The malate synthase of Paracoccidioides brasiliensis is a linked surface protein that behaves as an anchorless adhesin

Background  

The pathogenic fungus Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis (PCM). This is a pulmonary mycosis acquired by inhalation of fungal airborne propagules that can disseminate to several organs and tissues leading to a severe form of the disease. Adhesion and invasion to host cells are essential steps involved in the internalization and dissemination of pathogens. Inside the host, P. brasiliensis may use the glyoxylate cycle for intracellular survival.     

A family history of DUX4: phylogenetic analysis of DUXA, B, C and Duxbl reveals the ancestral DUX gene

Background  

DUX4 is causally involved in the molecular pathogenesis of the neuromuscular disorder facioscapulohumeral muscular dystrophy (FSHD). It has previously been proposed to have arisen by retrotransposition of DUXC, one of four known intron-containing DUX genes. Here, we investigate the evolutionary history of this multi-member double-homeobox gene family in eutherian mammals.     

Impact of moisture on in vitro germination of Metarhizium anisopliae and Beauveria bassiana and their activity on Triatoma infestans

The in vitro germination of 11 Metarhizium anisopliae and 11 Beauveria bassiana isolates originating from substrates collected in rural peridomestic areas in Central Brazil where triatomines are common was tested. Conidia completed germination up to 24 h after exposure to water activity of >0.99 a_w in all isolates tested. At lower 0.93 a_w germination was delayed but conidia of most isolates germinated at high rates (>98 %) within 216 h of incubation. Activities of 2 M. anisopliae and 2 B. bassiana isolates with different patterns of germination at 0.93 a_w were tested in Triatoma infestans third instar nymphs. There was no relationship between germination kinetics in vitro at 0.93 a_w and their activity in vivo at 98, 75 and 43 % relative humidity (rh). Isolates with accelerated germination at 0.93 a_w were not more virulent at 75 and 43 % rh compared with isolates with retarded or no germination. Highest mortalities were observed at 98 % rh, and they did not exceed 25 % after 25 d incubation at lower 75 and 43 % rh. Isolates that originated from a region with an extensive annual arid period showed no adaptation to lower humidity in their activity against T. infestans.     

Effect of iron on the expression of sirR and sitABC in biofilm-associated Staphylococcus epidermidis

Background  

Different gene expression patterns correlate with the altered phenotype in biofilm-associated bacteria. Iron and iron-linked genes are thought to play a key-role in biofilm formation. The expression of Fe-linked genes (sirR, sitABC operon) in Staphylococcus epidermidis, was compared in planktonic versus sessile bacteria in vitro and in vivo in a subcutaneous foreign body rat model.     

Multiple invasions of Gypsy and Micropia retroelements in genus Zaprionus and melanogaster subgroup of the genus Drosophila

Background  

The Zaprionus genus shares evolutionary features with the melanogaster subgroup, such as space and time of origin. Although little information about the transposable element content in the Zaprionus genus had been accumulated, some of their elements appear to be more closely related with those of the melanogaster subgroup, indicating that these two groups of species were involved in horizontal transfer events during their evolution. Among these elements, the Gypsy and the Micropia retroelements were chosen for screening in seven species of the two Zaprionus subgenera, Anaprionus and Zaprionus.     

Identification and characterization of the heme-binding proteins SeShp and SeHtsA of Streptococcus equi subspecies equi

Background  

Heme is a preferred iron source of bacterial pathogens. Streptococcus equi subspecies equi is a bacterial pathogen that causes strangles in horses. Whether S. equi has a heme acquisition transporter is unknown.     

Polyploid evolution in Oryza officinalis complex of the genus Oryza

Background  

Polyploidization is a prominent process in plant evolution, whereas the mechanism and tempo-spatial process remained poorly understood. Oryza officinalis complex, a polyploid complex in the genus Oryza, could exemplify the issues not only for it covering a variety of ploidy levels, but also for the pantropical geographic pattern of its polyploids in Asia, Africa, Australia and Americas, in which a pivotal genome, the C-genome, witnessed all the polyploidization process.     

Ds tagging of BRANCHED FLORETLESS 1 (BFL1) that mediates the transition from spikelet to floret meristem in rice (Oryza sativa L)

Background  

The genetics of spikelet formation, a feature unique to grasses such as rice and maize, is yet to be fully understood, although a number of meristem and organ identity mutants have been isolated and investigated in Arabidopsis and maize. Using a two-element Ac/Ds transposon tagging system we have isolated a rice mutant, designated branched floretless 1 (bfl1) which is defective in the transition from spikelet meristem to floret meristem.     

Metabolic fluxes in the central carbon metabolism of Dinoroseobacter shibae and Phaeobacter gallaeciensis, two members of the marine Roseobacter clade

Background  

In the present work the central carbon metabolism of Dinoroseobacter shibae and Phaeobacter gallaeciensis was studied at the level of metabolic fluxes. These two strains belong to the marine Roseobacter clade, a dominant bacterial group in various marine habitats, and represent surface-associated, biofilm-forming growth (P. gallaeciensis) and symbiotic growth with eukaryotic algae (D. shibae). Based on information from recently sequenced genomes, a rich repertoire of pathways has been identified in the carbon core metabolism of these organisms, but little is known about the actual contribution of the various reactions in vivo.     

