclusions Our results demonstrate that the checkerboard DNA-DNA hybridization technique can be employed to study the microbiota composition of mosquitoes. The method has the sensitivity to detect bacteria in single individuals, as well as in a single organ, and therefore can be employed to evaluate the differences in bacterial counts amongst individuals in a given mosquito population. We suggest that the checkerboard DNA-DNA hybridization technique is a straightforward technique that can be widely used for the characterization of the microbiota in mosquito populations.