202 research outputs found

    Genomics clarifies taxonomic boundaries in a difficult species complex.

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    Efforts to taxonomically delineate species are often confounded with conflicting information and subjective interpretation. Advances in genomic methods have resulted in a new approach to taxonomic identification that stands to greatly reduce much of this conflict. This approach is ideal for species complexes, where divergence times are recent (evolutionarily) and lineages less well defined. The California Roach/Hitch fish species complex is an excellent example, experiencing a convoluted geologic history, diverse habitats, conflicting species designations and potential admixture between species. Here we use this fish complex to illustrate how genomics can be used to better clarify and assign taxonomic categories. We performed restriction-site associated DNA (RAD) sequencing on 255 Roach and Hitch samples collected throughout California to discover and genotype thousands of single nucleotide polymorphism (SNPs). Data were then used in hierarchical principal component, admixture, and FST analyses to provide results that consistently resolved a number of ambiguities and provided novel insights across a range of taxonomic levels. At the highest level, our results show that the CA Roach/Hitch complex should be considered five species split into two genera (4 + 1) as opposed to two species from distinct genera (1 +1). Subsequent levels revealed multiple subspecies and distinct population segments within identified species. At the lowest level, our results indicate Roach from a large coastal river are not native but instead introduced from a nearby river. Overall, this study provides a clear demonstration of the power of genomic methods for informing taxonomy and serves as a model for future studies wishing to decipher difficult species questions. By allowing for systematic identification across multiple scales, taxonomic structure can then be tied to historical and contemporary ecological, geographic or anthropogenic factors

    Investigation of Bombesin peptide as a targeting ligand for the gastrin releasing peptide (GRP) receptor

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    Gastrin releasing peptide (GRP) receptor (GRPR), a bombesin family receptor, is overexpressed in many cancers including breast, prostate, pancreatic and lung. The targeting of therapeutics to GRPR can be achieved using the full-length (14 amino acid) GRP analogue Bombesin (BBN) or the truncated BBN(6-14) sequence, both of which bind GRPR with high affinity and specificity. In this study, we have investigated the level of GRPR expression in various cancerous (Caco-2, HeLa, LNCap, MDA-MB-231, and PC-3) and non-cancerous (WPMY-1) cell lines using a western blotting approach. Such information is currently lacking in the literature, and is therefore of importance for the in vitro assessment of GRPR targeted therapeutics. Of the cell lines assessed, the PC-3 (prostate cancer) and Caco-2 (colon cancer) cell lines demonstrated the highest and lowest levels of GRPR expression respectively. Using this information, we further investigated the cellular uptake of carboxyfluorescein-labelled BBN and BBN(6-14) peptides by flow cytometry and confocal microscopy using cell lines that express GRPR (Caco-2, HeLa, PC-3). The uptake of each of these peptides was similar, suggesting that the shorter BBN(6-14) peptide is sufficient for GRPR targeting. Further, the uptake of these peptides could be inhibited by competition with unlabelled BBN peptides, suggesting their cellular uptake is GRPR-mediated, while the level of BBN uptake (as measured by flow cytometry) was found to be directly proportional to the level of GRPR expression. Overall, the information obtained from these studies provides useful information for the in vitro assessment of GRPR targeted therapeutics. (C) 2016 Elsevier Ltd. All rights reserved

    An efficient, chemically-defined semisynthetic lipid-adjuvanted nanoparticulate vaccine development system

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    A novel vaccine development platform that enables the site-specific conjugation of synthetic lipid adjuvants to recombinant proteins was produced. This technology facilitates the simple and efficient production of homogeneous, chemically-defined, semisynthetic lipoprotein vaccines. Using a polytope 'string-of-beads' approach, a synthetic gene incorporating seven Streptococcus pyogenes M protein strain-specific antigens, and a conserved M protein antigen (J14) was produced, expressed, and attached to a lipoamino acid based adjuvant (lipid core peptide; LCP). Nanoparticles (40 nm diameter) of an optimal size for stimulating antibody-mediated immunity were formed upon the addition of these lipoproteins to aqueous buffer (PBS). Systemic antigen-specific IgG antibodies were raised against all eight antigens in C57BL/6 J mice, without the need to formulate with additional adjuvant. These antibodies bound cell surface M proteins of S. pyogenes strains represented within the polytope sequence, with higher antibody levels observed where a dendritic cell targeting peptide (DCpep) was incorporated within the LCP adjuvant. Crown Copyright (C) 2013 Published by Elsevier Inc. All rights reserved

    Tectonic collision and uplift of Wallacea triggered the global songbird radiation

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    Songbirds (oscine passerines) are the most species-rich and cosmopolitan bird group, comprising almost half of global avian diversity. Songbirds originated in Australia, but the evolutionary trajectory from a single species in an isolated continent to worldwide proliferation is poorly understood. Here, we combine the first comprehensive genome-scale DNA sequence data set for songbirds, fossil-based time calibrations, and geologically informed biogeographic reconstructions to provide a well-supported evolutionary hypothesis for the group. We show that songbird diversification began in the Oligocene, but accelerated in the early Miocene, at approximately half the age of most previous estimates. This burst of diversification occurred coincident with extensive island formation in Wallacea, which provided the first dispersal corridor out of Australia, and resulted in independent waves of songbird expansion through Asia to the rest of the globe. Our results reconcile songbird evolution with Earth history and link a major radiation of terrestrial biodiversity to early diversification within an isolated Australian continent

    Climate vulnerability assessment for Pacific salmon and steelhead in the California Current Large Marine Ecosystem.

