Alleviation of metal stress by Pseudomonas orientalis and Chaetomium cupreum strains and their effects on Eucalyptus globulus growth promotion

Plant and Soil - More sustainable agricultural systems, which contribute to C sequestration and biological N fixation, require accurate quantification of plant C and N inputs into soils. This has...     

Cercopithecine and Colobine Abundance Across Protected and Unprotected Land in the Greater Mahale Ecosystem,Western Tanzania

International Journal of Primatology - Most primates live in unprotected land where abundances and threats may differ from those in protected areas. We therefore need to establish population...     

Microbiota of Telenomus tridentatus (Platygastroidea: Scelionidae): An unwanted parasitoid

The microbiota of Hymenoptera is limited to certain bacterial species that vary according to the habitat and diet; however, the bacterial populations are not known in Telenomus tridentatus Johnson & Bin, an egg parasitoid of agricultural importance. We determined the microbiota composition of adults of T. tridentatus using next‐generation sequencing technologies. We found the presence of the Phylums Proteobacteria, in greater proportion followed by Actinobacteria and Firmicutes, respectively. The most abundant species were Cutibacterium acnes, Aquabacterium sp. and Massilia sp. The results of this study could lead to investigating the importance of symbiotic bacteria in T. tridentatus and its relation with agricultural plantations.     

Conformational dynamics in loop swap mutants of homologous fibronectin type III domains

Fibronectin type III (FN-III) domains are autonomously folded modules found in a variety of multidomain proteins. The 10th FN-III domain from fibronectin (fnFN10) and the 3rd FN-III domain from tenascin-C (tnFN3) have 27% sequence identity and the same overall fold; however, the CC' loop has a different pattern of backbone hydrogen bonds and the FG loop is longer in fnFN10 compared to tnFN3. To examine the influence of length, sequence, and context in determining dynamical properties of loops, CC' and FG loops were swapped between fnFN10 and tnFN3 to generate four mutant proteins and backbone conformational dynamics on ps-ns and mus-ms timescales were characterized by solution (15)N-NMR spin relaxation spectroscopy. The grafted loops do not strongly perturb the properties of the protein scaffold; however, specific effects of the mutations are observed for amino acids that are proximal in space to the sites of mutation. The amino acid sequence primarily dictates conformational dynamics when the wild-type and grafted loop have the same length, but both sequence and context contribute to conformational dynamics when the loop lengths differ. The results suggest that changes in conformational dynamics of mutant proteins must be considered in both theoretical studies and protein design efforts.     

Caterpillar regurgitant induces pore formation in plant membranes

Formation of channel-like pores in a plant membrane was induced within seconds after application of an aqueous solution containing regurgitant of the insect larvae Spodoptera littoralis. Gated pore currents recorded on the tonoplast of the Charophyte Chara corallina displayed conductances up to several hundred pS. A voltage-dependent gating reaction supports the assumption that pore-forming molecules have amphipathic properties. Regurgitant samples separated into masses smaller or larger than 3kDa were evaluated by patch-clamp and mass spectroscopy. Fractions containing peptides larger than 3kDa constituted pores of large conductances, peptides smaller than 3kDa constituted pores of small conductances. Peptide-free eluates did not constitute conducting pores, indicating that pore-forming components in regurgitant are membrane-spanning oligopeptides.     

Genetic relatedness of commensal strains of <Emphasis Type="Italic">Candida albicans</Emphasis> carried in the oral cavity of patients’ dental prosthesis users in Brazil

The aim of this study is to describe the degree of yeast-colonization in diabetic and hemodialysed-users of dental prostheses. Individuals (306) were examined using an oral rinse technique in order to evaluate the incidence of yeast-carriage, and genotype of C. albicans. Yeasts were isolated from 68.4% (91/133) individual’s dental prostheses users. Dental prostheses were found to be a significant factor for the yeast colonization (P < 0.05). Overall, the intensity of carriage was higher in diabetic patients as compared with health and hemodialysed individuals (P < 0.05). The isolation rates were: C. albicans (51.7%), C. parapsilosis (20.9%), C. tropicalis (14.3%), C. glabrata (6.6%), C. krusei (3.3%), C. rugosa (1.1%), and Pichia (Pichia ohmeri, 2.2%). Ready-To-Go RAPD Analysis Beads were used and primer OPJ 6 distinguished the C. albicans isolates found in prostheses users. All the isolates were grouped into 11 RAPD profiles in four main clusters and, the average S _AB for the entire collection of 47 C.␣albicans isolates were 0.779 ± 0.178. Over 85% of isolates had a similarity level higher than or equal to 0.8 reinforcing the idea that the use of dental prostheses, independently of the host’s clinical condition, probably provides the necessary conditions for these strains to gain a growth-specific advantage over others.     

