1,021 research outputs found
Ancient Host–Pathogen Associations Maintained by Specificity of Chemotaxis and Antibiosis
No full textNicole M Gerardo is with UT Austin and the Smithsonian Tropical Research Institute, Sarah R Jacobs is with UT Austin and Duke University, Cameron R Currie is with the Smithsonian Tropical Research Institute and University of Wisconsin at Madison, Ulrich G Mueller is with UT Austin and the Smithsonian Tropical Research Institute.Switching by parasites to novel hosts has profound effects on ecological and evolutionary disease dynamics. Switching requires that parasites are able to establish contact with novel hosts and to overcome host defenses. For most host–parasite associations, it is unclear as to what specific mechanisms prevent infection of novel hosts. Here, we show that parasitic fungal species in the genus Escovopsis, which attack and consume the fungi cultivated by fungus-growing ants, are attracted to their hosts via chemotaxis. This response is host-specific: Escovopsis spp. grow towards their natural host cultivars more rapidly than towards other closely related fungi. Moreover, the cultivated fungi secrete compounds that can suppress Escovopsis growth. These antibiotic defenses are likewise specific: in most interactions, cultivars can inhibit growth of Escovopsis spp. not known to infect them in nature but cannot inhibit isolates of their naturally infecting pathogens . Cases in which cultivars are susceptible to novel Escovopsis are limited to a narrow set of host–parasite strain combinations. Targeted chemotactic and antibiotic responses therefore explain why Escovopsis pathogens do not readily switch to novel hosts, consequently constraining long-term dynamics of host–parasite coevolution within this ancient association.This work was supported by NSF Doctoral Dissertation Improvement Grant DEB-0308757 to NMG; NSF IRCEB Grant DEB-0110073 to CRC and UGM, and fellowships to NMG from the University of Texas at Austin Graduate School and the U.T. Department of Integrative Biology.Biological Sciences, School o
The antimicrobial potential from insect microbiomes of Streptomyces
No full textChevrette, Marc G., Carlson, Caitlin M., Ortega, Humberto E., Thomas, Chris, Ananiev, Gene E., Barns, Kenneth J., Book, Adam J., Cagnazzo, Julian, Carlos, Camila, Flanigan, Will, Grubbs, Kirk J., Horn, Heidi A., Hoffmann, Michael, Klassen, Jonathan L., Knack, Jennifer J., Lewin, Gina R., McDonald, Bradon R., Mulle, Laura, Melo, Weilan G.P., Pinto-Tomás, Adrián A., Schmitz, Amber, Wendt-Pienkowski, Evelyn, Wildman, Scott, Zhao, Miao, Zhang, Fan, Bugni, Tim S., Andes, David R., Pupo, Monica T., Currie, Cameron R. (2019): The antimicrobial potential from insect microbiomes of Streptomyces. Nature Communications 10 (516): 1-11, DOI: 10.1038/s41467-019-08438-
Preliminary In Vitro Insights into the Use of Natural Fungal Pathogens of Leaf-cutting Ants as Biocontrol Agents
No full textLeaf-cutting ants are one of the main herbivores of the Neotropics, where they represent an important agricultural pest. These ants are particularly difficult to control because of the complex network of microbial symbionts. Leaf-cutting ants have traditionally been controlled through pesticide application, but there is a need for alternative, more environmentally friendly, control methods such as biological control. Potential promising biocontrol candidates include the microfungi Escovopsis spp. (anamorphic Hypocreales), which are specialized pathogens of the fungi the ants cultivate for food. These pathogens are suppressed through ant behaviors and ant-associated antibiotic-producing Actinobacteria. In order to be an effective biocontrol agent, Escovopsis has to overcome these defenses. Here, we evaluate, using microbial in vitro assays, whether defenses in the ant-cultivated fungus strain (Leucoagaricus sp.) and Actinobacteria from the ant pest Acromyrmex lundii have the potential to limit the use of Escovopsis in biocontrol. We also explore, for the first time, possible synergistic biocontrol between Escovopsis and the entomopathogenic fungus Lecanicillium lecanii. All strains of Escovopsis proved to overgrow A. lundii cultivar in less than 7 days, with the Escovopsis strain isolated from a different leaf-cutting ant species being the most efficient. Escovopsis challenged with a Streptomyces strain isolated from A. lundii did not exhibit significant growth inhibition. Both results are encouraging for the use of Escovopsis as a biocontrol agent. Although we found that L. lecanii can suppress the growth of the cultivar, it also had a negative impact on Escovopsis, making the success of simultaneous use of these two fungi for biocontrol of A. lundii questionable.Fil: Folgarait, Patricia Julia. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gorosito, Norma Beatriz. Universidad Nacional de Quilmes; ArgentinaFil: Poulsen, Michael. University of Wisconsin; Estados UnidosFil: Currie, Cameron R.. University of Wisconsin; Estados Unido
Towards new literacies and social justice for engineering education
No full textThis paper argues for the need to develop engineering students with high levels of technical competency as well as critical awareness for the realities of working and living ethically in the global community. Drawing on social constructivist principles of learning (Vygotsky, 1978) and a pedagogy of multiliteracies (New London Group, 1996, 2000), the paper explores new approaches for engineering education to meet the challenges embedded in current undergraduate programs and professional accreditation standards. To improve the ability of engineers to contribute to social and environmental justice, there needs to be a rethinking of engineering curriculum and pedagogy to develop engineering literacies that encompass a social and technical focus
Protective Streptomyces in beewolves - Ecology, evolutionary history and specificity of symbiont-mediated defense in Philanthini wasps (Hymenoptera, Crabronidae)
No full textIt is common for animals, plants and fungi to participate in a wide range of associations with microorganisms, and symbioses have been demonstrated to play a crucial role in the evolution of complexity and adaptation for various organisms. Being the most diverse animal class on earth, particularly insects are associated with an extraordinary variety of symbiotic microorganisms. In many insects the symbionts patronize the host´s metabolic potential by producing essential dietary supplements, thereby promoting the survival of their host. However, recent studies yielded evidence that symbiotic microorganisms can play an essential role for the protection of the insect host, its nutritional resources and it´s offspring against pathogenic bacteria and fungi. This thesis investigates the unique symbiotic association of beewolf wasps with antibiotic producing Streptomyces bacteria. Solitary digger wasps of the genera Philanthus, Philanthinus and Trachypus, engage in a unique and highly specific symbiosis with bacteria of the genus Streptomyces that provide protection to the wasp´s progeny. Female wasps cultivate the symbionts in specialized antennal gland reservoirs and secrete them into the subterranean brood cells as a white substance prior to oviposition. Subsequently, they are taken up by the beewolf larva and are incorporated into the silken walls of the cocoon. On the cocoon surface the symbiotic bacteria provide an antimicrobial defense against pathogen infestation by producing a cocktail of different antibiotic substances, thereby significantly enhancing the survival probability of the wasp offspring during their long and vulnerable phase of hibernation
