1
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Moulin SLY, Frail S, Braukmann T, Doenier J, Steele-Ogus M, Marks JC, Mills MM, Yeh E. The endosymbiont of Epithemia clementina is specialized for nitrogen fixation within a photosynthetic eukaryote. ISME Commun 2024; 4:ycae055. [PMID: 38707843 PMCID: PMC11070190 DOI: 10.1093/ismeco/ycae055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/05/2024] [Accepted: 04/08/2024] [Indexed: 05/07/2024]
Abstract
Epithemia spp. diatoms contain obligate, nitrogen-fixing endosymbionts, or diazoplasts, derived from cyanobacteria. These algae are a rare example of photosynthetic eukaryotes that have successfully coupled oxygenic photosynthesis with oxygen-sensitive nitrogenase activity. Here, we report a newly-isolated species, E. clementina, as a model to investigate endosymbiotic acquisition of nitrogen fixation. We demonstrate that the diazoplast, which has lost photosynthesis, provides fixed nitrogen to the diatom host in exchange for fixed carbon. To identify the metabolic changes associated with this endosymbiotic specialization, we compared the Epithemia diazoplast with its close, free-living cyanobacterial relative, Crocosphaera subtropica. Unlike C. subtropica, in which nitrogenase activity is temporally separated from photosynthesis, we show that nitrogenase activity in the diazoplast is continuous through the day (concurrent with host photosynthesis) and night. Host and diazoplast metabolism are tightly coupled to support nitrogenase activity: Inhibition of photosynthesis abolishes daytime nitrogenase activity, while nighttime nitrogenase activity no longer requires cyanobacterial glycogen storage pathways. Instead, import of host-derived carbohydrates supports nitrogenase activity throughout the day-night cycle. Carbohydrate metabolism is streamlined in the diazoplast compared to C. subtropica with retention of the oxidative pentose phosphate pathway and oxidative phosphorylation. Similar to heterocysts, these pathways may be optimized to support nitrogenase activity, providing reducing equivalents and ATP and consuming oxygen. Our results demonstrate that the diazoplast is specialized for endosymbiotic nitrogen fixation. Altogether, we establish a new model for studying endosymbiosis, perform a functional characterization of this diazotroph endosymbiosis, and identify metabolic adaptations for endosymbiotic acquisition of a critical biological function.
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Affiliation(s)
- Solène L Y Moulin
- Department of Pathology, Stanford School of Medicine, Stanford, CA 94305, United States
| | - Sarah Frail
- Department of Biochemistry, Stanford School of Medicine, Stanford, CA 94305, United States
| | - Thomas Braukmann
- Department of Pathology, Stanford School of Medicine, Stanford, CA 94305, United States
- Department of Biochemistry, Stanford School of Medicine, Stanford, CA 94305, United States
| | - Jon Doenier
- Department of Biochemistry, Stanford School of Medicine, Stanford, CA 94305, United States
| | - Melissa Steele-Ogus
- Department of Pathology, Stanford School of Medicine, Stanford, CA 94305, United States
| | - Jane C Marks
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AR 86011, United States
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ 86011, United States
| | - Matthew M Mills
- Department of Earth System Science, Stanford Doerr School of Sustainability, Stanford, CA 94305, United States
| | - Ellen Yeh
- Department of Pathology, Stanford School of Medicine, Stanford, CA 94305, United States
- Department of Microbiology & Immunology, Stanford School of Medicine, Stanford, CA 94305, United States
- Chan Zuckerberg Biohub, San Francisco, CA 94158, United States
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2
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Hayer M, Wymore AS, Hungate BA, Schwartz E, Koch BJ, Marks JC. Microbes on decomposing litter in streams: entering on the leaf or colonizing in the water? ISME J 2022; 16:717-725. [PMID: 34580429 PMCID: PMC8857200 DOI: 10.1038/s41396-021-01114-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 08/29/2021] [Accepted: 09/09/2021] [Indexed: 01/04/2023]
Abstract
When leaves fall in rivers, microbial decomposition commences within hours. Microbial assemblages comprising hundreds of species of fungi and bacteria can vary with stream conditions, leaf litter species, and decomposition stage. In terrestrial ecosystems, fungi and bacteria that enter soils with dead leaves often play prominent roles in decomposition, but their role in aquatic decomposition is less known. Here, we test whether fungi and bacteria that enter streams on senesced leaves are growing during decomposition and compare their abundances and growth to bacteria and fungi that colonize leaves in the water. We employ quantitative stable isotope probing to identify growing microbes across four leaf litter species and two decomposition times. We find that most of the growing fungal species on decomposing leaves enter the water with the leaf, whereas most growing bacteria colonize from the water column. Results indicate that the majority of bacteria found on litter are growing, whereas the majority of fungi are dormant. Both bacterial and fungal assemblages differed with leaf type on the dried leaves and throughout decomposition. This research demonstrates the importance of fungal species that enter with the leaf on aquatic decomposition and the prominence of bacteria that colonize decomposing leaves in the water.
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Affiliation(s)
- Michaela Hayer
- Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA.
| | - Adam S. Wymore
- grid.167436.10000 0001 2192 7145Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH 03824 USA
| | - Bruce A. Hungate
- grid.261120.60000 0004 1936 8040Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011 USA
| | - Egbert Schwartz
- grid.261120.60000 0004 1936 8040Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011 USA
| | - Benjamin J. Koch
- grid.261120.60000 0004 1936 8040Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011 USA
| | - Jane C. Marks
- grid.261120.60000 0004 1936 8040Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011 USA
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3
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Purcell AM, Hayer M, Koch BJ, Mau RL, Blazewicz SJ, Dijkstra P, Mack MC, Marks JC, Morrissey EM, Pett‐Ridge J, Rubin RL, Schwartz E, van Gestel NC, Hungate BA. Decreased growth of wild soil microbes after 15 years of transplant-induced warming in a montane meadow. Glob Chang Biol 2022; 28:128-139. [PMID: 34587352 PMCID: PMC9293287 DOI: 10.1111/gcb.15911] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 09/02/2021] [Accepted: 09/09/2021] [Indexed: 05/19/2023]
Abstract
The carbon stored in soil exceeds that of plant biomass and atmospheric carbon and its stability can impact global climate. Growth of decomposer microorganisms mediates both the accrual and loss of soil carbon. Growth is sensitive to temperature and given the vast biological diversity of soil microorganisms, the response of decomposer growth rates to warming may be strongly idiosyncratic, varying among taxa, making ecosystem predictions difficult. Here, we show that 15 years of warming by transplanting plant-soil mesocosms down in elevation, strongly reduced the growth rates of soil microorganisms, measured in the field using undisturbed soil. The magnitude of the response to warming varied among microbial taxa. However, the direction of the response-reduced growth-was universal and warming explained twofold more variation than did the sum of taxonomic identity and its interaction with warming. For this ecosystem, most of the growth responses to warming could be explained without taxon-specific information, suggesting that in some cases microbial responses measured in aggregate may be adequate for climate modeling. Long-term experimental warming also reduced soil carbon content, likely a consequence of a warming-induced increase in decomposition, as warming-induced changes in plant productivity were negligible. The loss of soil carbon and decreased microbial biomass with warming may explain the reduced growth of the microbial community, more than the direct effects of temperature on growth. These findings show that direct and indirect effects of long-term warming can reduce growth rates of soil microbes, which may have important feedbacks to global warming.
