Molecular markers reveal diversity in composition of Megastigmus (Hymenoptera: Megastigmidae) from eucalypt galls

Since outbreaks of the invasive blue gum chalcids Leptocybe spp. began, the genus Megastigmus (Hymenoptera: Megastigmidae) has been increasingly studied as containing potential biocontrol agents against these pests. Megastigmus species have been collected and described from Australia, the presumed origin of Leptocybe spp., with M. zvimendeli and M. lawsoni reported as Leptocybe spp. parasitoids established outside of Australia. Parasitic Megastigmus have been reported to occur locally in the Neotropics, Afrotropic, Palearctic, and Indomalaya biogeographic realms, and in many cases described as new to science. However, molecular tools have not been used in studying parasitic Megastigmus, and difficulties in morphological taxonomy have compromised further understanding of eucalypt-associated Megastigmus as well as the Megastigmus-Leptocybe association. In this study, we used molecular markers to study the species composition and phylogeny of Megastigmus collected from eucalypt galls in Australia and from Leptocybe spp. galls from South Africa, Kenya, Israel, China, and Vietnam. We record thirteen discrete species and a species complex associated with eucalypt galls. A summary of morphological characters is provided to assist morphological delimitation of the studied group. A phylogeny based on 28S rDNA identified species groups of importance to Leptocybe spp. biocontrol agents from four clades with nine species. Relationships between Megastigmus from eucalypt galls and their phytophagous congeners were unresolved. Further molecular work is needed to clarify the identity of many species

Anti-fibrotic potential of Tomentosenol A, a constituent of cerumen from the Australian native stingless bee, Tetragonula carbonaria

Bioactivity-guided fractionation was used to isolate two compounds, tomentosenol A (1) and torellianone A (2), from a cerumen extract from Tetragonula carbonaria. The anti-fibrotic activity of these compounds was examined using human cultured neonatal foreskin fibroblasts (NFF) and immortalised keratinocytes (HaCaTs). Tomentosenol A (1), inhibited NFF and HaCaT cell proliferation and prevented NFF and HaCaT scratch wound repopulation at 12.5−25 µM concentrations. These inhibitory effects were associated with reduced cell viability, determined by tetrazolium dye (MTT) and sulforhodamine B (SRB) assays. Compound 1 further inhibited transforming growth factor-β1 (TGF-β1)-stimulated, NFF-myofibroblast differentiation and soluble collagen production; and was an effective scavenger of the model oxidant, 2,2-diphenyl-1-picrylhydrazyl (DPPH·), with an EC50 value of 44.7 ± 3.1 µM. These findings reveal significant anti-fibrotic potential for cerumen-derived tomentosenol A (1)

Ecological and Cultural Understanding as a Basis for Management of a Globally Significant Island Landscape

Islands provide the opportunity to explore management regimes and research issues related to the isolation, uniqueness, and integrity of ecological systems. K’gari (Fraser Island) is an Australian World Heritage property listed based on its outstanding natural value, specifically, the unique wilderness characteristics and the diversity of ecosystem types. Our goal was to draw on an understanding of the natural and cultural environment of K’gari as a foundation on which to build a management model that includes First Nations Peoples in future management and research. Our research involved an analysis of papers in the peer-reviewed scientific literature, original reports, letters, and other manuscripts now housed in the K’gari Fraser Island Research Archive. The objectives of the research were: (1) to review key historical events that form the cultural, social, and environmental narrative; (2) review the major natural features of the island and threats; (3) identify the gaps in research; (4) analyse the management and conservation challenges associated with tourism, biosecurity threats, vegetation management practices, and climate change and discuss whether the requirements for sustaining island ecological integrity can be met in the future; and (5) identify commonalities and general management principles that may apply globally to other island systems and other World Heritage sites listed on the basis of their unique natural and cultural features. We found that the characteristics that contribute to island uniqueness are also constraints for research funding and publication; however, they are important themes that warrant more investment. Our review suggests that K’gari is a contested space between tourist visitation and associated environmental impacts, with an island that has rich First Nations history, extraordinary ecological diversity, and breathtaking aesthetic beauty. This juxtaposition is reflected in disparate views of custodianship and use, and the management strategies are needed to achieve multiple objectives in an environmentally sustainable way whilst creating cultural equity in modern times. We offer a foundation on which to build a co-management model that includes First Nations Peoples in governance, management, research, and monitoring

