Sublethal effects of angling and release on golden perch Macquaria ambigua: implications for reproduction and fish health

The present study tested the hypothesis of no delayed sublethal effects of mild angling and release on the feeding, growth, somatic condition and gonadal development of golden perch Macquaria ambigua during gametogenesis. Subsamples of adult M. ambigua (n = 17–21 of 207), originally captured from the wild and stocked into ten 0·1 ha earthen ponds, were angled and released during early and late gametogenesis. Wild samples that were concurrently collected throughout the experiment underwent rapid and synchronous gonadal development and many spawned. While no spawning occurred in the ponds, most M. ambigua underwent normal gonadal development to maturity, including the angled fish. Angled fish also fed, maintained condition and actually grew faster than non‐angled captive controls. Although females that were angled during late gametogenesis more readily ingested and retained baited hooks, neither their subsequent condition nor gonadal development was significantly affected. The predominance of null results was attributed to the combined effects of the flexible reproductive strategy of M. ambigua, the benignness of mouth hooking and immediate release, and possible methodological issues arising from differential hooking success of more aggressive and resilient individuals. The findings support earlier catch‐and‐release research, but contrast with reports of acute reproductive effects following capture and handling for aquaculture broodstock. This discrepancy highlights the need for research to specifically address welfare questions relevant to recreational fisheries across various species and angling scenarios.     

Seed morphology,presence of areoles and water entry at imbibition of <i>Vicia dasycarpa</i> Ten. cv. Tolse F.C.A

The morphological characteristics of the seeds of Vicia dasycarpa Ten. cv. Tolse FCA were studied in relation to the area of imbibition water entry and were considered the presence of areoles. Seeds were analyzed using a stereo, optical and scanning electron microscope (SEM). The determination of the initial water entry area was carried out by immersing the seeds in a solution of tetrazolium (1%). This study showed that this species has seeds with a halo framing the hilum, an inconspicuous dry aril and a deltoid micropyle. The seedcoat pattern is papillose. The tracheid bar is surrounded by a ring of parenchymatous cells, and the tracheids show slight warty and non-vestured pits. It was confirmed the presence of an endospermic radicle pocket that surrounds and protect the radical tip. Two pairs of cotyledonar areoles were identified. It was established that the entry of water during imbibition starts in the area of the lens -having cracks- and moves in the sagittal plane. Both citological characteristic of tracheid bar and areoles presence show an apomorfous state between the Papiplionoids.     

A simple method for studying whole sections of rice grain

We developed a new and simple method to collect sections of a whole brown rice kernel for investigation of histological properties. A single kernel of rice was dehydrated through a graded ethanol series, transferred to xylene, and embedded in paraffin. During sectioning of the blocks using a rotary microtome, we used a special adhesive tape to collect and place the sections on slides so they remained flat. The use of the adhesive tape technique combined with autofluorescence characteristics allowed us to visualize cell walls throughout an entire longitudinal or transverse section of a whole rice kernel. We obtained scanning electron microscopy images of the sections to determine section quality.     

Staphylococcus aureus and Wegener's granulomatosis

Wegener's granulomatosis (WG) is a form of systemic vasculitis. It is characterized by granulomatous inflammation in the upper and lower airways, vasculitis and necrotizing glomerulonephritis, and is strongly associated with antineutrophil cytoplasmic antibodies against proteinase 3. Since the etiology of the disease is not clear, treatment, consisting of corticosteroids and immunosuppressives, is nonspecific and associated with severe side effects. Pinpointing the trigger(s) of the disease would highly improve treatment. Clinical evidence shows that an infectious agent, the bacterium Staphylococcus aureus, is a risk factor for disease relapse, suggesting its involvement in the pathogenesis of WG. Here we review both clinical and experimental data that either indicate or support a role for S. aureus in WG.     

Autoantibodies directed to novel components of the PM/Scl complex, the human exosome

The autoantigenic polymyositis/scleroderma (PM/Scl) complex was recently shown to be the human homologue of the yeast exosome, which is an RNA-processing complex. Our aim was to assess whether, in addition to targeting the known autoantigens PM/Scl-100 and PM/Scl-75, autoantibodies also target recently identified components of the PM/Scl complex. The prevalence of autoantibodies directed to six novel human exosome components (hRrp4p, hRrp40p, hRrp41p, hRrp42p, hRrp46p, hCsl4p) was determined in sera from patients with idiopathic inflammatory myopathy (n = 48), scleroderma (n = 11), or the PM/Scl overlap syndrome (n = 10). The sera were analyzed by enzyme-linked immunosorbent assays and western blotting using the affinity-purified recombinant proteins. Our results show that each human exosome component is recognized by autoantibodies. The hRrp4p and hRrp42p components were most frequently targeted. The presence of autoantibodies directed to the novel components of the human exosome was correlated with the presence of the anti-PM/Scl-100 autoantibody in the sera of patients with idiopathic inflammatory myopathy (IIM), as was previously found for the anti-PM/Scl-75 autoantibody. Other clear associations between autoantibody activities were not found. These results further support the conception that the autoimmune response may initially be directed to PM/Scl-100, whereas intermolecular epitope spreading may have caused the autoantibody response directed to the associated components.     