Fig. 1 Sampling strategy for Streptomyces from insect microbiomes. Streptomyces were isolated from a in The antimicrobial potential from insect microbiomes of Streptomyces
No full textFig. 1 Sampling strategy for Streptomyces from insect microbiomes. Streptomyces were isolated from a wide range of insects and geographies (1445 insects; 10,178 strains; dot size, insects sampled). Streptomyces production of the antifungal mycangimycin (1) in the Southern Pine Beetle system is shown at right. Cyphomycin (2) is a new antifungal described herein. Photo credits: southern pine beetle - Erich G. Vallery; fungus-growing ant – Alexander WildPublished as part of Chevrette, Marc G., Carlson, Caitlin M., Ortega, Humberto E., Thomas, Chris, Ananiev, Gene E., Barns, Kenneth J., Book, Adam J., Cagnazzo, Julian, Carlos, Camila, Flanigan, Will, Grubbs, Kirk J., Horn, Heidi A., Hoffmann, Michael, Klassen, Jonathan L., Knack, Jennifer J., Lewin, Gina R., McDonald, Bradon R., Mulle, Laura, Melo, Weilan G.P., Pinto-Tomás, Adrián A., Schmitz, Amber, Wendt-Pienkowski, Evelyn, Wildman, Scott, Zhao, Miao, Zhang, Fan, Bugni, Tim S., Andes, David R., Pupo, Monica T. & Currie, Cameron R., 2019, The antimicrobial potential from insect microbiomes of Streptomyces, pp. 1-11 in Nature Communications 10 (516) on page 2, DOI: 10.1038/s41467-019-08438-0, http://zenodo.org/record/255479
Data Walker 1862
No full textData availability Genomic data can be found at DOI: 10.5281/zenodo.2436565. All other data are available in the main text or the supplementary materials; Permits for collections and accessing genetic resources in Brazil were issued by SISBIO #46555 – 5 and CNPq # 010936 /2014 – 9. Costa Rican collecting permits were issued by the Comisión Institucional de Biodiversidad (Institutional Biodiversity Committee, University of Costa Rica; Resolutions # 0 12 and 020; Material Transfer Agreement MTA VI- 4307 – 2013) and authorized by La Selva Biological Station and Las Brisas Nature Reserve. A modified version of the southern pine beetle (Fig. 1) photo from Erich G. Vallery is used under the Creative Commons Attribution 3.0 License. Photos of Cyphomyrmex (Figs. 1 and 5) are used under a perpetual commercial license from Alexander Wild. Received: 18 October 2018 Accepted: 11 January 2019Published as part of Chevrette, Marc G., Carlson, Caitlin M., Ortega, Humberto E., Thomas, Chris, Ananiev, Gene E., Barns, Kenneth J., Book, Adam J., Cagnazzo, Julian, Carlos, Camila, Flanigan, Will, Grubbs, Kirk J., Horn, Heidi A., Hoffmann, Michael, Klassen, Jonathan L., Knack, Jennifer J., Lewin, Gina R., McDonald, Bradon R., Mulle, Laura, Melo, Weilan G. P., Pinto-Tomás, Adrián A., Schmitz, Amber, Wendt-Pienkowski, Evelyn, Wildman, Scott, Zhao, Miao, Zhang, Fan, Bugni, Tim S., Andes, David R., Pupo, Monica T. & Currie, Cameron R., 2019, The antimicrobial potential from insect microbiomes of Streptomyces, pp. 1-11 in Nature Communications 10 (516) on page 10, DOI: 10.1038/s41467-019-08438-0, http://zenodo.org/record/255479
Fig. 3 in The antimicrobial potential from insect microbiomes of Streptomyces
No full textFig. 3 Bioactivity of insect-associated Streptomyces. a Fungal and b Gram-negative pathogens are significantly more inhibited by insect-associated isolates compared to soil- and plant-sourced Streptomyces (n = 1162, 186, and 178 for insect, soil, and plant, respectively; ***p <1e−3; **p <1e−2; t-test, BY correction). c Strains vary in antimicrobial bioactivity by insect host orders (n = 87, 69, 327, 518, 94, and 39 for Blattodea, Coleoptera, Diptera, Hymenoptera, Lepidoptera, and Orthoptera, respectively). a–c: center, median; box, upper and lower quantiles; notches, 95% confidence; whiskers, 1.5× interquartile range; points, outliers. d Hit rate for insect, soil, and plant strains against individual pathogens (n = 1162, 186, and 178 for insect, soil, and