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Affiliation(s)
- Alicia M. Purcell
- Department of Biological SciencesCenter for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Michaela Hayer
- Department of Biological SciencesCenter for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Benjamin J. Koch
- Department of Biological SciencesCenter for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Rebecca L. Mau
- Department of Biological SciencesCenter for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Steven J. Blazewicz
- Physical and Life Sciences DirectorateLawrence Livermore National LabLivermoreCaliforniaUSA
| | - Paul Dijkstra
- Department of Biological SciencesCenter for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Michelle C. Mack
- Department of Biological SciencesCenter for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Jane C. Marks
- Department of Biological SciencesCenter for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Ember M. Morrissey
- Division of Plant and Soil SciencesWest Virginia UniversityMorgantownWest VirginiaUSA
| | - Jennifer Pett‐Ridge
- Physical and Life Sciences DirectorateLawrence Livermore National LabLivermoreCaliforniaUSA
- Life & Environmental Sciences DepartmentUniversity of California MercedMercedCAUSA
| | - Rachel L. Rubin
- Department of Environmental SciencesMount Holyoke CollegeSouth HadleyMassachusettsUSA
| | - Egbert Schwartz
- Department of Biological SciencesCenter for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Natasja C. van Gestel
- Department of Biological Sciences & TTU Climate CenterTexas Tech UniversityLubbockTexasUSA
| | - Bruce A. Hungate
- Department of Biological SciencesCenter for Ecosystem Science and SocietyNorthern Arizona UniversityFlagstaffArizonaUSA
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4
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Hungate BA, Marks JC, Power ME, Schwartz E, van Groenigen KJ, Blazewicz SJ, Chuckran P, Dijkstra P, Finley BK, Firestone MK, Foley M, Greenlon A, Hayer M, Hofmockel KS, Koch BJ, Mack MC, Mau RL, Miller SN, Morrissey EM, Propster JR, Purcell AM, Sieradzki E, Starr EP, Stone BWG, Terrer C, Pett-Ridge J. The Functional Significance of Bacterial Predators. mBio 2021; 12:e00466-21. [PMID: 33906922 PMCID: PMC8092244 DOI: 10.1128/mbio.00466-21] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 03/02/2021] [Indexed: 02/07/2023] Open
Abstract
Predation structures food webs, influences energy flow, and alters rates and pathways of nutrient cycling through ecosystems, effects that are well documented for macroscopic predators. In the microbial world, predatory bacteria are common, yet little is known about their rates of growth and roles in energy flows through microbial food webs, in part because these are difficult to quantify. Here, we show that growth and carbon uptake were higher in predatory bacteria compared to nonpredatory bacteria, a finding across 15 sites, synthesizing 82 experiments and over 100,000 taxon-specific measurements of element flow into newly synthesized bacterial DNA. Obligate predatory bacteria grew 36% faster and assimilated carbon at rates 211% higher than nonpredatory bacteria. These differences were less pronounced for facultative predators (6% higher growth rates, 17% higher carbon assimilation rates), though high growth and carbon assimilation rates were observed for some facultative predators, such as members of the genera Lysobacter and Cytophaga, both capable of gliding motility and wolf-pack hunting behavior. Added carbon substrates disproportionately stimulated growth of obligate predators, with responses 63% higher than those of nonpredators for the Bdellovibrionales and 81% higher for the Vampirovibrionales, whereas responses of facultative predators to substrate addition were no different from those of nonpredators. This finding supports the ecological theory that higher productivity increases predator control of lower trophic levels. These findings also indicate that the functional significance of bacterial predators increases with energy flow and that predatory bacteria influence element flow through microbial food webs.IMPORTANCE The word "predator" may conjure images of leopards killing and eating impala on the African savannah or of great white sharks attacking elephant seals off the coast of California. But microorganisms are also predators, including bacteria that kill and eat other bacteria. While predatory bacteria have been found in many environments, it has been challenging to document their importance in nature. This study quantified the growth of predatory and nonpredatory bacteria in soils (and one stream) by tracking isotopically labeled substrates into newly synthesized DNA. Predatory bacteria were more active than nonpredators, and obligate predators, such as Bdellovibrionales and Vampirovibrionales, increased in growth rate in response to added substrates at the base of the food chain, strong evidence of trophic control. This work provides quantitative measures of predator activity and suggests that predatory bacteria-along with protists, nematodes, and phages-are active and important in microbial food webs.