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    Major ecological realignments are already occurring in response to climate change. To be successful, conservation strategies now need to account for geographical patterns in traits sensitive to climate change, as well as climate threats to species-level diversity. As part of an effort to provide such information, we conducted a climate vulnerability assessment that included all anadromous Pacific salmon and steelhead (Oncorhynchus spp.) population units listed under the U.S. Endangered Species Act. Using an expert-based scoring system, we ranked 20 attributes for the 28 listed units and 5 additional units. Attributes captured biological sensitivity, or the strength of linkages between each listing unit and the present climate; climate exposure, or the magnitude of projected change in local environmental conditions; and adaptive capacity, or the ability to modify phenotypes to cope with new climatic conditions. Each listing unit was then assigned one of four vulnerability categories. Units ranked most vulnerable overall were Chinook (O. tshawytscha) in the California Central Valley, coho (O. kisutch) in California and southern Oregon, sockeye (O. nerka) in the Snake River Basin, and spring-run Chinook in the interior Columbia and Willamette River Basins. We identified units with similar vulnerability profiles using a hierarchical cluster analysis. Life history characteristics, especially freshwater and estuary residence times, interplayed with gradations in exposure from south to north and from coastal to interior regions to generate landscape-level patterns within each species. Nearly all listing units faced high exposures to projected increases in stream temperature, sea surface temperature, and ocean acidification, but other aspects of exposure peaked in particular regions. Anthropogenic factors, especially migration barriers, habitat degradation, and hatchery influence, have reduced the adaptive capacity of most steelhead and salmon populations. Enhancing adaptive capacity is essential to mitigate for the increasing threat of climate change. Collectively, these results provide a framework to support recovery planning that considers climate impacts on the majority of West Coast anadromous salmonids

    Biological Invasions: Recommendations for U.S. Policy and Management

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    The Ecological Society of America has evaluated current U.S. national policies and practices on biological invasions in light of current scientific knowledge. Invasions by harmful nonnative species are increasing in number and area affected; the damages to ecosystems, economic activity, and human welfare are accumulating. Without improved strategies based on recent scientific advances and increased investments to counter invasions, harm from invasive species is likely to accelerate. Federal leadership, with the cooperation of state and local governments, is required to increase the effectiveness of prevention of invasions, detect and respond quickly to new potentially harmful invasions, control and slow the spread of existing invasions, and provide a national center to ensure that these efforts are coordinated and cost effective. Specifically, the Ecological Society of America recommends that the federal government take the following six actions: (1) Use new information and practices to better manage commercial and other pathways to reduce the transport and release of potentially harmful species; (2) Adopt more quantitative procedures for risk analysis and apply them to every species proposed for importation into the country; (3) Use new cost-effective diagnostic technologies to increase active surveillance and sharing of information about invasive species so that responses to new invasions can be more rapid and effective; (4) Create new legal authority and provide emergency funding to support rapid responses to emerging invasions; (5) Provide funding and incentives for cost-effective programs to slow the spread of existing invasive species in order to protect still uninvaded ecosystems, social and industrial infrastructure, and human welfare; and (6) Establish a National Center for Invasive Species Management (under the existing National Invasive Species Council) to coordinate and lead improvements in federal, state, and international policies on invasive species. Recent scientific and technical advances provide a sound basis for more cost-effective national responses to invasive species. Greater investments in improved technology and management practices would be more than repaid by reduced damages from current and future invasive species. The Ecological Society of America is committed to assist all levels of government and provide scientific advice to improve all aspects of invasive-species management

    A Mysterious Island in the Digital Age: Technology and Musical Life in Ulleungdo, South Korea

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    This paper contributes to the growing body of ethnomusicological research about music-making on small islands, focusing on the remote South Korean island of Ulleungdo (literally, ‘Mysterious Island’). Historically, a number of factors have conspired to present serious obstacles to the Ulleungdo islanders' musical aspirations. However, since the early 1990s, enterprising amateurs have managed to generate and maintain a variety of musical activities in spite of these obstacles: church ensembles, karaoke, saxophone clubs, and more. Paralleling other island music studies, this paper seeks to show how the condition of being an Ulleungdo islander—entailing a complex of varied experiences, values, and relationships—has informed music-making over the years. However, here, the discussion remains firmly focused upon the islanders' use of technology since an acute reliance on technology has come to permeate Ulleungdo's musical life, with certain electronic devices commonly regarded as essential facilitators of musical expression. Drawing from the islanders' own testimonies, studies of Ulleungdo's cultural history, and works addressing technology's applications within and effects upon local communities, the authors explore how and why this condition of musical techno-reliance developed, how it is manifest in the present-day, and its broader implications for the island's music culture and identity
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