Changing the conformation state of cytochrome b558 initiates NADPH oxidase activation: MRP8/MRP14 regulation

Phagocyte NADPH oxidase generates O2. for defense mechanisms and cellular signaling. Myeloid-related proteins MRP8 and MRP14 of the S100 family are EF-hand calcium-binding proteins. MRP8 and MRP14 were co-isolated from neutrophils on an anti-p47phox matrix with oxidase cytosolic factors and identified by mass spectrometry. MRP8 and MRP14 are absent from Epstein-Barr virus-immortalized B lymphocytes, and, coincidentally, these cells display weak oxidase activity compared with neutrophils. MRP8/MRP14 that was purified from neutrophils enhanced oxidase turnover of B cells in vitro, suggesting that MRP8/MRP14 is involved in the activation process. This was confirmed ex vivo by co-transfection of Epstein-Barr virus-transformed B lymphocytes with genes encoding MRP8 and MRP14. In a semi-recombinant cell-free assay, recombinant MRP8/MRP14 increased the affinity of p67phox for cytochrome b558 synergistically with p47phox. Moreover, MRP8/MRP14 initiated oxidase activation on its own, through a calcium-dependent specific interaction with cytochrome b558 as shown by atomic force microscopy and a structure-function relationship investigation. The data suggest that the change of conformation in cytochrome b558, which initiates the electron transfer, can be mediated by effectors other than oxidase cytosolic factors p67phox and p47phox. Moreover, MRP8/MRP14 dimer behaves as a positive mediator of phagocyte NADPH oxidase regulation.     

Androgen receptors in coeliac ganglion in late pregnant rat

The ovarian function is controlled by endocrine factors and neural influence. In late pregnant rat, androstenedione, from the coeliac ganglion, has a luteotrophic effect in the ex vivo coeliac ganglion-superior ovarian nerve-ovary system. In this work we investigate the presence of androgen receptors in the coeliac ganglion of late pregnant rats by immunohistochemistry. We also explore, from a physiological point of view, the potential participation of these receptors in the androstenedione ganglionic action on progesterone release and metabolism, as well as on nitrites release in the ovary compartment. The coeliac ganglion was isolated after being fixed in situ and immunohistochemistry was performed. In the system, three experimental groups were used with the addition of (a) androstenedione, (b) flutamide, and (c) androstenedione plus flutamide in the ganglion compartment. Progesterone and nitrite concentrations were determined in the ovary compartment at different incubation times. Corpora lutea samples isolated at the end of incubation were used to determine the expressions and activities of the progesterone synthesis (3β-hydroxysteroid-dehydrogenase, 3β-HSD) and degradation (20α-hydroxysteroid-dehydrogenase, 20α-HSD) enzymes. Immunohistochemistry revealed cytoplasmatic androgen receptor immunoreactivity in neural somas in the coeliac ganglion. In the coeliac ganglion-superior ovarian nerve-ovary system, androstenedione addition increased 3β-HSD and decreased 20α-HSD, showed a tendency to decrease 20α-HSD expression, and increased nitrites release in relation to control. Androstenedione plus flutamide decreased progesterone and nitrites release in relation to the androstenedione group. This work demonstrates the presence of androgen receptors in neurons of celiac ganglion and provides evidence for the luteotrophic action of androstenedione via a neural pathway that may be mediated by these receptors.     

First record of the brachiopod Lingulella waptaensis with pedicle from the Middle Cambrian Burgess Shale