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Affiliation(s)
- Bruce A Hungate
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Jane C Marks
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Mary E Power
- Department of Integrative Biology, University of California Berkeley, Berkeley, California, USA
| | - Egbert Schwartz
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Kees Jan van Groenigen
- Department of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Steven J Blazewicz
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Peter Chuckran
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Paul Dijkstra
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Brianna K Finley
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Mary K Firestone
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, USA
| | - Megan Foley
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Alex Greenlon
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Michaela Hayer
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
| | - Kirsten S Hofmockel
- Pacific Northwest National Laboratory, Richland, Washington, USA
- Department of Agronomy, Iowa State University, Ames, Iowa, USA
| | - Benjamin J Koch
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Michelle C Mack
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Rebecca L Mau
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - Samantha N Miller
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
| | - Ember M Morrissey
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, West Virginia, USA
| | - Jeffrey R Propster
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Alicia M Purcell
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Ella Sieradzki
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, USA
| | - Evan P Starr
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
| | - Bram W G Stone
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, USA
| | - César Terrer
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
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5
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Wang C, Morrissey EM, Mau RL, Hayer M, Piñeiro J, Mack MC, Marks JC, Bell SL, Miller SN, Schwartz E, Dijkstra P, Koch BJ, Stone BW, Purcell AM, Blazewicz SJ, Hofmockel KS, Pett-Ridge J, Hungate BA. The temperature sensitivity of soil: microbial biodiversity, growth, and carbon mineralization. ISME J 2021; 15:2738-2747. [PMID: 33782569 DOI: 10.1038/s41396-021-00959-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/19/2021] [Accepted: 03/04/2021] [Indexed: 11/09/2022]
Abstract
Microorganisms drive soil carbon mineralization and changes in their activity with increased temperature could feedback to climate change. Variation in microbial biodiversity and the temperature sensitivities (Q10) of individual taxa may explain differences in the Q10 of soil respiration, a possibility not previously examined due to methodological limitations. Here, we show phylogenetic and taxonomic variation in the Q10 of growth (5-35 °C) among soil bacteria from four sites, one from each of Arctic, boreal, temperate, and tropical biomes. Differences in the temperature sensitivities of taxa and the taxonomic composition of communities determined community-assembled bacterial growth Q10, which was strongly predictive of soil respiration Q10 within and across biomes. Our results suggest community-assembled traits of microbial taxa may enable enhanced prediction of carbon cycling feedbacks to climate change in ecosystems across the globe.
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Affiliation(s)
- Chao Wang
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV, USA.,CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China
| | - Ember M Morrissey
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV, USA.
| | - Rebecca L Mau
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, USA
| | - Michaela Hayer
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Juan Piñeiro
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV, USA
| | - Michelle C Mack
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Jane C Marks
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Sheryl L Bell
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Samantha N Miller
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Egbert Schwartz
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Paul Dijkstra
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Benjamin J Koch
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Bram W Stone
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Alicia M Purcell
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Steven J Blazewicz
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Kirsten S Hofmockel
- Physical and Life Sciences Directorate, Lawrence Livermore National Lab, Livermore, CA, USA.,Ecology, Evolution and Organismal Biology Department, Iowa State University, Ames, IA, USA
| | - Jennifer Pett-Ridge
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Bruce A Hungate
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
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6
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Abstract
As terrestrial leaf litter decomposes in rivers, its constituent elements follow multiple pathways. Carbon leached as dissolved organic matter can be quickly taken up by microbes, then respired before it can be transferred to the macroscopic food web. Alternatively, this detrital carbon can be ingested and assimilated by aquatic invertebrates, so it is retained longer in the stream and transferred to higher trophic levels. Microbial growth on litter can affect invertebrates through three pathways, which are not mutually exclusive. First, microbes can facilitate invertebrate feeding, improving food quality by conditioning leaves and making them more palatable for invertebrates. Second, microbes can be prey for invertebrates. Third, microbes can compete with invertebrates for resources bound within litter and may produce compounds that retard carbon and nitrogen fluxes to invertebrates. As litter is broken down into smaller particles, there are many opportunities for its elements to reenter the stream food web. Here, I describe a conceptual framework for evaluating how traits of leaf litter will affect its fate in food webs and ecosystems that is useful for predicting how global change will alter carbon fluxes into and out of streams.
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Affiliation(s)
- Jane C. Marks
- Department of Biological Sciences and Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona 86011, USA
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7
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Siders AC, Compson ZG, Hungate BA, Dijkstra P, Koch GW, Wymore AS, Grandy AS, Marks JC. Litter identity affects assimilation of carbon and nitrogen by a shredding caddisfly. Ecosphere 2018. [DOI: 10.1002/ecs2.2340] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Adam C. Siders
- Center for Ecosystem Science and Society; Northern Arizona University; Flagstaff Arizona 86001 USA
- Department of Biological Sciences; Northern Arizona University; Flagstaff Arizona 86011 USA
| | - Zacchaeus G. Compson
- Canadian Rivers Institute; Department of Biology; University of New Brunswick; Fredericton NB E3B 5A3 Canada
- Environment and Climate Change Canada at Canadian Rivers Institute; Department of Biology; University of New Brunswick; Fredericton E3B 5A3 Canada
| | - Bruce A. Hungate
- Center for Ecosystem Science and Society; Northern Arizona University; Flagstaff Arizona 86001 USA
- Department of Biological Sciences; Northern Arizona University; Flagstaff Arizona 86011 USA
| | - Paul Dijkstra
- Center for Ecosystem Science and Society; Northern Arizona University; Flagstaff Arizona 86001 USA
- Department of Biological Sciences; Northern Arizona University; Flagstaff Arizona 86011 USA
| | - George W. Koch
- Center for Ecosystem Science and Society; Northern Arizona University; Flagstaff Arizona 86001 USA
- Department of Biological Sciences; Northern Arizona University; Flagstaff Arizona 86011 USA
| | - Adam S. Wymore
- Department of Natural Resources and the Environment; University of New Hampshire; Durham New Hampshire 03824 USA
