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1.
Genet Mol Res ; 8(2): 738-43, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19554774

RESUMEN

Only a few decades after 1492, when Christopher Columbus arrived on a Caribbean island and Pedro Alvares Cabral claimed Brazil for Portugal in 1500, a German mercenary gave the first description of stingless bees in 1557. He got to know them when he was imprisoned for months by an anthropophagous tribe in the coastal region of Santos, today in the State of São Paulo. This rather short but nevertheless extremely exact record on stingless bees is hidden in the first book on Brazil. Three species and important aspects of their life history were treated. This early description has been completely overlooked by bee scientists until now. My note intends to close this evident gap.


Asunto(s)
Abejas , Publicaciones , Animales , Brasil
2.
Genet. mol. res. (Online) ; Genet. mol. res. (Online);4(3): 465-472, 2005. graf, ilus
Artículo en Inglés | LILACS | ID: lil-444966

RESUMEN

The ectoparasitic bee mite, Varroa destructor, is highly adapted to its natural and adopted honey bee hosts, Apis cerana and Apis mellifera. Adult females perforate the integument of bee pupae in such a way that they and their progeny can feed. We examined the wounds that founder females made, and usually found one, and rarely up to three, integumental wounds on pupae of A. mellifera multiply infested by V. destructor. The punctures were mainly on the 2nd abdominal sternite of the host. These perforations are used repeatedly as feeding sites by these hemolymph-sucking mites and by their progeny. The diameter of the wounds increased during pupal development. In brood cells containing 4-5 invading female mites and their progeny, healing of the wound is delayed, normally occurring just before the imaginal moult of the bee pupa. These wounds are subject to microbial infections, and they are relevant to the evolution of behavioral traits in these parasitic mites and their relations to host bees.


Asunto(s)
Animales , Masculino , Femenino , Abejas/parasitología , Mordeduras y Picaduras/parasitología , Ácaros/fisiología , Azul de Tripano , Conducta Alimentaria , Microscopía Electrónica de Rastreo , Mordeduras y Picaduras/patología , Pupa/parasitología , Pupa/ultraestructura , Interacciones Huésped-Parásitos
3.
Genet. mol. res. (Online) ; Genet. mol. res. (Online);4(4): 624-641, 2005. ilus, graf
Artículo en Inglés | LILACS | ID: lil-444862

RESUMEN

Diploid males have long been considered a curiosity contradictory to the haplo-diploid mode of sex determination in the Hymenoptera. In Apis mellifera, 'false' diploid male larvae are eliminated by worker cannibalism immediately after hatching. A 'cannibalism substance' produced by diploid drone larvae to induce worker-assisted suicide has been hypothesized, but it has never been detected. Diploid drones are only removed some hours after hatching. Older larvae are evidently not regarded as 'false males' and instead are regularly nursed by the brood-attending worker bees. As the pheromonal cues presumably are located on the surface of newly hatched bee larvae, we extracted the cuticular secretions and analyzed their chemical composition by gas chromatograph-mass spectrometry (GC-MS) analyses. Larvae were sexed and then reared in vitro for up to three days. The GC-MS pattern that was obtained, with alkanes as the major compounds, was compared between diploid and haploid drone larvae. We also examined some physical parameters of adult drones. There was no difference between diploid and haploid males in their weight at the day of emergence. The diploid adult drones had fewer wing hooks and smaller testes. The sperm DNA content was 0.30 and 0.15 pg per nucleus, giving an exact 2:1 ratio for the gametocytes of diploid and haploid drones, respectively. Vitellogenin was found in the hemolymph of both types of imaginal drones at 5 to 6 days, with a significantly lower titer in the diploids.


Asunto(s)
Animales , Masculino , Femenino , ADN , Abejas/genética , Diferenciación Sexual/genética , Diploidia , Espermatozoides/química , Haploidia , Cromatografía de Gases y Espectrometría de Masas , Hemolinfa/química , Larva , Vitelogeninas/sangre
4.
Parasitol Res ; 94(2): 134-40, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15322923

RESUMEN

The intracellular parasite Trypanosoma cruzi, the causative agent of Chagas disease, is known to comprise heterogeneous populations. One possibility to explain the obviously distinct phenotypes of different T. cruzi strains is differential expression of particular genes. This could result in environmental adaptations of the parasite within host organs, leading to distinct clinical symptoms. With the aim of identifying differentially expressed genes, we examined different T. cruzi strains by suppression subtractive hybridization analysis. The isolated clones were sequenced and Blasted for sequence-homology with known T. cruzi genes. A stage-specific glycoprotein (82gp), an 85-kDa protein with homology to heat-shock proteins, a beta-tubulin gene, a hexosetransporter, a dehydrogenase/ prostaglandin F2alpha-synthase and a cathepsin B-like protease were identified. The expression of these genes was analyzed by RT-PCR. Diverse expression patterns were detected for different T. cruzi strains, but no specific correlation between the gene expression and the classification of groups could be found. We discuss the presumed importance of these T. cruzi gene expression patterns for future strategies of molecular therapy of Chagas disease. For pathological studies, other parameters such as distinct gene/antigen expression could also be of interest, because they probably likewise correlate with distinct phenotypes.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , Trypanosoma cruzi/clasificación , Animales , Enfermedad de Chagas/parasitología , ADN Protozoario/análisis , Humanos , Estadios del Ciclo de Vida , Hibridación de Ácido Nucleico/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Trypanosoma cruzi/genética , Trypanosoma cruzi/crecimiento & desarrollo
5.
Parasitol Res ; 88(7): 609-16, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12107452

RESUMEN

Trypanosoma cruzi populations are characterized by diverse morphology, heterogeneous biological behavior, high genetic variability, and distinctly different clinical courses. The first objective of this work was to characterize different strains of T. cruzi with various molecular markers [simple-sequence-repeat PCR, randomly amplified polymorphic DNA (RAPD)-PCR, mini-exon genes]. All examined strains could be divided into two major lineages. Only one strain showed a different banding pattern in RAPD-PCR, which could be a further indication of the existence of a third lineage. The second aim was to examine the biological behavior of the different strains. Two animal models, Calomys callosus and Mus musculus, were infected. The results provide strong evidence that the biological behavior of the strains is not only lineage-specific. It appears that all factors, such as the infecting strain belonging to a certain lineage, the predominant morphological form of the isolate, and the immune response of the respective infected host, play an important role in the course of this infection.


Asunto(s)
Ratones/parasitología , Muridae/parasitología , Parasitemia/fisiopatología , Trypanosoma cruzi/genética , Animales , Enfermedad de Chagas/fisiopatología , ADN Protozoario/genética , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Geografía , Humanos , Reacción en Cadena de la Polimerasa , Especificidad de la Especie , Trypanosoma cruzi/crecimiento & desarrollo , Trypanosoma cruzi/aislamiento & purificación
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