The merits of artificial selection for the development of restoration‐ready plant materials of native perennial grasses

Although seed harvested from remnant, wildland perennial‐grass populations can be used for restoration in humid and subhumid temperate regions, seed harvested in semiarid and arid environments is often of low quality and highly variable in quantity. In addition, ongoing harvest of indigenous populations can be unsustainable, especially for those that are small. In such environments, dependable and repeatable broad‐scale restoration of degraded grasslands requires sufficient and consistent supplies of reliable, cost‐effective seed sources that can only result from intensively managed cultivated stands. But does the harvest of intensively managed seed‐production fields inadvertently compromise genetic diversity, thereby adversely affecting the restoration outcome? That is, are seed‐production systems a part of the solution for restoration, or do they create new unintended management issues? This article discusses the potential impacts of cultivated seed‐production systems and recurrent artificial selection for specific traits on genetic integrity and performance of native‐species perennial‐grass populations. Although genetic shift resulting from cultivated perennial‐grass seed production may be inevitable, genetic shifts that change phenological expression may be limited in genotypes that exhibit high seed retention. Artificial selection can improve plant material performance on the often‐harsh conditions of restoration sites, but sufficiently high‐effective population sizes (N_e) must be maintained to conserve genetic diversity, thereby precluding the inbreeding depression that can compromise plant performance. Potentially useful traits of native perennial‐grass species that respond to artificial selection include seed production, seed retention, seedling establishment, competitive ability against weeds, and herbicide tolerance. Potential trade‐offs between traits should also be considered to avoid undesirable inadvertent responses to selection.     

Two mutations in the HMG-box with very different structural consequences provide insights into the nature of binding to four-way junction DNA.

Mutation of the highly conserved tryptophan residue in the A-domain HMG-box of HMG1 largely, but not completely, destroys the protein tertiary structure and abolishes its supercoiling ability, but does not abolish structure-specific DNA binding to four-way junctions. Circular dichroism shows that the protein has some residual alpha-helix (< 10%) and does not re-fold in the presence of DNA. Structure-specific DNA binding might therefore be a property of some primary structure element, for example the N-terminal extended strand, which even in the unfolded protein would be held in a restricted conformation by two, largely trans, X-Pro peptide bonds. However, mutation of P5 or P8 of the A-domain to alanine does not abolish the formation of the (first) complex in a gel retardation assay, which probably arises from binding to the junction cross-over, although the P8 mutation does affect the formation of higher complexes which may arise from binding to the junction arms. Since mutation of P8 in the W49R mutant has no effect on structure-specific junction binding, we propose that some residual alpha-helix in the protein might be involved, implicating this element in the interactions of HMG-boxes generally with DNA.     

Discrimination of modes of action of antifungal substances by use of metabolic footprinting

Diploid cells of Saccharomyces cerevisiae were grown under controlled conditions with a Bioscreen instrument, which permitted the essentially continuous registration of their growth via optical density measurements. Some cultures were exposed to concentrations of a number of antifungal substances with different targets or modes of action (sterol biosynthesis, respiratory chain, amino acid synthesis, and the uncoupler). Culture supernatants were taken and analyzed for their "metabolic footprints" by using direct-injection mass spectrometry. Discriminant function analysis and hierarchical cluster analysis allowed these antifungal compounds to be distinguished and classified according to their modes of action. Genetic programming, a rule-evolving machine learning strategy, allowed respiratory inhibitors to be discriminated from others by using just two masses. Metabolic footprinting thus represents a rapid, convenient, and information-rich method for classifying the modes of action of antifungal substances.     

Interaction of the E2 and E3 components of the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus. Use of a truncated protein domain in NMR spectroscopy

A (15)N-labelled peripheral-subunit binding domain (PSBD) of the dihydrolipoyl acetyltransferase (E2p) and the dimer of a solubilized interface domain (E3int) derived from the dihydrolipoyl dehydrogenase (E3) were used to investigate the basis of the interaction of E2p with E3 in the assembly of the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus. Thirteen of the 55 amino acids in the PSBD show significant changes in either or both of the (15)N and (1)H amide chemical shifts when the PSBD forms a 1 : 1 complex with E3int. All of the 13 amino acids reside near the N-terminus of helix I of PSBD or in the loop region between helix II and helix III. (15)N backbone dynamics experiments on PSBD indicate that the structured region extends from Val129 to Ala168, with limited structure present in residues Asn126 to Arg128. The presence of structure in the region before helix I was confirmed by a refinement of the NMR structure of uncomplexed PSBD. Comparison of the crystal structure of the PSBD bound to E3 with the solution structure of uncomplexed PSBD described here indicates that the PSBD undergoes almost no conformational change upon binding to E3. These studies exemplify and validate the novel use of a solubilized, truncated protein domain in overcoming the limitations of high molecular mass on NMR spectroscopy.     

Restoring grassy woodland diversity through direct seeding: Insights from six ‘best‐practice’ case studies in southern Australia

Ecological restoration of grassy woodland ecosystems is now a significant landscape‐scale conservation objective throughout southern Australia. Technological improvements in direct seeding are now sufficiently well‐advanced to examine whether cost‐effective restoration of grassy woodlands is feasible. Consideration of six ‘best practice case studies shows substantial evidence of success. Further refinement of direct seeding techniques, in combination with native seed production systems, however, will be required into the future to meet the scale of woodland conservation targets and restore ecological function.