Sleeping Parties and Nest Distribution of Chimpanzees in the Savanna Woodland, Ugalla, Tanzania

We conducted ecological studies of chimpanzees (Pan troglodytes) in the Ugalla area, western Tanzania. Ugalla is one of the driest habitats of chimpanzees and the Ugalla River is the eastern boundary of chimpanzee distribution. Most of Ugalla is occupied by savanna woodlands dominated by deciduous trees of Brachystegia and Julbernardia. Chimpanzees tended not to make nests in riverine forests in plains, but in small patchy forests dominated by Monopetalanthus richardsiae and valley forests dominated by Julbernardia unijugata on slopes in mountainous areas. We estimated population density of chimpanzees to be 7–9 × 10⁻² individuals/km² based on nest censuses, suggesting that 2–3 × 10² individuals inhabited the 3352 km² area of Ugalla. The size of the largest nest cluster (n=23) suggests that 1 unit group (community) comprised 30–35 individuals. In the daytime, chimpanzees formed small feeding parties (mean 2.0 individuals), but larger ones in the evening (mean 4.8 individuals and 5.2 individuals based on fresh nest clusters). The pattern might reduce the predation risk from large nocturnal carnivores such as lions and leopards. The sleeping sites may function as both a safe sleeping site and a meeting point for chimpanzees with a huge home range that may have difficulty in finding other members of their unit group.     

Immunolocalization of metallothioneins in different tissues of turbot (Scophthalmus maximus) exposed to Cd

Metallothioneins (MT) were localized by immunochemistry in different organs and cell compartments of turbot exposed to sublethal concentrations (100 ppb) of Cd for 7 days. The polyclonal rabbit anti-cod MT antibody (NIVA, Norway) applied herein exhibited positive cross-reactivity with turbot MTs. Immunoreactive MTs were localized in the branchial epithelium, in the liver and in the kidney of turbot. In Cd exposed fishes MTs were demonstrated mainly in branchial chloride cells (CC) and to a lesser extend in the area where progenitor cells are located and in the cells of the respiratory epithelium (secondary lamellae). A higher staining intensity for MTs was observed in CC of the interlamellar space of the main branchial epithelium in comparison with control CC. MT-staining was also observed in the chondroblasts of the cartilage and in the erythrocytes within blood vessels both in control and Cd-exposed specimens. MT immunoreaction was high in the liver hepatocytes and weak in the epithelium of the proximal portion of the kidney in exposed turbot. The tegument, spleen and muscle were devoid of any immunolabelling in both treatments. Ultrastructural studies at the transmission electron microscope revealed that Cd-induced MTs were mainly located in the cytoplasm of gill CC, the lysosomes and the cytoplasm of hepatocytes and in the basal labyrinth of kidney proximal nephrocytes. The differential localization/induction of MTs in different cell types described hereby suggests that the quantification of the specific expression of MT may be used in biomonitoring programs as a biomarker of Cd exposure in aquatic environments.     

Avian host composition,local speciation and dispersal drive the regional assembly of avian malaria parasites in South American birds

Identifying the ecological factors that shape parasite distributions remains a central goal in disease ecology. These factors include dispersal capability, environmental filters and geographic distance. Using 520 haemosporidian parasite genetic lineages recovered from 7,534 birds sampled across tropical and temperate South America, we tested (a) the latitudinal diversity gradient hypothesis and (b) the distance–decay relationship (decreasing proportion of shared species between communities with increasing geographic distance) for this host–parasite system. We then inferred the biogeographic processes influencing the diversity and distributions of this cosmopolitan group of parasites across South America. We found support for a latitudinal gradient in diversity for avian haemosporidian parasites, potentially mediated through higher avian host diversity towards the equator. Parasite similarity was correlated with climate similarity, geographic distance and host composition. Local diversification in Amazonian lineages followed by dispersal was the most frequent biogeographic events reconstructed for haemosporidian parasites. Combining macroecological patterns and biogeographic processes, our study reveals that haemosporidian parasites are capable of circumventing geographic barriers and dispersing across biomes, although constrained by environmental filtering. The contemporary diversity and distributions of haemosporidian parasites are mainly driven by historical (speciation) and ecological (dispersal) processes, whereas the parasite community assembly is largely governed by host composition and to a lesser extent by environmental conditions.