| | - A. Stuart Grandy
- Department of Natural Resources and the Environment; University of New Hampshire; Durham New Hampshire 03824 USA
| | - Jane C. Marks
- Center for Ecosystem Science and Society; Northern Arizona University; Flagstaff Arizona 86001 USA
- Department of Biological Sciences; Northern Arizona University; Flagstaff Arizona 86011 USA
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8
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Compson ZG, Hungate BA, Whitham TG, Koch GW, Dijkstra P, Siders AC, Wojtowicz T, Jacobs R, Rakestraw DN, Allred KE, Sayer CK, Marks JC. Linking tree genetics and stream consumers: isotopic tracers elucidate controls on carbon and nitrogen assimilation. Ecology 2018; 99:1759-1770. [DOI: 10.1002/ecy.2224] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 01/30/2018] [Accepted: 02/09/2018] [Indexed: 12/27/2022]
Affiliation(s)
- Zacchaeus G. Compson
- Center for Ecosystem Science and Society; 800 S. Beaver Street, P.O. Box 5620 Flagstaff Arizona 86011-5620 USA
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
| | - Bruce A. Hungate
- Center for Ecosystem Science and Society; 800 S. Beaver Street, P.O. Box 5620 Flagstaff Arizona 86011-5620 USA
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
| | - Thomas G. Whitham
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
| | - George W. Koch
- Center for Ecosystem Science and Society; 800 S. Beaver Street, P.O. Box 5620 Flagstaff Arizona 86011-5620 USA
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
| | - Paul Dijkstra
- Center for Ecosystem Science and Society; 800 S. Beaver Street, P.O. Box 5620 Flagstaff Arizona 86011-5620 USA
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
| | - Adam C. Siders
- Center for Ecosystem Science and Society; 800 S. Beaver Street, P.O. Box 5620 Flagstaff Arizona 86011-5620 USA
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
| | - Todd Wojtowicz
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
| | - Ryan Jacobs
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
| | - David N. Rakestraw
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
| | - Kiel E. Allred
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
| | - Chelsea K. Sayer
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
| | - Jane C. Marks
- Center for Ecosystem Science and Society; 800 S. Beaver Street, P.O. Box 5620 Flagstaff Arizona 86011-5620 USA
- Merriam-Powell Center for Environmental Research; 800 S. Beaver Street, P.O. Box 6077 Flagstaff Arizona 86011-6077 USA
- Department of Biological Sciences; Northern Arizona University; 617 S. Beaver Street, P.O. Box 5640 Flagstaff Arizona 86011-5640 USA
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9
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Sabo JL, Caron M, Doucett R, Dibble KL, Ruhi A, Marks JC, Hungate BA, Kennedy TA. Pulsed flows, tributary inputs and food-web structure in a highly regulated river. J Appl Ecol 2018. [DOI: 10.1111/1365-2664.13109] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- John L. Sabo
- Julie Ann Wrigley Global Institute of Sustainability; Arizona State University; Tempe AZ USA
- School of Life Sciences; Arizona State University; Tempe AZ USA
| | - Melanie Caron
- Colorado Plateau Stable Isotope Laboratory; Northern Arizona University; Flagstaff AZ USA
- Center for Ecosystem Science and Society; Northern Arizona University; Flagstaff AZ USA
| | - Rick Doucett
- Colorado Plateau Stable Isotope Laboratory; Northern Arizona University; Flagstaff AZ USA
- Rick Doucett, Department of Plant Sciences; UC Davis Stable Isotope Facility; Room 1210 PES One Shields Avenue Davis CA USA
| | - Kimberly L. Dibble
- U.S. Geological Survey; Southwest Biological Science Center; Grand Canyon Monitoring and Research Center; Flagstaff AZ USA
| | - Albert Ruhi
- Julie Ann Wrigley Global Institute of Sustainability; Arizona State University; Tempe AZ USA
| | - Jane C. Marks
- Department of Biological Sciences; Northern Arizona University. Flagstaff; AZ USA
| | - Bruce A. Hungate
- Colorado Plateau Stable Isotope Laboratory; Northern Arizona University; Flagstaff AZ USA
- Center for Ecosystem Science and Society; Northern Arizona University; Flagstaff AZ USA
| | - Ted A. Kennedy
- U.S. Geological Survey; Southwest Biological Science Center; Grand Canyon Monitoring and Research Center; Flagstaff AZ USA
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10
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Koch BJ, McHugh TA, Hayer M, Schwartz E, Blazewicz SJ, Dijkstra P, Gestel N, Marks JC, Mau RL, Morrissey EM, Pett‐Ridge J, Hungate BA. Estimating taxon‐specific population dynamics in diverse microbial communities. Ecosphere 2018. [DOI: 10.1002/ecs2.2090] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Benjamin J. Koch
- Center for Ecosystem Science and Society Northern Arizona University Flagstaff Arizona 86011 USA
| | - Theresa A. McHugh
- Center for Ecosystem Science and Society Northern Arizona University Flagstaff Arizona 86011 USA
| | - Michaela Hayer
- Center for Ecosystem Science and Society Northern Arizona University Flagstaff Arizona 86011 USA
| | - Egbert Schwartz
- Center for Ecosystem Science and Society Northern Arizona University Flagstaff Arizona 86011 USA
- Department of Biological Sciences Northern Arizona University Flagstaff Arizona 86011 USA
| | - Steven J. Blazewicz
- Physical and Life Sciences Directorate Lawrence Livermore National Laboratory Livermore California 94550 USA
| | - Paul Dijkstra
- Center for Ecosystem Science and Society Northern Arizona University Flagstaff Arizona 86011 USA
- Department of Biological Sciences Northern Arizona University Flagstaff Arizona 86011 USA
| | - Natasja Gestel
- Center for Ecosystem Science and Society Northern Arizona University Flagstaff Arizona 86011 USA
| | - Jane C. Marks
- Center for Ecosystem Science and Society Northern Arizona University Flagstaff Arizona 86011 USA
- Department of Biological Sciences Northern Arizona University Flagstaff Arizona 86011 USA
| | - Rebecca L. Mau
- Center for Ecosystem Science and Society Northern Arizona University Flagstaff Arizona 86011 USA
| | - Ember M. Morrissey
- Division of Plant and Soil Sciences West Virginia University Morgantown West Virginia 26506 USA
| | - Jennifer Pett‐Ridge
- Physical and Life Sciences Directorate Lawrence Livermore National Laboratory Livermore California 94550 USA
| | - Bruce A. Hungate
- Center for Ecosystem Science and Society Northern Arizona University Flagstaff Arizona 86011 USA
- Department of Biological Sciences Northern Arizona University Flagstaff Arizona 86011 USA
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11
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Morrissey EM, Mau RL, Schwartz E, McHugh TA, Dijkstra P, Koch BJ, Marks JC, Hungate BA. Bacterial carbon use plasticity, phylogenetic diversity and the priming of soil organic matter. ISME J 2017; 11:1890-1899. [PMID: 28387774 DOI: 10.1038/ismej.2017.43] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 02/06/2017] [Accepted: 02/14/2017] [Indexed: 12/26/2022]
Abstract
Microorganisms perform most decomposition on Earth, mediating carbon (C) loss from ecosystems, and thereby influencing climate. Yet, how variation in the identity and composition of microbial communities influences ecosystem C balance is far from clear. Using quantitative stable isotope probing of DNA, we show how individual bacterial taxa influence soil C cycling following the addition of labile C (glucose). Specifically, we show that increased decomposition of soil C in response to added glucose (positive priming) occurs as a phylogenetically diverse group of taxa, accounting for a large proportion of the bacterial community, shift toward additional soil C use for growth. Our findings suggest that many microbial taxa exhibit C use plasticity, as most taxa altered their use of glucose and soil organic matter depending upon environmental conditions. In contrast, bacteria that exhibit other responses to glucose (reduced growth or reliance on glucose for additional growth) clustered strongly by phylogeny. These results suggest that positive priming is likely the prototypical response of bacteria to sustained labile C addition, consistent with the widespread occurrence of the positive priming effect in nature.
