Diet-dependent life history,feeding preference and thermal requirements of the predatory mite <Emphasis Type="Italic">Neoseiulus baraki</Emphasis> (Acari: Phytoseiidae)

Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) has been reported from the Americas, Africa and Asia, often in association with Aceria guerreronis Keifer (Acari: Eriophyidae), one of the most important pests of coconut (Cocos nucifera L.) in different parts of the world. That phytoseiid has been considered one of the most common predators associated with A. guerreronis in Brazil. The objective of this study was to evaluate the feeding preference and the effect of food items commonly present on coconut fruits and several temperature regimes on the life history of a Brazilian population of N. baraki. Completion of immature development was possible when N. baraki was fed A. guerreronis, Steneotarsonemus concavuscutum Lofego and Gondim Jr., and Tyrophagus putrescentiae (Schrank). Fecundity was highest on T. putrescentiae (39.4 eggs), followed by A. guerreronis (24.8 eggs). In choice tests, irrespective of the food on which N. baraki was reared, a larger number of adults of this predator chose leaf discs containing A. guerreronis than discs containing other food items, demonstrating a preference of the former for the latter as food. Egg to adult thermal developmental time was calculated as 84.2 degree-days, above a threshold of 15.8°C. This lower developmental threshold is higher than previously published for phytoseiid species from higher latitudes. Neoseiulus baraki was shown to have higher biotic potential at 30°C (r _m 0.29). The results suggest N. baraki to be a promising biological control agent of A. guerreronis, well adapted to survive and develop in areas with relatively high temperatures, where that pest prevails.     

Structure of Brazilian Atlantic forests with occurrence of the woolly spider monkey (<Emphasis Type="Italic">Brachyteles hypoxanthus</Emphasis>)

This work examines patches of Atlantic forests in Minas Gerais State where woolly spider monkeys (Brachyteles hypoxanthus) are inhabitants in order to understand the effects of forest structure, diversity, and succession in B. hypoxanthus abundance. This study was carried out in three reserves: Rio Doce State Park (PERD), Mata do Sossego (Sossego), and Serra do Brigadeiro State Park (PESB). Structural studies were carried out by means of point-centered quarter samples in areas used by woolly spider monkeys. Evenness was lower in PERD than in the other two communities. By means of successional functional groups analysis and diametric structure, the PERD forest sample was shown to be in the later, and PESB forest sample in the earlier, stages of secondary succession. We found that tree species evenness and structural traits driven by succession were important factors in determining spider monkey abundance patterns. The PERD forest sample had lower evenness and had lower density of woolly spider monkeys than the Sossego forest sample. The lowest density of these primates was in the PESB forest sample, the earlier successional stage of secondary succession of this study.     

Antinociceptive activity of atranorin in mice orofacial nociception tests

Physicochemical characterization and antinociceptive and anti-inflammatory activities of atranorin (AT) extracted from Cladina kalbii Ahti in formalin- and capsaicin-induced orofacial pain and anti-inflammatory tests in rodents were studied. Physicochemical characterization showed that AT has the general formula C19H18O8. Male Swiss mice were pretreated with AT (100, 200, and 400 mg/kg, i.p.), morphine (3 mg/kg, i.p.), or vehicle (0.9% saline with two drops of 0.2% Tween 80) before formalin (20 microl, 2%) or capsaicin (20 microl, 2.5 microg) were injected into the right vibrissa. Our results showed that i.p. treatment with AT displayed marked inhibitory effects in different orofacial pain tests in mice. AT (400 mg/kg, i.p.) was effective in reducing the nociceptive face-rubbing behavioural response in both phases of the formalin test, which was also naloxone-sensitive. Additionally, AT produced a significant antinociceptive effect at all doses in the capsaicin test. Such results were unlikely to be provoked by motor abnormality, since AT-treated mice exhibited no performance alteration on the rota rod apparatus. AT exhibited significant anti-inflammatory activity in the acute model of inflammation (leukocyte migration to the peritoneal cavity), carrageenan- and arachidonic acid-induced hind paw edema in rats. Additionally, AT exhibited a dose-dependent antioxidant activity in vitro, as assessed by total radical-trapping antioxidant parameter and total antioxidant reactivity assays. All these findings suggest that AT might represent an important tool for the management of orofacial pain and/or inflammatory disorders.     

Intra‐ and interspecific divergence in the nuclear sequences of the clock gene period in species of the Drosophila buzzatii cluster

We have measured nucleotide variation in the CLOCK/CYCLE heterodimer inhibition domain (CCID) of the clock X‐linked gene period in seven species belonging to the Drosophila buzzatii cluster, namely D. buzzatii, Drosophila koepferae, Drosophila antonietae, Drosophila serido, Drosophila gouveai, Drosophila seriema and Drosophila borborema. We detected that the purifying selection is the main force driving the sequence evolution in period, in agreement with the important role of CCID in clock machinery. Our survey revealed that period provides valuable phylogenetic information that allowed to resolve phylogenetic relationships among D. gouveai, D. borborema and D. seriema, which composed a polytomic clade in preliminary studies. The analysis of patterns of intraspecific variation revealed two different lineages of period in D. koepferae, probably reflecting introgressive hybridization from D. buzzatii, in concordance with previous molecular data.     