Pettersson Stolk, S., Holmer, L. E. and Caron, J ‐B. 2010. First record of the brachiopod Lingulella waptaensis with pedicle from the Middle Cambrian Burgess Shale. —Acta Zoologica (Stockholm) 91 : 150–162 The organophosphatic shells of linguloid brachiopods are a common component of normal Cambrian–Ordovician shelly assemblages. Preservation of linguloid soft‐part anatomy, however, is extremely rare, and restricted to a few species in Lower Cambrian Konservat Lagerstätten. Such remarkable occurrences provide unique insights into the biology and ecology of early linguloids that are not available from the study of shells alone. Based on its shells, Lingulella waptaensis Walcott, was originally described in 1924 from the Middle Cambrian Burgess Shale but despite the widespread occurrence of soft‐part preservation associated with fossils from the same levels, no preserved soft parts have been reported. Lingulella waptaensis is restudied herein based on 396 specimens collected by Royal Ontario Museum field parties from the Greater Phyllopod Bed (Walcott Quarry Shale Member, British Columbia). The new specimens, including three with exceptional preservation of the pedicle, were collected in situ in discrete obrution beds. Census counts show that L. waptaensis is rare but recurrent in the Greater Phyllopod Bed, suggesting that this species might have been generalist. The wrinkled pedicle protruded posteriorly between the valves, was composed of a central coelomic space, and was slender and flexible enough to be tightly folded, suggesting a thin chitinous cuticle and underlying muscular layers. The nearly circular shell and the long, slender and highly flexible pedicle suggest that L. waptaensis lived epifaunally, probably attached to the substrate. Vertical cross‐sections of the shells show that L. waptaensis possessed a virgose secondary layer, which has previously only been known from Devonian to Recent members of the Family Lingulidae.     

Pollen from tree and shrub taxa in the atmosphere of Caxias do Sul (Rio Grande do Sul, Brazil)

An aerobiological study has been carried out in the region of Caxias do Sul in southern Brazil. Pollen monitoring was performed from January 1, 2001 through to December 31, 2002. A total of 30,469 pollen grains were collected during this period, and 40 pollen types were identified; of these, 23,389 pollen grains, representing 29 pollen types, originated from tree and shrub taxa. The maximum pollen concentration was registered in August 2001 and October 2002. In the study area, the pollen type Mimosa scabrella (18.8%) was much more abundant than all of the pollen types from tree and shrub taxa, such as: Urticaceae (18.4%), Myrtaceae (10.2%), Cupressaceae (7.7%), Myrsine (4.8%), Sorocea (3.9%), Pinaceae (2.9%), Asteraceae (2.2%) and Ricinus (2.1%). These nine pollen types accounted for the largest pollen concentrations of all the tree and shrub taxa. The pollen types Carya, Melastomataceae, Mimosa scabrella, Myrsine and Sorocea are reported for the first time in an aerobiological study in Brazil.     

The physiological function of von Willebrand's factor depends on its tubular storage in endothelial Weibel-Palade bodies

Weibel-Palade bodies are the 1-5 microm long rod-shaped storage organelles of endothelial cells. We have investigated the determinants and functional significance of this shape. We find that the folding of the hemostatic protein von Willebrand's factor (VWF) into tubules underpins the rod-like shape of Weibel-Palade bodies. Further, while the propeptide and the N-terminal domains of mature VWF are sufficient to form tubules, their maintenance relies on a pH-dependent interaction between the two. We show that the tubular conformation of VWF is essential for a rapid unfurling of 100 microm long, platelet-catching VWF filaments when exposed to neutral pH after exocytosis in cell culture and in living blood vessels. If tubules are disassembled prior to exocytosis, then short or tangled filaments are released and platelet recruitment is reduced. Thus, a 100-fold compaction of VWF into tubules determines the unique shape of Weibel-Palade bodies and is critical to this protein's hemostatic function.     

Mate choice in lekking sage grouse revisited: the roles of vocal display, female site fidelity, and copying

In lekking sage grouse (Centrocercus urophasianus), femalesexhibit relatively unanimous mate choice for particular males,but a satisfactory explanation for this unanimity has been elusive.We present analyses of mating distributions from two leks over4 years that provide evidence for female choice based on differencesin vocal display performance of males, the locations at whichhens mated in the previous year, and the choices of other females(copying). The unanimity of female choice varied markedly amongleks and years in correlation with changes in the mean numbersof hens that mated at the same time and hence the opportunityto copy. The results confirm that hens assess phenotypic traitsof males directly but also indicate that the secondary tacticsof site fidelity and copying are often important componentsof female choice. The occurrence of these secondary tacticshas three implications: the variance in mating success amonglek males will be a poor predictor of the intensity of sexualselection on specific traits; female preferences may generatemore clustered dispersions of displaying males than predictedby hotspot settlement models; and direct assessment of malesby females may be difficult or costly, a conclusion that supportsadaptive models of sexual selection over a nonadaptive Fisherianprocess. [Behav Ecol 1991;2:165–180]     