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Affiliation(s)
- Ember M Morrissey
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV, USA
| | - Rebecca L Mau
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Egbert Schwartz
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Theresa A McHugh
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Colorado Mesa University, Grand Junction, CO, USA
| | - Paul Dijkstra
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Benjamin J Koch
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Jane C Marks
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Bruce A Hungate
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
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12
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Hayer M, Schwartz E, Marks JC, Koch BJ, Morrissey EM, Schuettenberg AA, Hungate BA. Identification of growing bacteria during litter decomposition in freshwater through H218O quantitative stable isotope probing. Environ Microbiol Rep 2016; 8:975-982. [PMID: 27657357 DOI: 10.1111/1758-2229.12475] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 09/15/2016] [Indexed: 06/06/2023]
Abstract
Identification of microorganisms that facilitate the cycling of nutrients in freshwater is paramount to understanding how these ecosystems function. Here, we identify growing aquatic bacteria using H218O quantitative stable isotope probing. During 8 day incubations in 97 atom % H218O, 54% of the taxa grew. The most abundant phyla among growing taxa were Proteobacteria (45%), Bacteroidetes (30%) and Firmicutes (10%). Taxa differed in isotopic enrichment, reflecting variation in DNA replication of bacterial populations. At the class level, the highest atom fraction excess was observed for OPB41 and δ-Proteobacteria. There was no linear relationship between 18 O incorporation and abundance of taxa. δ-Proteobacteria and OPB41 were not abundant, yet the DNA of both taxa was highly enriched in 18 O. Bacteriodetes, in contrast, were abundant but not highly enriched. Our study shows that a large proportion of the bacterial taxa found on decomposing leaf litter grew slowly, and several low abundance taxa were highly enriched. These findings indicating that rare organisms may be important for the decomposition of leaf litter in streams, and that quantitative stable isotope probing with H218O can be used to advance our understanding of microorganisms in freshwater by identifying species that are growing in complex communities.
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Affiliation(s)
- Michaela Hayer
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Egbert Schwartz
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86001, USA
| | - Jane C Marks
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86001, USA
| | - Benjamin J Koch
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Ember M Morrissey
- Division of Plant and Soil, West Virginia University, Morgantown, WV, 26506, USA
| | - Alexa A Schuettenberg
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86001, USA
| | - Bruce A Hungate
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86001, USA
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13
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Wymore AS, Liu CM, Hungate BA, Schwartz E, Price LB, Whitham TG, Marks JC. The Influence of Time and Plant Species on the Composition of the Decomposing Bacterial Community in a Stream Ecosystem. Microb Ecol 2016; 71:825-834. [PMID: 26879940 DOI: 10.1007/s00248-016-0735-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Accepted: 01/31/2016] [Indexed: 06/05/2023]
Abstract
Foliar chemistry influences leaf decomposition, but little is known about how litter chemistry affects the assemblage of bacterial communities during decomposition. Here we examined relationships between initial litter chemistry and the composition of the bacterial community in a stream ecosystem. We incubated replicated genotypes of Populus fremontii and P. angustifolia leaf litter that differ in percent tannin and lignin, then followed changes in bacterial community composition during 28 days of decomposition using 16S rRNA gene-based pyrosequencing. Using a nested experimental design, the majority of variation in bacterial community composition was explained by time (i.e., harvest day) (R(2) = 0.50). Plant species, nested within harvest date, explained a significant but smaller proportion of the variation (R(2) = 0.03). Significant differences in community composition between leaf species were apparent at day 14, but no significant differences existed among genotypes. Foliar chemistry correlated significantly with community composition at day 14 (r = 0.46) indicating that leaf litter with more similar phytochemistry harbor bacterial communities that are alike. Bacteroidetes and β-proteobacteria dominated the bacterial assemblage on decomposing leaves, and Verrucomicrobia and α- and δ-proteobacteria became more abundant over time. After 14 days, bacterial diversity diverged significantly between leaf litter types with fast-decomposing P. fremontii hosting greater richness than slowly decomposing P. angustifolia; however, differences were no longer present after 28 days in the stream. Leaf litter tannin, lignin, and lignin: N ratios all correlated negatively with diversity. This work shows that the bacterial community on decomposing leaves in streams changes rapidly over time, influenced by leaf species via differences in genotype-level foliar chemistry.
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Affiliation(s)
- Adam S Wymore
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA.
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, USA.
| | - Cindy M Liu
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
- Translational Genomics Research Institute, Flagstaff, AZ, USA
| | - Bruce A Hungate
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Egbert Schwartz
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Lance B Price
- Translational Genomics Research Institute, Flagstaff, AZ, USA
- School of Public Health and Health Services, George Washington University, Washington, D.C., USA
| | - Thomas G Whitham
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Jane C Marks
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
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14
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Morrissey EM, Mau RL, Schwartz E, Caporaso JG, Dijkstra P, van Gestel N, Koch BJ, Liu CM, Hayer M, McHugh TA, Marks JC, Price LB, Hungate BA. Phylogenetic organization of bacterial activity. ISME J 2016; 10:2336-40. [PMID: 26943624 PMCID: PMC4989319 DOI: 10.1038/ismej.2016.28] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/14/2016] [Accepted: 01/18/2016] [Indexed: 11/25/2022]
Abstract
Phylogeny is an ecologically meaningful way to classify plants and animals, as closely related taxa frequently have similar ecological characteristics, functional traits and effects on ecosystem processes. For bacteria, however, phylogeny has been argued to be an unreliable indicator of an organism's ecology owing to evolutionary processes more common to microbes such as gene loss and lateral gene transfer, as well as convergent evolution. Here we use advanced stable isotope probing with 13C and 18O to show that evolutionary history has ecological significance for in situ bacterial activity. Phylogenetic organization in the activity of bacteria sets the stage for characterizing the functional attributes of bacterial taxonomic groups. Connecting identity with function in this way will allow scientists to begin building a mechanistic understanding of how bacterial community composition regulates critical ecosystem functions.
