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O’Byrne Alice M. Lambourn Dyanna M. Rejmanek Daniel Haman Katherine O’Byrne Michael VanWormer Elizabeth Shapiro Karen 《EcoHealth》2021,18(1):84-94
EcoHealth - Increasing reports of marine mammal deaths have been attributed to the parasite Sarcocystis neurona. Infected opossums, the only known definitive hosts, shed S. neurona sporocysts in... 相似文献
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Genetic containment of forest plantations 总被引:2,自引:0,他引:2
Amy M. Brunner Jingyi Li Stephen P. DiFazio Olga Shevchenko Brooke E. Montgomery Rozi Mohamed Hao Wei Cathleen Ma Ani Anna Elias Katherine VanWormer Steven H. Strauss 《Tree Genetics & Genomes》2007,3(2):75-100
Dispersal of pollen, seeds, or vegetative propagules from intensively bred, exotic, or recombinant DNA modified forest plantations
may cause detrimental or beneficial ecological impacts on wild or managed ecosystems. Insertion of genes designed to prevent
or substantially reduce dispersal could reduce the risk and extent of undesired impacts. Containment measures may also be
required by law or marketplace constraints, regardless of risks or benefits. We discuss: (1) the context for when genetic
containment or mitigation systems may be needed; (2) technology approaches and mechanisms; (3) the state of knowledge on genes/genomics
of sexual reproduction in forest trees; (4) stability of transgene expression during vegetative growth; (5) simulation studies
to define the level of containment needed; and (6) needed research to deliver effective containment technologies. We illustrate
progress with several examples from our research on recombinant DNA modified poplars. Our simulations show that even partial
sterility can provide very substantial reductions in gene flow into wild trees. We conclude that it is impossible to define
the most effective containment approaches, nor their reliability, based on current genomic knowledge and technological tools.
Additional genomic and technological studies of a wide variety of options are needed. Studies in field environments are essential
to provide data relevant to ecological analysis and regulatory decisions and need to be carried out in phylogenetically diverse
representatives of the economically most important taxa of forest trees.
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Steven H. StraussEmail: |
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Michelle L. Verant Noemi d’Ozouville Patricia G. Parker Karen Shapiro Elizabeth VanWormer Sharon L. Deem 《EcoHealth》2014,11(2):207-214
Toxoplasmosis is a health concern for wildlife and humans, particularly in island ecosystems. In the Galápagos Islands, exposure to Toxoplasma gondii has been found in marine avifauna on islands with and without domestic cats. To evaluate potential waterborne transmission of T. gondii, we attempted to use filtration and epifluorescent microscopy to detect autofluorescent T. gondii oocysts in fresh and estuarine surface water samples. T. gondii oocyst-like structures were microscopically visualized but were not confirmed by polymerase chain reaction and sequence analyses. Further research is needed to refine environmental pathogen screening techniques and to evaluate disease risk of waterborne zoonoses such as T. gondii for wildlife and humans, particularly in the Galápagos and other naive island ecosystems. 相似文献
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Elizabeth VanWormer Patricia A. Conrad Melissa A. Miller Ann C. Melli Tim E. Carpenter Jonna A. K. Mazet 《EcoHealth》2013,10(3):277-289
Environmental transmission of Toxoplasma gondii, a global zoonotic parasite, adversely impacts human and animal health. Toxoplasma is a significant cause of mortality in threatened Southern sea otters, which serve as sentinels for disease threats to people and animals in coastal environments. As wild and domestic felids are the only recognized hosts capable of shedding Toxoplasma oocysts into the environment, otter infection suggests land-to-sea pathogen transmission. To assess relative contributions to terrestrial parasite loading, we evaluated infection and shedding among managed and unmanaged feral domestic cats, mountain lions, and bobcats in coastal California, USA. Infection prevalence differed among sympatric felids, with a significantly lower prevalence for managed feral cats (17%) than mountain lions, bobcats, or unmanaged feral cats subsisting on wild prey (73–81%). A geographic hotspot of infection in felids was identified near Monterey Bay, bordering a high-risk site for otter infection. Increased odds of oocyst shedding were detected in bobcats and unmanaged feral cats. Due to their large populations, pet and feral domestic cats likely contribute more oocysts to lands bordering the sea otter range than native wild felids. Continued coastal development may influence felid numbers and distribution, increase terrestrial pathogens in freshwater runoff, and alter disease dynamics at the human–animal–environment interface. 相似文献
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Elizabeth VanWormer Melissa A. Miller Patricia A. Conrad Michael E. Grigg Daniel Rejmanek Tim E. Carpenter Jonna A. K. Mazet 《PLoS neglected tropical diseases》2014,8(5)
Background
Environmental transmission of the zoonotic parasite Toxoplasma gondii, which is shed only by felids, poses risks to human and animal health in temperate and tropical ecosystems. Atypical T. gondii genotypes have been linked to severe disease in people and the threatened population of California sea otters. To investigate land-to-sea parasite transmission, we screened 373 carnivores (feral domestic cats, mountain lions, bobcats, foxes, and coyotes) for T. gondii infection and examined the distribution of genotypes in 85 infected animals sampled near the sea otter range.Methodology/Principal Findings
Nested PCR-RFLP analyses and direct DNA sequencing at six independent polymorphic genetic loci (B1, SAG1, SAG3, GRA6, L358, and Apico) were used to characterize T. gondii strains in infected animals. Strains consistent with Type X, a novel genotype previously identified in over 70% of infected sea otters and four terrestrial wild carnivores along the California coast, were detected in all sampled species, including domestic cats. However, odds of Type X infection were 14 times higher (95% CI: 1.3–148.6) for wild felids than feral domestic cats. Type X infection was also linked to undeveloped lands (OR = 22, 95% CI: 2.3–250.7). A spatial cluster of terrestrial Type II infection (P = 0.04) was identified in developed lands bordering an area of increased risk for sea otter Type II infection. Two spatial clusters of animals infected with strains consistent with Type X (P≤0.01) were detected in less developed landscapes.Conclusions
Differences in T. gondii genotype prevalence among domestic and wild felids, as well as the spatial distribution of genotypes, suggest co-existing domestic and wild T. gondii transmission cycles that likely overlap at the interface of developed and undeveloped lands. Anthropogenic development driving contact between these cycles may increase atypical T. gondii genotypes in domestic cats and facilitate transmission of potentially more pathogenic genotypes to humans, domestic animals, and wildlife. 相似文献
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