The mitogenome of Onchocerca volvulus from the Brazilian Amazonia focus

We report here the first complete mitochondria genome of Onchocerca volvulus from a focus outside of Africa. An O. volvulus mitogenome from the Brazilian Amazonia focus was obtained using a combination of high-throughput and Sanger sequencing technologies. Comparisons made between this mitochondrial genome and publicly available mitochondrial sequences identified 46 variant nucleotide positions and suggested that our Brazilian mitogenome is more closely related to Cameroon-origin mitochondria than West African-origin mitochondria. As well as providing insights into the origins of Latin American onchocerciasis, the Brazilian Amazonia focus mitogenome may also have value as an epidemiological resource.     

Hindcasting cyanobacterial communities in Lake Okaro with germination experiments and genetic analyses

Cyanobacterial blooms are becoming increasingly prevalent worldwide. Sparse historic phytoplankton records often result in uncertainty as to whether bloom-forming species have always been present and are proliferating in response to eutrophication or climate change, or if there has been a succession of new arrivals through recent history. This study evaluated the relative efficacies of germination experiments and automated rRNA intergenic spacer analysis (ARISA) assays in identifying cyanobacteria in a sediment core and thus reconstructing the historical composition of cyanobacterial communities. A core (360 mm in depth) was taken in the central, undisturbed basin of Lake Okaro, New Zealand, a lake with a rapid advance of eutrophication and increasing cyanobacteria populations. The core incorporated a tephra from an 1886 volcanic eruption that served to delineate recent sediment deposition. ARISA and germination experiments successfully detected akinete-forming nostocaleans in sediment dating 120 bp and showed little change in Nostocales species structure over this time scale. Species that had not previously been documented in the lake were identified including Aphanizomenon issatschenkoi , a potent anatoxin-a producer. The historic composition of Chrococcales and Oscillatoriales was more difficult to reconstruct, potentially due to the relatively rapid degradation of vegetative cells within sediment.     

The complete genome of Bacillus amyloliquefaciens subsp. plantarum CAU B946 contains a gene cluster for nonribosomal synthesis of iturin A

The genome of the rhizobacterium Bacillus amyloliquefaciens subsp. plantarum CAU B946 was 4.02 Mb in size and harbored 3,823 genes (coding sequences [CDS]). Nine giant gene clusters were dedicated to nonribosomal synthesis of antimicrobial compounds. Remarkably, strain CAU B946 possessed a gene cluster involved in synthesis of iturin A.     

Imaging taste responses in the fly brain reveals a functional map of taste category and behavior

The sense of taste allows animals to distinguish nutritious and toxic substances and elicits food acceptance or avoidance behaviors. In Drosophila, taste cells that contain the Gr5a receptor are necessary for acceptance behavior, and cells with the Gr66a receptor are necessary for avoidance. To determine the cellular substrates of taste behaviors, we monitored taste cell activity in vivo with the genetically encoded calcium indicator G-CaMP. These studies reveal that Gr5a cells selectively respond to sugars and Gr66a cells to bitter compounds. Flies are attracted to sugars and avoid bitter substances, suggesting that Gr5a cell activity is sufficient to mediate acceptance behavior and that Gr66a cell activation mediates avoidance. As a direct test of this hypothesis, we inducibly activated different taste neurons by expression of an exogenous ligand-gated ion channel and found that cellular activity is sufficient to drive taste behaviors. These studies demonstrate that taste cells are tuned by taste category and are hardwired to taste behaviors.     

Proteomic profile of culture filtrate from the Brazilian vaccine strain <Emphasis Type="Italic">Mycobacterium bovis</Emphasis> BCG Moreau compared to <Emphasis Type="Italic">M. bovis</Emphasis> BCG Pasteur

Background  

Bacille Calmette-Guerin (BCG) is currently the only available vaccine against tuberculosis (TB) and comprises a heterogeneous family of sub-strains with genotypic and phenotypic differences. The World Health Organization (WHO) affirms that the characterization of BCG sub-strains, both on genomic and proteomic levels, is crucial for a better comprehension of the vaccine. In addition, these studies can contribute in the development of a more efficient vaccine against TB. Here, we combine two-dimensional electrophoresis (2DE) and mass spectrometry to analyse the proteomic profile of culture filtrate proteins (CFPs) from M. bovis BCG Moreau, the Brazilian vaccine strain, comparing it to that of BCG Pasteur. CFPs are considered of great importance given their dominant immunogenicity and role in pathogenesis, being available for interaction with host cells since early infection.     