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Affiliation(s)
- Ember M Morrissey
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Rebecca L Mau
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Egbert Schwartz
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - J Gregory Caporaso
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA.,Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, USA
| | - Paul Dijkstra
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Natasja van Gestel
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Benjamin J Koch
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Cindy M Liu
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, USA.,Center for Microbiomics and Human Health, Translational Genomics Research Institute, Flagstaff, AZ, USA.,Department of Environmental and Occupational Health, Milken Institute School of Public Health, George Washington University, Washington, DC, USA
| | - Michaela Hayer
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Theresa A McHugh
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Jane C Marks
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Lance B Price
- Center for Microbiomics and Human Health, Translational Genomics Research Institute, Flagstaff, AZ, USA.,Department of Environmental and Occupational Health, Milken Institute School of Public Health, George Washington University, Washington, DC, USA
| | - Bruce A Hungate
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
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15
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Mau RL, Liu CM, Aziz M, Schwartz E, Dijkstra P, Marks JC, Price LB, Keim P, Hungate BA. Linking soil bacterial biodiversity and soil carbon stability. ISME J 2014; 9:1477-80. [PMID: 25350158 DOI: 10.1038/ismej.2014.205] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 09/05/2014] [Accepted: 09/22/2014] [Indexed: 10/24/2022]
Abstract
Native soil carbon (C) can be lost in response to fresh C inputs, a phenomenon observed for decades yet still not understood. Using dual-stable isotope probing, we show that changes in the diversity and composition of two functional bacterial groups occur with this 'priming' effect. A single-substrate pulse suppressed native soil C loss and reduced bacterial diversity, whereas repeated substrate pulses stimulated native soil C loss and increased diversity. Increased diversity after repeated C amendments contrasts with resource competition theory, and may be explained by increased predation as evidenced by a decrease in bacterial 16S rRNA gene copies. Our results suggest that biodiversity and composition of the soil microbial community change in concert with its functioning, with consequences for native soil C stability.
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Affiliation(s)
- Rebecca L Mau
- 1] Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA [2] Center for Ecosystem Science and Society (Ecoss), Northern Arizona University, Flagstaff, AZ, USA
| | - Cindy M Liu
- 1] Translational Genomics Research Institute (TGen North), Flagstaff, AZ, USA [2] Microbial Genetic and Genomics Center (MGGen), Northern Arizona University, Flagstaff, AZ, USA
| | - Maliha Aziz
- Translational Genomics Research Institute (TGen North), Flagstaff, AZ, USA
| | - Egbert Schwartz
- 1] Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA [2] Center for Ecosystem Science and Society (Ecoss), Northern Arizona University, Flagstaff, AZ, USA
| | - Paul Dijkstra
- 1] Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA [2] Center for Ecosystem Science and Society (Ecoss), Northern Arizona University, Flagstaff, AZ, USA
| | - Jane C Marks
- 1] Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA [2] Center for Ecosystem Science and Society (Ecoss), Northern Arizona University, Flagstaff, AZ, USA
| | - Lance B Price
- Translational Genomics Research Institute (TGen North), Flagstaff, AZ, USA
| | - Paul Keim
- 1] Center for Ecosystem Science and Society (Ecoss), Northern Arizona University, Flagstaff, AZ, USA [2] Translational Genomics Research Institute (TGen North), Flagstaff, AZ, USA [3] Microbial Genetic and Genomics Center (MGGen), Northern Arizona University, Flagstaff, AZ, USA
| | - Bruce A Hungate
- 1] Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA [2] Center for Ecosystem Science and Society (Ecoss), Northern Arizona University, Flagstaff, AZ, USA
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16
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Pastor A, Compson ZG, Dijkstra P, Riera JL, Martí E, Sabater F, Hungate BA, Marks JC. Stream carbon and nitrogen supplements during leaf litter decomposition: contrasting patterns for two foundation species. Oecologia 2014; 176:1111-21. [PMID: 25214242 DOI: 10.1007/s00442-014-3063-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 08/21/2014] [Indexed: 11/28/2022]
Abstract
Leaf litter decomposition plays a major role in nutrient dynamics in forested streams. The chemical composition of litter affects its processing by microorganisms, which obtain nutrients from litter and from the water column. The balance of these fluxes is not well known, because they occur simultaneously and thus are difficult to quantify separately. Here, we examined C and N flow from streamwater and leaf litter to microbial biofilms during decomposition. We used isotopically enriched leaves ((13)C and (15)N) from two riparian foundation tree species: fast-decomposing Populus fremontii and slow-decomposing Populus angustifolia, which differed in their concentration of recalcitrant compounds. We adapted the isotope pool dilution method to estimate gross elemental fluxes into litter microbes. Three key findings emerged: litter type strongly affected biomass and stoichiometry of microbial assemblages growing on litter; the proportion of C and N in microorganisms derived from the streamwater, as opposed to the litter, did not differ between litter types, but increased throughout decomposition; gross immobilization of N from the streamwater was higher for P. fremontii compared to P. angustifolia, probably as a consequence of the higher microbial biomass on P. fremontii. In contrast, gross immobilization of C from the streamwater was higher for P. angustifolia, suggesting that dissolved organic C in streamwater was used as an additional energy source by microbial assemblages growing on slow-decomposing litter. These results indicate that biofilms on decomposing litter have specific element requirements driven by litter characteristics, which might have implications for whole-stream nutrient retention.
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Affiliation(s)
- Ada Pastor
- Department d'Ecologia, Universitat de Barcelona, Barcelona, Spain,
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17
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Millman JM, Waits K, Grande H, Marks AR, Marks JC, Price LB, Hungate BA. Prevalence of antibiotic-resistant E. coli in retail chicken: comparing conventional, organic, kosher, and raised without antibiotics. F1000Res 2013; 2:155. [PMID: 24555073 PMCID: PMC3901448 DOI: 10.12688/f1000research.2-155.v2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/29/2013] [Indexed: 01/24/2023] Open
Abstract
Retail poultry products are known sources of antibiotic-resistant Escherichia coli, a major human health concern. Consumers have a range of choices for poultry, including conventional, organic, kosher, and raised without antibiotics (RWA) - designations that are perceived to indicate differences in quality and safety. However, whether these categories vary in the frequency of contamination with antibiotic-resistant E. coli is unknown. We examined the occurrence of antibiotic-resistant E. coli on raw chicken marketed as conventional, organic, kosher and RWA. From April - June 2012, we purchased 213 samples of raw chicken from 15 locations in the New York City metropolitan area. We screened E. coli isolates from each sample for resistance to 12 common antibiotics. Although the organic and RWA labels restrict the use of antibiotics, the frequency of antibiotic-resistant E. coli tended to be only slightly lower for RWA, and organic chicken was statistically indistinguishable from conventional products that have no restrictions. Kosher chicken had the highest frequency of antibiotic-resistant E. coli, nearly twice that of conventional products, a result that belies the historical roots of kosher as a means to ensure food safety. These results indicate that production methods influence the frequency of antibiotic-resistant E. coli on poultry products available to consumers. Future research to identify the specific practices that cause the high frequency of antibiotic-resistant E. coli in kosher chicken could promote efforts to reduce consumer exposure to this potential pathogen.