Coordinated spatial and temporal expression ofHox genes during embryogenesis in the acoelConvolutriloba longifissura

Background  

Hox genes are critical for patterning the bilaterian anterior-posterior axis. The evolution of their clustered genomic arrangement and ancestral function has been debated since their discovery. As acoels appear to represent the sister group to the remaining Bilateria (Nephrozoa), investigatingHox gene expression will provide an insight into the ancestral features of theHox genes in metazoan evolution.     

Resistance to organic hydroperoxides requires ohr and ohrR genes in Sinorhizobium meliloti

Background  

Sinorhizobium meliloti is a symbiotic nitrogen-fixing bacterium that elicits nodules on roots of host plants Medicago sativa. During nodule formation bacteria have to withstand oxygen radicals produced by the plant. Resistance to H₂O₂ and superoxides has been extensively studied in S. meliloti. In contrast resistance to organic peroxides has not been investigated while S. meliloti genome encodes putative organic peroxidases. Organic peroxides are produced by plants and are highly toxic. The resistance to these oxygen radicals has been studied in various bacteria but never in plant nodulating bacteria.     

A dominant mutation (SAD) bypassing the requirement for the a mating type locus in yeast sporulation

Summary SAD (suppressor of a deficiencies) is a mutation that allows -mater diploids such as / or a1^-/ strains to sporulate. This mutation is unstable and reverts to wildtype (sad ⁺) even in strains homozygous for SAD. SAD is dominant to sad ⁺: / and a1^-/ sad ¹/SAD diploids are sporulation-proficient. SAD is located on chromosome III, 40 cM distal to the mating type locus, between THR4 and HMR a. The ability of SAD to support sporulation requires the presence of an mating type locus with an active 2 function. Possible models for the action of SAD are (1) SAD bypasses the need for a1 function in sporulation, and (2) SAD provides a1 function to MAT a1^- mutants by supplying a1 function itself, for example, by allowing expression of a silent copy of MAT a.     

Paracoccidioides brasiliensis pancreatic destruction in Calomys callosus experimentally infected

Background  

The wild rodent Calomys callosus is notably resistant to Trypanosoma cruzi infection. In order to better characterize this animal model for experimental infections, we inoculated C. callosus intraperitoneally with Paracoccidioides brasiliensis, a thermally dimorphic fungus that causes a chronic disease with severe granuloma formation in the mouse and humans. The dissemination of P. brasiliensis cells through the lungs, liver, pancreas, and spleen was assessed by histological analysis.     

Allelic diversity and phylogeny of homB, a novel co-virulence marker of Helicobacter pylori

Background  

The homB gene is a Helicobacter pylori disease-marker candidate, strongly associated with peptic ulcer disease, while homA, its paralogue gene with 90% sequence identity, is correlated with non-ulcer dyspepsia. The HomB encoded outer membrane protein was shown to contribute to the proinflammatory properties of H. pylori and also to be involved in bacterial adherence.     

Introgression of Swertia mussotii gene into Bupleurum scorzonerifolium via somatic hybridization

Background  

The wild herb Swertia mussotii is a source of the anti-hepatitis compounds swertiamarin, mangiferin and gentiopicroside. Its over-exploitation has raised the priority of producing these compounds heterologously. Somatic hybridization represents a novel approach for introgressing Swertia mussotii genes into a less endangered species.     

Improving Salmonella vector with rec mutation to stabilize the DNA cargoes

Background  

Salmonella has been employed to deliver therapeutic molecules against cancer and infectious diseases. As the carrier for target gene(s), the cargo plasmid should be stable in the bacterial vector. Plasmid recombination has been reduced in E. coli by mutating several genes including the recA, recE, recF and recJ. However, to our knowledge, there have been no published studies of the effect of these or any other genes that play a role in plasmid recombination in Salmonella enterica.     

A secreted serine protease of <Emphasis Type="Italic">Paracoccidioides brasiliensis</Emphasis> and its interactions with fungal proteins

Background  

Paracoccidioides brasiliensis is a thermodimorphic fungus, the causative agent of paracoccidioidomycosis (PCM). Serine proteases are widely distributed and this class of peptidase has been related to pathogenesis and nitrogen starvation in pathogenic fungi.     

Characterization of N -acylhomoserine lactone-degrading bacteria associated with the Zingiber officinale (ginger) rhizosphere: Co-existence of quorum quenching and quorum sensing in Acinetobacter and Burkholderia

Background  

Cell-to-cell communication (quorum sensing (QS)) co-ordinates bacterial behaviour at a population level. Consequently the behaviour of a natural multi-species community is likely to depend at least in part on co-existing QS and quorum quenching (QQ) activities. Here we sought to discover novel N -acylhomoserine lactone (AHL)-dependent QS and QQ strains by investigating a bacterial community associated with the rhizosphere of ginger (Zingiber officinale) growing in the Malaysian rainforest.