Transcriptional Repression of the Plasminogen Activator Inhibitor Type 2 Gene

Plasminogen activator inhibitor type 2 (PAI-2) is a serine protease inhibitor traditionally regarded as a regulator of fibrinolysis and extracellular matrix degradation. More recently, PAI-2 has been implicated in diverse processes such as keratinocyte differentiation, cell death and viral pathogenesis. Although PAI-2s limited pattern of expression in vivo generates significant interest in this molecule, little is known about the underlying mechanisms controlling its cell specific regulation. In this thesis, the function that the previously identified PAI-2 gene silencer (Antalis et al., 1996) plays in the regulation of PAI-2 gene expression was investigated. The PAI-2 upstream silencer element 1 (PAUSE-1) is located approximately 1800bp upstream of the PAI-2 transcription initiation site. By employing electrophoretic mobility shift assays and transient transfection assays with mutant PAUSE-1 sequences, the sequence that defines PAUSE-1 was identified as TCT N3 AGA N3 T4. This element was shown to bind a number of protein complexes of similar electrophoretic mobility from various cultured cell lines. Transient transfection assays with the cervical adenocarcinoma, HeLa S3 and the macrophage-like, U937 cell lines, showed that PAUSE-1 repressed transcription by approximately 2.5 fold when cloned into the SV40 promoter or the minimal PAI-2 promoter. Ultraviolet (UV)-crosslinking analyses determined that the PAUSE-1 binding protein (BP) was approximately 67kDa. Examination of several similar DNA promoter sequences, such as the human IFNb and insulin promoters, suggested that PAUSE-1 might be an example of a universal silencer with the consensus sequence TCT Nx AGA, where x=4. The PAUSE-1 sequence shows significant homology to the binding sequence of the transcriptional regulators Ski, Smad3 and Smad4. EMSAs incorporating anti-Ski, -Smad3 and -Smad4 antibodies suggested that each are members of the PAUSE-1 BP complex in HeLa S3 cells. The PAUSE-1 BP complex has been purified by employing DNA affinity chromatography using streptavidin labelled magnetic beads. Approximately nine PAUSE-1 associated proteins from HeLa S3 extracts were visualised. Amino-terminal protein sequencing identified the first eight amino acids of the PAUSE-1 BP as EIQQRAAQ. The PAUSE-1 BP fails to show significant sequence similarity to any known protein and therefore potentially represents a novel DNA binding protein

Eco-toxicological effects of the avermectin family with a focus on abamectin and ivermectin

Hosseini Bai, S ORCiD: 0000-0001-8646-6423Avermectin family members are categorised as highly effective but toxic natural products that are used as pharmaceuticals in both humans and animals and for crop protection. Abamectin and ivermectin are the two most commonly used compounds from this family with abamectin the only compound to be used for both crop protection and pharmaceutical purposes. Avermectins are produced by the soil dwelling actinomycetes Streptomyces avermitilis and despite having complex chemical structures, they are manufactured via synthesis in large scales for commercial use.Although the extent of the eco-toxicological effects of avermectins is not well documented, reports of eco-toxicity exist. Avermectins have short half-lives and their residues can be eliminated through different food processing methods. However, avermectins can persist in water, sediment, soil and food products and therefore management practices that reduce the potential risks associated with eco-toxicity of these highly toxic compounds need to be further developed. This manuscript provides a critical review of the eco-toxicological risks and the potential for food contamination associated with avermectin use. © 2016 Elsevier Ltd

Characterisation of PAUSE-1, a powerful silencer in the human plasminogen activator inhibitor type 2 gene promoter

Plasminogen activator inhibitor type 2 (PAI-2) is a serine protease inhibitor traditionally regarded as a regulator of fibrinolysis and extracellular matrix degradation. More recently, PAI-2 has been implicated in diverse processes such as keratinocyte differentiation, cell death and viral pathogenesis. The PAI-2 promoter tightly regulates PAI-2 gene expression in a cell-specific manner and this control is mediated, in part, by the upstream silencer element, PAUSE-1. Here we have defined PAUSE-1 and investigated its activity as a silencer. A series of mutations were generated within the PAUSE-1 element and analysed for transcription factor binding and transcriptional silencing activity. These studies have defined the minimal functional PAUSE-1 element as TCTN(x)AGAN(3)T(4), where x = 0, 2 or 4. Examination of related elements present in other promoters, such as the human IFNβ promoter, suggests that PAUSE-1 is a member of a family of universal silencers with the consensus sequence TCTN(x)AGA. UV crosslinking analyses determined that the PAUSE-1 binding protein was ∼67 kDa. Insertion of PAUSE-1 into the heterologous (SV40) or the minimal PAI-2 promoters silenced transcription by 2.5-fold. These data show that PAUSE-1 acts as a powerful silencer of PAI-2 gene transcription and is likely to be important in the silencing of other genes as well

Glyphosate: Environmental contamination, toxicity and potential risks to human health via food contamination

Hosseini Bai, S ORCiD: 0000-0001-8646-6423Glyphosate has been the most widely used herbicide during the past three decades. The US Environmental Protection Agency (EPA) classifies glyphosate as ‘practically non-toxic and not an irritant’ under the acute toxicity classification system. This classification is based primarily on toxicity data and due to its unique mode of action via a biochemical pathway that only exists in a small number of organisms that utilise the shikimic acid pathway to produce amino acids, most of which are green plants. This classification is supported by the majority of scientific literature on the toxic effects of glyphosate. However, in 2005, the Food and Agriculture Organisation (FAO) reported that glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA), are of potential toxicological concern, mainly as a result of accumulation of residues in the food chain. The FAO further states that the dietary risk of glyphosate and AMPA is unlikely if the maximum daily intake of 1 mg kg−1body weight (bw) is not exceeded. Research has now established that glyphosate can persist in the environment, and therefore, assessments of the health risks associated with glyphosate are more complicated than suggested by acute toxicity data that relate primarily to accidental high-rate exposure. We have used recent literature to assess the possible risks associated with the presence of glyphosate residues in food and the environment. © 2016, Springer-Verlag Berlin Heidelberg