136 research outputs found

    ο»ΏScalability of genetic biocontrols for eradicating invasive alien mammals

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    CRISPR-based gene drives offer novel solutions for controlling invasive alien species, which could ultimately extend eradication efforts to continental scales. Gene drives for suppressing invasive alien vertebrates are now under development. Using a landscape-scale individual-based model, we present the first estimates of times to eradication for long-lived alien mammals. We show that demography and life-history traits interact to determine the scalability of gene drives for vertebrate pest eradication. Notably, optimism around eradicating smaller-bodied pests (rodents and rabbits) with gene-drive technologies does not easily translate into eradication of larger-bodied alien species (cats and foxes).Aysegul Birand, Phillip Cassey, Joshua V. Ross, Paul Q. Thomas, Thomas A. A. Prows

    GLI1 confers profound phenotypic changes upon LNCaP prostate cancer cells that include the acquisition of a hormone independent state

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    The GLI (GLI1/GLI2) transcription factors have been implicated in the development and progression of prostate cancer although our understanding of how they actually contribute to the biology of these common tumours is limited. We observed that GLI reporter activity was higher in normal (PNT-2) and tumourigenic (DU145 and PC-3) androgen-independent cells compared to androgen-dependent LNCaP prostate cancer cells and, accordingly, GLI mRNA levels were also elevated. Ectopic expression of GLI1 or the constitutively active NGLI2 mutant induced a distinct cobblestone-like morphology in LNCaP cells that, regarding the former, correlated with increased GLI2 as well as expression of the basal/stem-like markers CD44, beta1-integrin, Np63 and BMI1, and decreased expression of the luminal marker AR (androgen receptor). LNCaP-GLI1 cells were viable in the presence of the AR inhibitor bicalutamide and gene expression profiling revealed that the transcriptome of LNCaP-GLI1 cells was significantly closer to DU145 and PC-3 cells than to control LNCaP-pBP (empty vector) cells, as well as identifying LCN2/NGAL as a highly induced transcript which is associated with hormone independence in breast and prostate cancer. Functionally, LNCaP-GLI1 cells displayed greater clonal growth and were more invasive than control cells but they did not form colonies in soft agar or prostaspheres in suspension suggesting that they do not possess inherent stem cell properties. Moreover, targeted suppression of GLI1 or GLI2 with siRNA did not reverse the transformed phenotype of LNCaP-GLI1 cells nor did double GLI1/GLI2 knockdowns activate AR expression in DU145 or PC-3 cells. As such, early targeting of the GLI oncoproteins may hinder progression to a hormone independent state but a more detailed understanding of the mechanisms that maintain this phenotype is required to determine if their inhibition will enhance the efficacy of anti-hormonal therapy through the induction of a luminal phenotype and increased dependency upon AR function

    Nuclear and nucleon transitions of the H di-baryon

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    We consider 3 types of processes pertinent to the phenomenology of an H di-baryon: conversion of two Ξ›\Lambda's in a doubly-strange hypernucleus to an H, decay of the H to two baryons, and -- if the H is light enough -- conversion of two nucleons in a nucleus to an H. We compute the spatial wavefunction overlap using the Isgur-Karl and Bethe-Goldstone wavefunctions, and treat the weak interactions phenomenologically. The observation of Ξ›\Lambda decays from doubly-strange hypernuclei puts a constraint on the H wavefunction which is plausibly satisfied. In this case the H is very long-lived as we calculate. An absolutely stable H is not excluded at present. SuperK can provide valuable limits

    Dihyperon in Chiral Colour Dielectric Model

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    The mass of dihyperon with spin, parity JΟ€=0+J^{\pi}=0^{+} and isospin I=0I = 0 is calculated in the framework of Chiral colour dielectric model. The wave function of the dihyperon is expressed as a product of two colour-singlet baryon clusters. Thus the quark wave functions within the cluster are antisymmetric. Appropriate operators are then used to antisymmetrize inter-cluster quark wave functions. The radial part of the quark wavefunctions are obtained by solving the the quark and dielectric field equations of motion obtained in the Colour dielectric model. The mass of the dihyperon is computed by including the colour magnetic energy as well as the energy due to meson interaction. The recoil correction to the dihyperon mass is incorporated by Peierls-Yoccoz technique. We find that the mass of the dihyperon is smaller than the Ξ›βˆ’Ξ›\Lambda-\Lambda threshold by over 100 MeV. The implications of our results on the present day relativistic heavy ion experiments is discussed.Comment: LaTeX, 13 page

    Leveraging a natural murine meiotic drive to suppress invasive populations

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    Invasive rodents are a major cause of environmental damage and biodiversity loss, particularly on islands. Unlike insects, genetic biocontrol strategies including populationsuppressing gene drives with biased inheritance have not been developed in mice. Here, we demonstrate a gene drive strategy (tCRISPR) that leverages super-Mendelian transmission of the t haplotype to spread inactivating mutations in a haplosufficient female fertility gene (Prl). Using spatially explicit individual-based in silico modeling, we show that tCRISPR can eradicate island populations under a range of realistic field-based parameter values. We also engineer transgenic tCRISPR mice that, crucially, exhibit biased transmission of the modified t haplotype and Prl mutations at levels our modeling predicts would be sufficient for eradication. This is an example of a feasible gene drive system for invasive alien rodent population control.Luke Gierusa, Aysegul Birandc, Mark D. Buntinga, Gelshan I. Godahewa, Sandra G. Piltz Kevin P. Oh, Antoinette J. Piaggio, David W. Threadgill, John Godwin, Owain Edwards, Phillip Cassey, Joshua V. Ross, Thomas A. A. Prowse and Paul Q. Thoma