Identification of a divergent environmental DNA sequence clade using the phylogeny of gregarine parasites (Apicomplexa) from crustacean hosts

Background

Environmental SSU rDNA surveys have significantly improved our understanding of microeukaryotic diversity. Many of the sequences acquired using this approach are closely related to lineages previously characterized at both morphological and molecular levels, making interpretation of these data relatively straightforward. Some sequences, by contrast, appear to be phylogenetic orphans and are sometimes inferred to represent “novel lineages” of unknown cellular identity. Consequently, interpretation of environmental DNA surveys of cellular diversity rely on an adequately comprehensive database of DNA sequences derived from identified species. Several major taxa of microeukaryotes, however, are still very poorly represented in these databases, and this is especially true for diverse groups of single-celled parasites, such as gregarine apicomplexans.

Methodology/Principal Findings

This study attempts to address this paucity of DNA sequence data by characterizing four different gregarine species, isolated from the intestines of crustaceans, at both morphological and molecular levels: Thiriotia pugettiae sp. n. from the graceful kelp crab (Pugettia gracilis), Cephaloidophora cf. communis from two different species of barnacles (Balanus glandula and B. balanus), Heliospora cf. longissima from two different species of freshwater amphipods (Eulimnogammarus verrucosus and E. vittatus), and Heliospora caprellae comb. n. from a skeleton shrimp (Caprella alaskana). SSU rDNA sequences were acquired from isolates of these gregarine species and added to a global apicomplexan alignment containing all major groups of gregarines characterized so far. Molecular phylogenetic analyses of these data demonstrated that all of the gregarines collected from crustacean hosts formed a very strongly supported clade with 48 previously unidentified environmental DNA sequences.

Conclusions/Significance

This expanded molecular phylogenetic context enabled us to establish a major clade of intestinal gregarine parasites and infer the cellular identities of several previously unidentified environmental SSU rDNA sequences, including several sequences that have formerly been discussed broadly in the literature as a suspected “novel” lineage of eukaryotes.     

The hinge region of the scaffolding protein of cell contacts, zonula occludens protein 1, regulates interacting with various signaling proteins

Zonula occludens protein 1 (ZO-1) is a ubiquitous scaffolding protein, but it is unknown why it functions in very different cellular contacts. We hypothesized that a specific segment, the unique hinge region, can be bound by very different regulatory proteins. Using surface plasmon resonance spectroscopy and binding assays to peptide libraries, we show, for the first time, that the hinge region directly interacts with disparate signal elements such as G-proteins alpha 12 and alpha i2, the regulator of G-protein signaling 5, multifunctional signaling protein ahnak1, and L-type Ca2+-channel beta-2-subunit. The novel binding proteins specifically bound to a coiled coil-helix predicted in the hinge region of ZO-. The interactions were modulated by phosphorylation in the hinge helix. Activation of the G-proteins influenced their association to ZO-1. In colon cells, G alpha i2 and ZO-1 were associated, as shown by coimmunoprecipitation. After cotransfection in kidney cells, G alpha i2 barely colocalized with ZO-1; the colocalization coefficient was significantly increased when epinephrine activated G-protein signaling. In conclusion, proteins with different regulatory potential adhere to and influence cellular functions of ZO-proteins, and the interactions can be modulated via its hinge region and/or the binding proteins.     

Testing the Sensitivity of Tract-Based Spatial Statistics to Simulated Treatment Effects in Preterm Neonates

Early neuroimaging may provide a surrogate marker for brain development and outcome after preterm birth. Tract-Based Spatial Statistics (TBSS) is an advanced Diffusion Tensor Image (DTI) analysis technique that is sensitive to the effects of prematurity and may provide a quantitative marker for neuroprotection following perinatal brain injury or preterm birth. Here, we test the sensitivity of TBSS to detect diffuse microstructural differences in the developing white matter of preterm infants at term-equivalent age by modelling a ‘treatment’ effect as a global increase in fractional anisotropy (FA). As proof of concept we compare these simulations to a real effect of increasing age at scan. 3-Tesla, 15-direction diffusion tensor imaging (DTI) was acquired from 90 preterm infants at term-equivalent age. Datasets were randomly assigned to ‘treated’ or ‘untreated’ groups of increasing size and voxel-wise increases in FA were used to simulate global treatment effects of increasing magnitude in all ‘treated’ maps. ‘Treated’ and ‘untreated’ FA maps were compared using TBSS. Predictions from simulated data were then compared to exemplar TBSS group comparisons based on increasing postmenstrual age at scan. TBSS proved sensitive to global differences in FA within a clinically relevant range, even in relatively small group sizes, and simulated data were shown to predict well a true biological effect of increasing age on white matter development. These data confirm that TBSS is a sensitive tool for detecting global group-wise differences in FA in this population.