49 research outputs found

    Derivation of the molecular basis of endocrine disruption in aquatic invertebrates

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    Endocrine disrupting chemicals (EDCs) have attracted worldwide media attention due to their feminisation effects on aquatic organisms. Studies on the environmental effects of these compounds have become increasingly important due to fears of increased infertility and their influence on the dynamics of an ecological niche. The benthic invertebrate Gammarus pulex has been selected as a sentinel species for studying the effects of these pollutants on the amphipod endocrine system, and subsequently on reproduction. The aims of this project were to gain a greater understanding of the endocrine system of Gammarus pulex at the molecular level and to identify how pollutants may effect gene expression in intersex and normal Echinogammarus marinus. Two proteins found in this freshwater shrimp have been identified as possible molecular indices of endocrine disruption, the female specific yolk protein, vitellogenin, and the exoskeletal cuticle protein. Cuticle protein is the first molecular tool to deterrnine moult stage in G. pulex, which has previously relied on morphological microscopy. Rapid moult staging of cDNA, and subsequent analysis of gene expression at the different moult stages, are critical steps towards understanding normal and disrupted endocrine regulation and control. Increased vitellogenin levels in female G. pulex have confirmed its effectiveness as a sex-specific marker. The experimental processes and results presented have significantly enhanced not only the quantity of molecular knowledge of the freshwater amphipod G. pulex, but also offers great insight into the genetic profiles of different genders, developmental and moult cycle stages in G. pulex. It also provides important information on endocrine disruption and intersex gene expression profiles in a related species E. marinus. A major potential output from this study is the production of a suite of novel and established molecular markers to detect early stages of endocrine disruption in the ubiquitous benthic invertebrate, G. pulex and related amphipods

    Draft genome sequences of Phytophthora kernoviae and Phytophthora ramorum lineage EU2 from Scotland

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    Newly discovered Phytophthora species include invasive pathogens that threaten trees and shrubs. We present draft genome assemblies for three isolates of Phytophthora kernoviae and one isolate of the EU2 lineage of Phytophthora ramorum, collected from outbreak sites in Scotland

    Diversity of secoiridoid glycosides in leaves of UK and Danish ash provide new insight for ash dieback management

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    Secoiridoid glycosides are anti-feeding deterrents of the Oleaceae family recently highlighted as potential biomarkers in Danish ash trees to differentiate between those tolerant and susceptible to the fungal disease ash dieback. With the knowledge that emerald ash borer has recently entered Europe from Russia, and that extensive selection trials are ongoing in Europe for ash dieback tolerant European ash (Fraxinus excelsior), we undertook comprehensive screening of secoiridoid glycosides in leaf extracts of trees tolerant and susceptible to ash dieback sampled from sites in the UK and Denmark. Here we report an unexpected diversity of secoiridoid glycosides in UK trees and higher levels of secoiridoid glycosides in the UK sample group. While it is unlikely that secoiridoid glycosides generally can serve as reliable markers for ash dieback susceptibility, there are differences between tolerant and susceptible groups for specific secoiridoids. We predict that the high levels—and structural diversity—of secoiridoids present in the UK group may provide a robust reservoir of anti-feeding deterrents to mitigate future herbivore threats such as the Emerald ash borer

    Genome sequencing data for wild and cultivated bananas, plantains and abacá

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    We performed shotgun genome sequencing on a total of 19 different Musa genotypes including representatives of wild banana species Musa acuminata and M. balibisiana, allopolyploid bananas and plantains, Fe'i banana, pink banana (also known as hairy banana) and abacá (also known as hemp banana). We aligned sequence reads against a previously sequenced reference genome and assessed ploidy and, in the case of allopolyploids, the contributions of the A and B genomes; this provides important quality-assurance data about the taxonomic identities of the sequenced plant material. These data will be useful for phylogenetics, crop improvement, studies of the complex story of intergenomic recombination in AAB and ABB allotriploid bananas and plantains and can be integrated into resources such as the Banana Genome Hub

    Genome sequences of six Phytophthora species associated with forests in New Zealand

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    In New Zealand there has been a long association of Phytophthora diseases in forests, nurseries, remnant plantings and horticultural crops. However, new Phytophthora diseases of trees have recently emerged. Genome sequencing has been performed for 12 Phytophthora isolates, from six species: Phytophthora pluvialis, Phytophthora kernoviae, Phytophthora cinnamomi, Phytophthora agathidicida, Phytophthora multivora and Phytophthora taxon Totara. These sequences will enable comparative analyses to identify potential virulence strategies and ultimately facilitate better control strategies. This Whole Genome Shotgun data have been deposited in DDBJ/ENA/GenBank under the accession numbers LGTT00000000, LGTU00000000, JPWV00000000, JPWU00000000, LGSK00000000, LGSJ00000000, LGTR00000000, LGTS00000000, LGSM00000000, LGSL00000000, LGSO00000000, and LGSN0000000

    Functional analysis of RXLR effectors from the New Zealand kauri dieback pathogen Phytophthora agathidicida

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    New Zealand kauri is an ancient, iconic, gymnosperm tree species that is under threat from a lethal dieback disease caused by the oomycete Phytophthora agathidicida. To gain insight into this pathogen, we determined whether proteinaceous effectors of P. agathidicida interact with the immune system of a model angiosperm, Nicotiana, as previously shown for Phytophthora pathogens of angiosperms. From the P. agathidicida genome, we defined and analysed a set of RXLR effectors, a class of proteins that typically have important roles in suppressing or activating the plant immune system. RXLRs were screened for their ability to activate or suppress the Nicotiana plant immune system using Agrobacterium tumefaciens transient transformation assays. Nine P. agathidicida RXLRs triggered cell death or suppressed plant immunity in Nicotiana, of which three were expressed in kauri. For the most highly expressed, P. agathidicida (Pa) RXLR24, candidate cognate immune receptors associated with cell death were identified in Nicotiana benthamiana using RNA silencing-based approaches. Our results show that RXLRs of a pathogen of gymnosperms can interact with the immune system of an angiosperm species. This study provides an important foundation for studying the molecular basis of plant–pathogen interactions in gymnosperm forest trees, including kauri

    Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.

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    Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant
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