    Environment and shipping drive environmental DNA beta-diversity among commercial ports

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    The spread of nonindigenous species by shipping is a large and growing global problem that harms coastal ecosystems and economies and may blur coastal biogeographical patterns. This study coupled eukaryotic environmental DNA (eDNA) metabarcoding with dissimilarity regression to test the hypothesis that ship-borne species spread homogenizes port communities. We first collected and metabarcoded water samples from ports in Europe, Asia, Australia and the Americas. We then calculated community dissimilarities between port pairs and tested for effects of environmental dissimilarity, biogeographical region and four alternative measures of ship-borne species transport risk. We predicted that higher shipping between ports would decrease community dissimilarity, that the effect of shipping would be small compared to that of environment dissimilarity and shared biogeography, and that more complex shipping risk metrics (which account for ballast water and stepping-stone spread) would perform better. Consistent with our hypotheses, community dissimilarities increased significantly with environmental dissimilarity and, to a lesser extent, decreased with ship-borne species transport risks, particularly if the ports had similar environments and stepping-stone risks were considered. Unexpectedly, we found no clear effect of shared biogeography, and that risk metrics incorporating estimates of ballast discharge did not offer more explanatory power than simpler traffic-based risks. Overall, we found that shipping homogenizes eukaryotic communities between ports in predictable ways, which could inform improvements in invasive species policy and management. We demonstrated the usefulness of eDNA metabarcoding and dissimilarity regression for disentangling the drivers of large-scale biodiversity patterns. We conclude by outlining logistical considerations and recommendations for future studies using this approach.Fil: AndrΓ©s, Jose. Cornell University. Department Of Ecology And Evolutionary Biology;Fil: Czechowski, Paul. Cornell University. Department Of Ecology And Evolutionary Biology; . University of Otago; Nueva Zelanda. Helmholtz Institute for Metabolic, Obesity and Vascular Research; AlemaniaFil: Grey, Erin. University of Maine; Estados Unidos. Governors State University; Estados UnidosFil: Saebi, Mandana. University of Notre Dame; Estados UnidosFil: Andres, Kara. Cornell University. Department Of Ecology And Evolutionary Biology;Fil: Brown, Christopher. California State University Maritime Academy; Estados UnidosFil: Chawla, Nitesh. University of Notre Dame; Estados UnidosFil: Corbett, James J.. University of Delaware; Estados UnidosFil: Brys, Rein. Research Institute for Nature and Forest; BΓ©lgicaFil: Cassey, Phillip. University of Adelaide; AustraliaFil: Correa, Nancy. Ministerio de Defensa. Armada Argentina. Instituto Universitario Naval de la Ara. Escuela de Ciencias del Mar; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de HidrografΓ­a Naval; ArgentinaFil: Deveney, Marty R.. South Australian Research And Development Institute; AustraliaFil: Egan, Scott P.. Rice University; Estados UnidosFil: Fisher, Joshua P.. United States Fish and Wildlife Service; Estados UnidosFil: vanden Hooff, Rian. Oregon Department of Environmental Quality; Estados UnidosFil: Knapp, Charles R.. Daniel P. Haerther Center for Conservation and Research; Estados UnidosFil: Leong, Sandric Chee Yew. National University of Singapore; SingapurFil: Neilson, Brian J.. State of Hawaii Division of Aquatic Resources; Estados UnidosFil: Paolucci, Esteban Marcelo. Consejo Nacional de Investigaciones CientΓ­ficas y TΓ©cnicas. Oficina de CoordinaciΓ³n Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Pfrender, Michael E.. University of Notre Dame; Estados UnidosFil: Pochardt, Meredith R.. M. Rose Consulting; Estados UnidosFil: Prowse, Thomas A. A.. University of Adelaide; AustraliaFil: Rumrill, Steven S.. Oregon Department of Fish and Wildlife; Estados UnidosFil: Scianni, Chris. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto para el Estudio de la Biodiversidad de Invertebrados; Argentina. Marine Invasive Species Program; Estados UnidosFil: Sylvester, Francisco. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto para el Estudio de la Biodiversidad de Invertebrados; Argentina. Consejo Nacional de Investigaciones CientΓ­ficas y TΓ©cnicas. Centro CientΓ­fico TecnolΓ³gico Conicet - Salta; ArgentinaFil: Tamburri, Mario N.. University of Maryland; Estados UnidosFil: Therriault, Thomas W.. Pacific Biological Station; CanadΓ‘Fil: Yeo, Darren C. J.. National University of Singapore; SingapurFil: Lodge, David M.. Cornell University. Department Of Ecology And Evolutionary Biology

