Genetic and morphological variation in the Bulbophyllum exaltatum (Orchidaceae) complex occurring in the Brazilian “campos rupestres”: implications for taxonomy and biogeography

The Bulbophyllum exaltatum complex comprises 15 described taxa, and present a number of unresolved taxonomic questions, especially among populations found in the Brazilian campo rupestre vegetation. Allozymes were examined in 33 populations to determine the degree of genetic variability between them and their degree of differentiation to better define the taxa of this group. Additionally morphometric analyses were also performed on representatives of 24 populations. All of the populations examined demonstrated high levels of variability and none of the species formed distinct groups comprising all of the conspecific populations. However, the populations primarily grouped according to their regional occurrence, with a distinction between populations of the states of Minas Gerais and Bahia, which coincided with the geophysical disjunction of the mountain chains where they occur. It is probable that hybridization or incipient differentiation is contributing to the elevated genetic identity observed among the populations, generating a reticulated grouping pattern.     

Observations on Male Territories in a Carpenter Bee,Xylocopa (Neoxylocopa) hirsutissima Maidl (Hymenoptera,Anthophoridae)

Observations were made on territoriality of ♂♂ of the Brazilian carpenter bee Xylocopa hirsutissima. These territories are found on mountain tops where the ♂♂ hover from 4–6 p.m. in close vicinity of an optical beacon, being a protruding shrub or little tree. Territories are defended against other ♂♂Production of a pheromone by the mandibular glands is supposed. This territoriality as well as that of other species of the genus is considered to be an important aspect of the mating biology.     

Trichophyton mentagrophytes infection in laboratory white mice

Trichophyton mentagrophytes infection was studied in a breeding colony of 42 white mice. Symptoms were observed in only 3 out of the 12 animals shown to carry dermatophyte on their coats.Literature on Trichophyton mentagrophytes infection in mice is reviewed. The use of the technique developed by Mariat & Tapia (16) to isolate dermatophytes on cultures, specially for epidemiological surveys, is postulated.Attention is called to the importance of healthy animals, directly or indirectly, as carriers of fungi and sources of infection to other animals and human beings.

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Resumo E feita uma revisão da literatura sobre infecção, em camundongos, por T. mentagrophytes e descrita uma epizootia em camundongos do biotério da Escola Paulista de Medicina.Dos 42 animais usados para experimentação, 3 apresentavam lesões descamativas na cabeça e dorso. T. mentagrophytes foi isolado, em cultivo, de 2 dos camundongos com lesão e de 10 animais, clinicamente sadios. A tecnica desenvolvida por Mariat & Tapia para isolamento de fungos do tegumento de animais e de pacientes, com ou sem lesões visiveis, em áreas extensas do corpo, parece ser a mais indicada, pela praticabilidade e facilidade de seu uso, principalmente em amplos inquéritos epidemiológicos. Chama-se atenção para a importância dos animais sadios, como vetores de esporos de fungos e fontes de infecção, diretamente ou indirectamente, para o homem e outros animais.

     

Rainforest-to-pasture conversion stimulates soil methanogenesis across the Brazilian Amazon

The Amazon rainforest is a biodiversity hotspot and large terrestrial carbon sink threatened by agricultural conversion. Rainforest-to-pasture conversion stimulates the release of methane, a potent greenhouse gas. The biotic methane cycle is driven by microorganisms; therefore, this study focused on active methane-cycling microorganisms and their functions across land-use types. We collected intact soil cores from three land use types (primary rainforest, pasture, and secondary rainforest) of two geographically distinct areas of the Brazilian Amazon (Santarém, Pará and Ariquemes, Rondônia) and performed DNA stable-isotope probing coupled with metagenomics to identify the active methanotrophs and methanogens. At both locations, we observed a significant change in the composition of the isotope-labeled methane-cycling microbial community across land use types, specifically an increase in the abundance and diversity of active methanogens in pastures. We conclude that a significant increase in the abundance and activity of methanogens in pasture soils could drive increased soil methane emissions. Furthermore, we found that secondary rainforests had decreased methanogenic activity similar to primary rainforests, and thus a potential to recover as methane sinks, making it conceivable for forest restoration to offset greenhouse gas emissions in the tropics. These findings are critical for informing land management practices and global tropical rainforest conservation.Subject terms: Soil microbiology, Microbial ecology     

Studies of cell lipids from the human vaginal and cervical epithelium during the menstrual cycle