Ion channels in volume regulation of clonal kidney cells

Objectives: Clonal kidney cells (Vero cells) are extensively utilized in the manufacture of biological preparations for disease diagnostics and therapeutics and also in preparation of vaccines. In all cells, regulation of volume is an essential function coupled to a variety of physiological processes and is a topic of interest. The objective here was to investigate involvement of ion channels in the process of volume regulation of Vero cells. Methods: Involvement of ion channels in cell volume regulation was studied using video‐microscopy and flow cytometry. Pharmacologically unaltered cells of different sizes, which are presumably at different phases of the cell cycle, were used. Results: Ion transport inhibitors altered all phases of regulatory volume decrease (RVD) of Vero cells, rate of initial cell swelling, V_max and volume recovery. Effects were dependent on type of inhibitor and on cell size (cell cycle phase). Participation of aquaporins in RVD was suggested. Inhibitors decelerated growth, arresting Vero cells at the G₀/G₁ phase boundary. Electrophysiological study confirmed presence of volume‐activated Cl^? channels and K⁺ channels in plasmatic membranes of the cells. Conclusion: Vero cells of all sizes maintained the ability to recover from osmotic swelling. Activity of ion channels was one of the key factors that controlled volume regulation and proliferation of the cells.     

Stereological and allometric studies on neurons and axo-dendritic synapses in the superior cervical ganglia of rats, capybaras and horses

The superior cervical ganglion (SCG) in mammals varies in structure according to developmental age, body size, gender, lateral asymmetry, the size and nuclear content of neurons and the complexity and synaptic coverage of their dendritic trees. In small and medium-sized mammals, neuron number and size increase from birth to adulthood and, in phylogenetic studies, vary with body size. However, recent studies on larger animals suggest that body weight does not, in general, accurately predict neuron number. We have applied design-based stereological tools at the light-microscopic level to assess the volumetric composition of ganglia and to estimate the numbers and sizes of neurons in SCGs from rats, capybaras and horses. Using transmission electron microscopy, we have obtained design-based estimates of the surface coverage of dendrites by postsynaptic apposition zones and model-based estimates of the numbers and sizes of synaptophysin-labelled axo-dendritic synaptic disks. Linear regression analysis of log-transformed data has been undertaken in order to establish the nature of the relationships between numbers and SCG volume (V_scg). For SCGs (five per species), the allometric relationship for neuron number (N) is N=35,067×V_scg^0.781 and that for synapses is N=20,095,000×V_scg^1.328, the former being a good predictor and the latter a poor predictor of synapse number. Our findings thus reveal the nature of SCG growth in terms of its main ingredients (neurons, neuropil, blood vessels) and show that larger mammals have SCG neurons exhibiting more complex arborizations and greater numbers of axo-dendritic synapses.     

<Emphasis Type="Italic">Crassostrea gigas</Emphasis> in natural oyster banks in southern Brazil

We report on the invasion of Brazil by the Pacific oyster Crassostrea gigas, and discuss the likely routes of invasion. Because this phenotypically diverse oyster sometimes resembles the native species C. brasiliana and C. rhizophorae, its invasion went unnoticed until it was detected through the analysis of DNA sequences for ribosomal 16S and the ribosomal second internal transcribed spacer. C. gigas was found amongst the native species in oyster banks up to 100 km south of oyster farms in South Brazil. Under most circumstances, water temperatures in the coastal southerly Brazil current would be too high to allow for the establishment of stable populations of C. gigas, but the production of spat in oyster farm laboratories has probably selected for resistance to warmer temperatures, which would promote invasion by C. gigas.     

Molecular identification, phylogeny and geographic distribution of Brazilian mangrove oysters (Crassostrea)

Oysters (Ostreidae) manifest a high degree of phenotypic plasticity, whereby morphology is of limited value for species identification and taxonomy. By using molecular data, the aim was to genetically characterize the species of Crassostrea occurring along the Brazilian coast, and phylogenetically relate these to other Crassostrea from different parts of the world. Sequencing of the partial cytochrome oxidase c subunit I gene (COI), revealed a total of three species of Crassostrea at 16 locations along the Brazilian coast. C. gasar was found from Curuçá (Pará state) to Santos (São Paulo state), and C. rhizophorae from Fortim (Ceará state) to Florianópolis (Santa Catarina state), although small individuals of the latter species were also found at Ajuruteua beach (municipality of Bragança, Pará state). An unidentified Crassostrea species was found only on Canela Island, Bragança. Crassostrea gasar and C. rhizophorae grouped with C. virginica, thereby forming a monophyletic Atlantic group, whereas Crassostrea sp. from Canela Island was shown to be more similar to Indo-Pacific oysters, and either arrived in the Atlantic Ocean before the convergence of the Isthmus of Panama or was accidentally brought to Brazil by ship.     

A new topology of ACBP from Moniliophthora perniciosa

Acyl-CoA binding protein (ACBP) is a housekeeping protein and is an essential protein in human cell lines and in Trypanosoma brucei. The ACBP of Moniliophthora perniciosa is composed of 104 amino acids and is possibly a non-classic isoform exclusively from Basidiomycetes. The M. perniciosa acbp gene was cloned, and the protein was expressed and purified. Acyl-CoA ester binding was analyzed by isoelectric focusing, native gel electrophoresis and isothermal titration calorimetry. Our results suggest an increasing affinity of ACBP for longer acyl-CoA esters, such as myristoyl-CoA to arachidoyl-CoA, and best fit modeling indicates two binding sites. ACBP undergoes a shift from a monomeric to a dimeric state, as shown by dynamic light scattering, fluorescence anisotropy and native gel electrophoresis in the absence and presence of the ligand. The protein's structure was determined at 1.6 Å resolution and revealed a new topology for ACBP, containing five α-helices instead of four. α-helices 1, 2, 3 and 4 adopted a bundled arrangement that is unique from the previously determined four-helix folds of ACBP, while α-helices 1, 2, 4 and 5 formed a classical four-helix bundle. A MES molecule was found in the CoA binding site, suggesting that the CoA site could be a target for small compound screening.