    The Observed Correlations for the Strange Multibaryon States in Systems with Ξ›\Lambda-Hyperon from pa Collision at Momentum of 10 Gev/cc

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    he observed well-known resonances Ξ£0\Sigma^0 Ξ£βˆ—+\Sigma^{*+}(1385) and Kβˆ—Β±K^{*\pm}(892) from PDG are good tests of this method. Exotic strange multibaryon states have been observed in the effective mass spectra of: Λπ±\Lambda \pi^{\pm},Λγ\Lambda \gamma, Ξ›p\Lambda p, Ξ›pp\Lambda p p subsystems. The mean value of mass for Ξ£βˆ—βˆ’(1385)\Sigma^{*-}(1385) resonance is shifted till mass of 1370 MeV/c2c^2 and width is two times larger than the same value from PDG. Such kind of behavior for width and invariant mass of Ξ£βˆ—βˆ’(1385)\Sigma^{*-}(1385) resonance is interpreted as extensive contribution from stopped Ξžβˆ’β†’Ξ›Ο€βˆ’\Xi^-\to\Lambda\pi^- and medium effect with invariant mass. The mean value of mass for Ξ£βˆ—+(1385)\Sigma^{*+}(1385) from secondary interactions is also shifted till mass of 1370 MeV/c2c^2. The width of Ξ£0\Sigma^0 is β‰ˆ\approx 2 times larger than the experimental error. There are enhancement production for all observed hyperons.Comment: 4 pages, 6 figures, XXIst Rencontres de Blois "Windows on the Universe " Blois, France June 21st - June 26th, 200

    Genetic variation exists for telomeric array organization within and among the genomes of normal, immortalized, and transformed chicken systems

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    This study investigated telomeric array organization of diverse chicken genotypes utilizing in vivo and in vitro cells having phenotypes with different proliferation potencies. Our experimental objective was to characterize the extent and nature of array variation present to explore the hypothesis that mega-telomeres are a universal and fixed feature of chicken genotypes. Four different genotypes were studied including normal (UCD 001, USDA-ADOL Line 0), immortalized (DF-1), and transformed (DT40) cells. Both cytogenetic and molecular approaches were utilized to develop an integrated view of telomeric array organization. It was determined that significant variation exists within and among chicken genotypes for chromosome-specific telomeric array organization and total genomic-telomeric sequence content. Although there was variation for mega-telomere number and distribution, two mega-telomere loci were in common among chicken genetic lines (GGA 9 and GGA W). The DF-1 cell line was discovered to maintain a complex derivative karyotype involving chromosome fusions in the homozygous and heterozygous condition. Also, the DF-1 cell line was found to contain the greatest amount of telomeric sequence per genome (17%) as compared to UCD 001 (5%) and DT40 (1.2%). The chicken is an excellent model for studying unique and universal features of vertebrate telomere biology, and characterization of the telomere length variation among genotypes will be useful in the exploration of mechanisms controlling telomere length maintenance in different cell types having unique phenotypes

    GLI1 Confers Profound Phenotypic Changes upon LNCaP Prostate Cancer Cells That Include the Acquisition of a Hormone Independent State

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    The GLI (GLI1/GLI2) transcription factors have been implicated in the development and progression of prostate cancer although our understanding of how they actually contribute to the biology of these common tumours is limited. We observed that GLI reporter activity was higher in normal (PNT-2) and tumourigenic (DU145 and PC-3) androgen-independent cells compared to androgen-dependent LNCaP prostate cancer cells and, accordingly, GLI mRNA levels were also elevated. Ectopic expression of GLI1 or the constitutively active Ξ”NGLI2 mutant induced a distinct cobblestone-like morphology in LNCaP cells that, regarding the former, correlated with increased GLI2 as well as expression of the basal/stem-like markers CD44, Ξ²1-integrin, Ξ”Np63 and BMI1, and decreased expression of the luminal marker AR (androgen receptor). LNCaP-GLI1 cells were viable in the presence of the AR inhibitor bicalutamide and gene expression profiling revealed that the transcriptome of LNCaP-GLI1 cells was significantly closer to DU145 and PC-3 cells than to control LNCaP-pBP (empty vector) cells, as well as identifying LCN2/NGAL as a highly induced transcript which is associated with hormone independence in breast and prostate cancer. Functionally, LNCaP-GLI1 cells displayed greater clonal growth and were more invasive than control cells but they did not form colonies in soft agar or prostaspheres in suspension suggesting that they do not possess inherent stem cell properties. Moreover, targeted suppression of GLI1 or GLI2 with siRNA did not reverse the transformed phenotype of LNCaP-GLI1 cells nor did double GLI1/GLI2 knockdowns activate AR expression in DU145 or PC-3 cells. As such, early targeting of the GLI oncoproteins may hinder progression to a hormone independent state but a more detailed understanding of the mechanisms that maintain this phenotype is required to determine if their inhibition will enhance the efficacy of anti-hormonal therapy through the induction of a luminal phenotype and increased dependency upon AR function
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