The cholesterol fractions of lipids from vaginal washings of 18 women in the estrogenic phase (4 pools, 10 mg each), 16 in the progesteronic phase (4 pools, 10 mg each), and 20 exhibiting atrophy (3 pools, 10 mg each, separated by column chromatography, assayed by colorimetry, were .711 plus or minus .022, 1.227 plus or minus .023, and 1.245 plus or minus .026 mg/10 mg of total lipids, respectively. Cholesterol ester fractions (not identified by thin layer chromatography), similarly assayed, were .327 plus or minus .007, .281 plus or minus .007, and .282 plus or minus .004 mg/10 mg lipids, respectively. Phospholipid fractions, determined by assaying an inorganic phosphorous compound formed from the organic phosphorous, were .494 plus or minus .160, 1.294 plus or minus .596, and 3.204 plus or minus .035 mg/10 mg lipids, respectively. Triglyceride fractions, determined by assaying glycerol yielded by saponification, were 6.222 plus or minus .019, and 4.818 plus or minus .029, and 2.893 plus or minus .010 mg/10 mg lipids, respectively. Unidentified fractions were 2.246, 2.380, and 2.376 mg/10 mg total lipids. The increased amount of choleterol ester and decreased amount of cholesterol in the estrogenic phase is analogois to increased esterification of free cholesterol in keratinization of squamous cells. The phospholipid content, greatest in cells, in atrophy, and least in cells in the estrogenic phase, varies analogously to the decrease of mitochondria of basal squamoius epithelial cells as they move to higher strata. Fat is deposited during differentiation of the vaginal epitheliuml thus triglycerida content increases.     

Trypanosomatid protozoa in fruit of Solanaceae in southeastern Brazil

Fruits of cultivated and indigenous Solanaceae from Southeastern Brazil have been examined for the presence of trypanosomatid flagellates. The 14 species found infected were: Capsicum annuum, C. praetermissum, Lycopersicon esculentum, Nicandra physaloides, Physalis angulata, Solanum sp., S. americanum, S. concinnum, S. diflorum, S. erianthum, S. gilo, S. robustum, S. variable and S. viarum. The pentatomid hemipteran Arvelius albopunctatus experimentally transmitted flagellates to fruits of some species. Cultures of flagellates were obtained from fruits of eight species of Solanaceae and from A. albopunctatus.     

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

The ultrastructural study on the fat body of gynes (virgin queens) of the basal ant species Cyphomyrmex rimosus and Mycetarotes parallelus and the derived Acromyrmex disciger and Atta laevigata queens showed vesicular rough endoplasmic reticulum, Golgi complex, and mitochondria in trophocytes, suggesting the involvement of these cells in protein synthesis, in addition to digestive vacuoles associated with the digestion of endocytosed compounds or rejected cell organelles. Oenocytes, another cell type present in the fat body of these species exhibit mitochondria, digestive vacuoles, and vesicles, indicating a mobilization of compounds by these cells. In A. laevigata, oenocytes also exhibited large storage sites of glycogen, in addition to a well-developed vesicular rough endoplasmic reticulum, suggesting an intensive participation of these cells in protein synthesis. The ultrastructural cytochemistry study also revealed electrodense granules of basic proteins present throughout the cytoplasm of trophocytes. The same was observed in oenocytes, although with smaller amounts of proteins. In the cytoplasm of trophocytes and oenocytes were also found droplets or electrodense granules of lipids. In oenocytes of A. disciger and in trophocytes of A. laevigata, lipids were observed in mitochondria, suggesting that this organelle might be a site of synthesis of these compounds. The chemical analysis of lipids revealed that in gynes, the main compounds present in fat body cells were saturated fatty acids, while in queens, saturated as well as unsaturated fatty acids were found. In conclusion, the present study showed that the fat body cells of gynes and queens, in general, maintained the same compounds and original features through the evolution process of the Attini tribe.     

Proteolytic activites in cell extracts of Trypanosoma cruzi.

Cell extracts of culture forms of Trypanosoma cruzi are capable of hydrolysing substances belonging to 4 different groups of protease substrates: (a) substrates for trypsin-like enzymes: benzoyl-arginine-p-nitroanilide and benzoylarginine-naphtylamide; (b) substrates for aminopeptidases: leucyl, lysl and glutamyl-beta-naphtylamide; (c) a substrate fochymotrypsin-like enzymes: carbobenzoxy-L-tyrosine-p-nitorphenylester, and (d) a nonspecific substrate for a broad range of proteases: azocasein. Some physico-chemical characteristics of each enzymic reaction were studied. They were found to be distint enought to allow attributing each hydrolytic activity to a separate enzyme.