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Affiliation(s)
| | - Kara Waits
- Translational Genomics Research Institute, Flagstaff AZ, 86001, USA
| | - Heidi Grande
- Translational Genomics Research Institute, Flagstaff AZ, 86001, USA
| | - Ann R Marks
- Horace Mann Bronx Campus, Bronx NY, 10471, USA
| | - Jane C Marks
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff AZ, 86011, USA
| | - Lance B Price
- Department of Environmental and Occupational Health, George Washington University, Washington DC, 20037, USA
| | - Bruce A Hungate
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff AZ, 86011, USA
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18
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Millman JM, Waits K, Grande H, Marks AR, Marks JC, Price LB, Hungate BA. Prevalence of antibiotic-resistant E. coli in retail chicken: comparing conventional, organic, kosher, and raised without antibiotics. F1000Res 2013; 2:155. [PMID: 24555073 PMCID: PMC3901448 DOI: 10.12688/f1000research.2-155.v1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/29/2013] [Indexed: 09/17/2023] Open
Abstract
Retail poultry products are known sources of antibiotic-resistant Escherichia coli, a major human health concern. Consumers have a range of choices for poultry, including conventional, organic, kosher, and raised without antibiotics (RWA) - designations that are perceived to indicate differences in quality and safety. However, whether these categories vary in the frequency of contamination with antibiotic-resistant E. coli is unknown. We examined the occurrence of antibiotic-resistant E. coli on raw chicken marketed as conventional, organic, kosher and RWA. From April - June 2012, we purchased 213 samples of raw chicken from 15 locations in the New York City metropolitan area. We screened E. coli isolates from each sample for resistance to 12 common antibiotics. Although the organic and RWA labels restrict the use of antibiotics, the frequency of antibiotic-resistant E. coli tended to be only slightly lower for RWA, and organic chicken was statistically indistinguishable from conventional products that have no restrictions. Kosher chicken had the highest frequency of antibiotic-resistant E. coli, nearly twice that of conventional products, a result that belies the historical roots of kosher as a means to ensure food safety. These results indicate that production methods influence the frequency of antibiotic-resistant E. coli on poultry products available to consumers. Future research to identify the specific practices that cause the high frequency of antibiotic-resistant E. coli in kosher chicken could promote efforts to reduce consumer exposure to this potential pathogen.
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Affiliation(s)
| | - Kara Waits
- Translational Genomics Research Institute, Flagstaff AZ, 86001, USA
| | - Heidi Grande
- Translational Genomics Research Institute, Flagstaff AZ, 86001, USA
| | - Ann R Marks
- Horace Mann Bronx Campus, Bronx NY, 10471, USA
| | - Jane C Marks
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff AZ, 86011, USA
| | - Lance B Price
- Department of Environmental and Occupational Health, George Washington University, Washington DC, 20037, USA
| | - Bruce A Hungate
- Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff AZ, 86011, USA
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19
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Muhamat Nor FE, Chandrasekaran K, Marks JC. A retrospective audit of 200 cases of CNS tumours and their surgical management in a tertiary care centre. Ir J Med Sci 2013; 182:697-701. [PMID: 23645548 DOI: 10.1007/s11845-013-0959-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 04/22/2013] [Indexed: 10/26/2022]
Abstract
AIMS To study the nature of the tumours managed in the Irish population. METHODS This audit research was completed via a retrospective medical review on 200 patients with CNS tumours managed in a tertiary care centre between 2008 and 2009. RESULTS The mean age was 53 years. The male:female ratio was 2:1. The majority were glioblastomas and astrocytomas. Grade IV tumours were predominant (65.5 %). Headaches (37 %), motor weakness (32 %) and seizures (25.5 %) were the highest presentations. The commonest sites affected were the left parietal and left temporal lobes. There were 17.5 % operative morbidities with motor weakness (22.9 %), seizure (14.3 %) and thrombo-embolism (14.3 %) dominating and significant association to surgical radicality (p = 0.041). 3.5 % operative mortalities were reported. 52.5 and 62.5 % of patients received adjuvant chemotherapy and radiotherapy, respectively. CONCLUSIONS Patients with CNS tumours typically had multiple presentations. More extensive surgical resection was associated with higher postoperative morbidities (p = 0.041). The 30-day postoperative morbidity (17.5 %) and mortality (3.5 %) were concordant with the currently available literature.
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Affiliation(s)
- F E Muhamat Nor
- Department of Neurosurgery, Cork University Hospital, Wilton, Cork, Republic of Ireland,
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20
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Compson ZG, Adams KJ, Edwards JA, Maestas JM, Whitham TG, Marks JC. Leaf litter quality affects aquatic insect emergence: contrasting patterns from two foundation trees. Oecologia 2013; 173:507-19. [PMID: 23532583 DOI: 10.1007/s00442-013-2643-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 03/07/2013] [Indexed: 10/27/2022]
Abstract
Reciprocal subsidies between rivers and terrestrial habitats are common where terrestrial leaf litter provides energy to aquatic invertebrates while emerging aquatic insects provide energy to terrestrial predators (e.g., birds, lizards, spiders). We examined how aquatic insect emergence changed seasonally with litter from two foundation riparian trees, whose litter often dominates riparian streams of the southwestern United States: Fremont (Populus fremontii) and narrowleaf (Populus angustifolia) cottonwood. P. fremontii litter is fast-decomposing and lower in defensive phytochemicals (i.e., condensed tannins, lignin) relative to P. angustifolia. We experimentally manipulated leaf litter from these two species by placing them in leaf enclosures with emergence traps attached in order to determine how leaf type influenced insect emergence. Contrary to our initial predictions, we found that packs with slow-decomposing leaves tended to support more emergent insects relative to packs with fast-decomposing leaves. Three findings emerged. Firstly, abundance (number of emerging insects m(-2) day(-1)) was 25% higher on narrowleaf compared to Fremont leaves for the spring but did not differ in the fall, demonstrating that leaf quality from two dominant trees of the same genus yielded different emergence patterns and that these patterns changed seasonally. Secondly, functional feeding groups of emerging insects differed between treatments and seasons. Specifically, in the spring collector-gatherer abundance and biomass were higher on narrowleaf leaves, whereas collector-filterer abundance and biomass were higher on Fremont leaves. Shredder abundance and biomass were higher on narrowleaf leaves in the fall. Thirdly, diversity (Shannon's H') was higher on Fremont leaves in the spring, but no differences were found in the fall, showing that fast-decomposing leaves can support a more diverse, complex emergent insect assemblage during certain times of the year. Collectively, these results challenge the notion that leaf quality is a simple function of decomposition, suggesting instead that aquatic insects benefit differentially from different leaf types, such that some use slow-decomposing litter for habitat and its temporal longevity and others utilize fast-decomposing litter with more immediate nutrient release.