plant, respectively)Published as part of <i>Chevrette, Marc G., Carlson, Caitlin M., Ortega, Humberto E., Thomas, Chris, Ananiev, Gene E., Barns, Kenneth J., Book, Adam J., Cagnazzo, Julian, Carlos, Camila, Flanigan, Will, Grubbs, Kirk J., Horn, Heidi A., Hoffmann, Michael, Klassen, Jonathan L., Knack, Jennifer J., Lewin, Gina R., McDonald, Bradon R., Mulle, Laura, Melo, Weilan G.P., Pinto-Tomás, Adrián A., Schmitz, Amber, Wendt-Pienkowski, Evelyn, Wildman, Scott, Zhao, Miao, Zhang, Fan, Bugni, Tim S., Andes, David R., Pupo, Monica T. & Currie, Cameron R., 2019, The antimicrobial potential from insect microbiomes of Streptomyces, pp. 1-11 in Nature Communications 10 (516)</i> on page 4, DOI: 10.1038/s41467-019-08438-0, <a href="http://zenodo.org/record/2554790">http://zenodo.org/record/2554790</a>
Fig. 4 Ecology and phylogeny influence biosynthetic potential. a A in The antimicrobial potential from insect microbiomes of Streptomyces
No full textFig. 4 Ecology and phylogeny influence biosynthetic potential. a A core-genome phylogeny shows evolutionarily distinct lineages of Streptomyces associate with insects (subset shown, see Supplementary Figure 2). BGC similarity to known BGCs highlights the biosynthetic diversity of insect microbiome strains. b Source invariant (blue) and sub-clade invariant (red) BGC families suggest BGC presence is influenced by both source and phylogeny. LC/MS metabolomics revealed MFs that are unique to c source and d phylogeny. e PCA of the metabolomes identified an outlier strain and f MFs that contribute to its uniqueness, including cyphomycinPublished as part of Chevrette, Marc G., Carlson, Caitlin M., Ortega, Humberto E., Thomas, Chris, Ananiev, Gene E., Barns, Kenneth J., Book, Adam J., Cagnazzo, Julian, Carlos, Camila, Flanigan, Will, Grubbs, Kirk J., Horn, Heidi A., Hoffmann, Michael, Klassen, Jonathan L., Knack, Jennifer J., Lewin, Gina R., McDonald, Bradon R., Mulle, Laura, Melo, Weilan G.P., Pinto-Tomás, Adrián A., Schmitz, Amber, Wendt-Pienkowski, Evelyn, Wildman, Scott, Zhao, Miao, Zhang, Fan, Bugni, Tim S., Andes, David R., Pupo, Monica T. & Currie, Cameron R., 2019, The antimicrobial potential from insect microbiomes of Streptomyces, pp. 1-11 in Nature Communications 10 (516) on page 5, DOI: 10.1038/s41467-019-08438-0, http://zenodo.org/record/255479
Can a winter-sown catch crop reduce nitrate leaching losses after winter forage grazing?
No full textDirect grazing of winter forage crops to feed non-lactating, pregnant dairy cows prior to calving is a common management practice in the New Zealand South Island. However, the high crop yields per hectare grazed, combined with a high stocking density of cows, means this potentially leads to large amounts of urinary nitrogen (N) deposited on bare, wet soil, that in turn, could lead to high nitrate leaching losses. We undertook a study to simulate a winter forage grazing (WFG) event using field lysimeters planted with a kale (Brassica oleracea L.) crop. We report the effect of delaying sowing a “catch crop” of oats (Avena sativa L.) following simulated WFG on nitrate leaching losses from urine applied at different times throughout the winter.
A catch crop sown between 1 and 63 days after urine deposition in early winter reduced N leaching losses from urine patches by ~34% on average (range 19-49%) over the winter-spring period compared with no catch crop. Generally, the sooner the catch crop was sown following crop harvest, the greater the uptake of N by the catch crop and the greater the reduction in nitrate leaching losses.
The results indicate that sowing of a catch crop following winter crop grazing could be an effective management strategy to reduce nitrate leaching as well as increase the N use efficiency of dairy winter forage grazing systems
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