Meta-performance evaluation of sustainability indicators

There are many different kinds of frameworks for evaluating environmental and sustainability performance at the organizational level (profit or not-for-profit, private or public), sectoral level (e.g. industry, transport, agriculture and tourism), and local, regional or country levels. Despite the diversity of methods and tools to measure sustainable development, indicators are one of the approaches most used. However, these tools do not usually include evaluation of the performance measurement instrument itself. The main objective of this research is to develop a conceptual framework to design and assess the effectiveness of the sustainability indicators themselves. To put the proposed tool into practice, a set of key good-practice factors and meta-performance evaluation indicators is proposed for adoption in a national case study—the national sustainable development indicators system, SIDS Portugal, and the usefulness of this methodology is demonstrated. This approach aims to evaluate how appropriate a set of sustainability indicators is and allow an evaluation of overall performance-monitoring activities and results. Stakeholder involvement is an essential component of the proposed framework. The tool developed could support continuous improvement in the performance of ongoing sustainability indicator initiatives, allowing greater guidance, objectivity and transparency in sustainability assessment processes.     

New evidence of floral elaiophores and characterization of the oil flowers in the subtribe Oncidiinae (Orchidaceae)

Elaiophores seems to be uncommon in Orchidaceae; however, the number of known species with floral oil glands has increased in recent years, principally in Oncidiinae. Oil rewards are used by bees of the tribes Centridini, Tapinotaspidini and Tetrapediini. Our aims were to identify the presence of elaiophores and to describe their structure in species of Gomesa, Grandiphyllum and Trichocentrum, and to compare our results with other studies of elaiophores in Oncidiinae. We selected a set of characters presumably associated with oil production in flowers of Oncidiinae, which were evaluated using a cluster analysis to identify different floral morphologies of the oil flowers. The correlation between morphological types of oil flowers and species of pollinators was examined. The cluster analysis distinguished two groups of species, one of them principally linked with pollination by bees of genus Centris and the other type associated to species of Paratetrapedia and Tetrapedia. The evaluation of these results into a phylogenetic framework of the Oncidiinae, adding more evidence that species of this subtribe with similar floral morphology associated with floral oil secretion arise in many independent clades, in parallel evolution with the oil-bee pollination.     

Optimized Binding of [35S]GTPγS to Gq-Like Proteins Stimulated with Dopamine D1-Like Receptor Agonists

Subtypes of dopamine D₁-like receptors are coupled through the G proteins Gs or Gq to stimulate either adenylate cyclase or phospholipase C signaling cascades. In the present study, we have uncovered the marked enhancement by sodium deoxycholate of D1-like agonist-stimulated [³⁵S]GTPS binding to Gq-like G proteins in brain membranes, and determined the optimal experimental conditions for assessing agonist effects on [³⁵S]GTPS binding in the presence of the detergent. Factors and their optimal levels that were found to significantly enhance the sensitivity and robustness of the agonist-stimulated [³⁵S]GTPS binding reaction include protein concentration at 40 g/ml, cationic concentrations of 120 mM Na⁺, 1.8 mM K⁺, and 20 mM Mg²⁺, a molar guanine nucleotide ratio of 100,000 GDP to [³⁵S]GTPS, the presence of 1 mM deoxycholate, and an overall incubation duration of 30–120 min. Under the optimized conditions, the D₁-like agonist SKF38393 induced potent and highly efficacious (up to 1000%) stimulation of [³⁵S]GTPS binding in membrane preparations from the striatum and other rat brain regions. In striatal membranes incubated with drug for 2 h, immunoprecipitation of the [³⁵S]GTPS-bound proteins with specific G antibodies showed that at least 70% of SKF38393-stimulated [³⁵S]GTPS binding was to Gq. The present reaction parameters are consistent with conditions previously found to support dopaminergic stimulation of phospholipase C-mediated signaling in brain slice preparations. These results imply that different but equally physiologically relevant conditions can be obtained under which subtypes of dopaminergic receptors may couple preferentially to Gs and the adenylate cyclase pathway or to Gq and the phospholipase C pathway.