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Affiliation(s)
- Zacchaeus G Compson
- Merriam-Powell Center for Environmental Research, Department of Biological Sciences, Northern Arizona University, 617 S. Beaver St., P. O. Box 5640, Flagstaff, AZ, 86011-5640, USA,
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O'Grady I, McCarthy C, Kaliaperumal C, Marks JC, Kaar G, O'Sullivan M. Are we justified in doing blood tests 'routinely' for all neurosurgical patients? Ir Med J 2013; 106:18-20. [PMID: 23472371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
To ensure continuing patient care in a cost effective and efficient manner and to determine the importance of routine pre-op bloods in patients undergoing spine surgery, a retrospective audit of 170 patients was carried out in the Neurosurgery Department at Cork University Hospital. There were 94 males and 76 females. No test had less than 87.4% normal results. There were 17 (10.7%) abnormal haemoglobin levels, 13 (8.2%) abnormal white cell count levels, 14 (8.9%) abnormal creatinine levels and of sodium and potassium levels, 5 (3.2%) and 3 (2%) were abnormal respectively. Of the abnormal results, the majority fell close to reference range. 95% of the total cost incurred in performing the procedure was attributed to normal blood results. Abnormal blood results in this cohort of patients did not alter management. We conclude that routine blood tests, including coagulation screen, may not be necessary in healthy individuals undergoing elective spine surgery.
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Affiliation(s)
- I O'Grady
- Neurosurgery Department, Cork University Hospital, Wilton, Cork.
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Avery LA, Ward DL, Marks JC. Exercise Conditioning Decreases Downstream Movement of Pond-Reared Razorback Suckers Released Into a Stream Environment. WEST N AM NATURALIST 2011. [DOI: 10.3398/064.071.0111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Marks JC, Haden GA, O’Neill M, Pace C. Effects of Flow Restoration and Exotic Species Removal on Recovery of Native Fish: Lessons from a Dam Decommissioning. Restor Ecol 2009. [DOI: 10.1111/j.1526-100x.2009.00574.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Aquilina K, Kamel M, Kalimuthu SG, Marks JC, Keohane C. Granular cell tumour of the neurohypophysis: a rare sellar tumour with specific radiological and operative features. Br J Neurosurg 2009; 20:51-4. [PMID: 16698612 DOI: 10.1080/02688690600600996] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Symptomatic granular cell tumours of the neurohypophysis are rare sellar lesions. Preoperative prediction of the diagnosis on the basis of radiological appearance is useful as these tumours carry specific surgical difficulties. This is possible when the tumour arises from the pituitary stalk, rostral to a normal pituitary gland. This has not been emphasized previously.
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Affiliation(s)
- K Aquilina
- Department of Neurosurgery, Cork University Hospital, Wilton, Cork, Republic of Ireland.
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Affiliation(s)
- Brenda L. Harrop
- Department of Biological Sciences, Northern Arizona University, PO Box 5640, Flagstaff, Arizona 86011-5640 USA
| | - Jane C. Marks
- Department of Biological Sciences, Northern Arizona University, PO Box 5640, Flagstaff, Arizona 86011-5640 USA
| | - Mary E. Watwood
- Department of Biological Sciences, Northern Arizona University, PO Box 5640, Flagstaff, Arizona 86011-5640 USA
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LeRoy CJ, Whitham TG, Wooley SC, Marks JC. Within-species variation in foliar chemistry influences leaf-litter decomposition in a Utah river. ACTA ACUST UNITED AC 2007. [DOI: 10.1899/06-113.1] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Carri J. LeRoy
- Lab II 3261, The Evergreen State College, 2700 Evergreen Parkway NW, Olympia, Washington 98505 USA
| | - Thomas G. Whitham
- Department of Biological Sciences, Northern Arizona University, PO Box 5640, Flagstaff, Arizona 86011 USA
| | - Stuart C. Wooley
- Department of Entomology, 1630 Linden Drive, University of Wisconsin, Madison, Wisconsin 53706 USA
| | - Jane C. Marks
- Department of Biological Sciences, Northern Arizona University, PO Box 5640, Flagstaff, Arizona 86011 USA
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Abstract
Understanding river food webs requires distinguishing energy derived from primary production in the river itself (autochthonous) from that produced externally (allochthonous), yet there are no universally applicable and reliable techniques for doing so. We compared the natural abundance stable isotope ratios of hydrogen (deltaD) of allochthonous and autochthonous energy sources in four different aquatic ecosystems. We found that autochthonous organic matter is uniformly far more depleted in deuterium (lower deltaD values) than allochthonous: an average difference of approximately 100% per hundred. We also found that organisms at higher trophic levels, including both aquatic invertebrates and fish, have deltaD values intermediate between aquatic algae and terrestrial plants. The consistent differences between leaves and algae in deltaD among these four watersheds, along with the intermediate values in higher trophic levels, indicate that natural abundance hydrogen isotope signatures are a powerful tool for partitioning energy flow in aquatic ecosystems.
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Affiliation(s)
- Richard R Doucett
- Colorado Plateau Stable Isotope Laboratory, Northern Arizona University, Flagstaff, Arizona 86011, USA
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Marks JC. Down go the dams. Many dams are being torn down these days, allowing rivers and the ecosystems they support to rebound. But ecological risks abound as well. Can they be averted? Sci Am 2007; 296:66-71. [PMID: 17348161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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Whitham TG, Bailey JK, Schweitzer JA, Shuster SM, Bangert RK, LeRoy CJ, Lonsdorf EV, Allan GJ, DiFazio SP, Potts BM, Fischer DG, Gehring CA, Lindroth RL, Marks JC, Hart SC, Wimp GM, Wooley SC. A framework for community and ecosystem genetics: from genes to ecosystems. Nat Rev Genet 2006; 7:510-23. [PMID: 16778835 DOI: 10.1038/nrg1877] [Citation(s) in RCA: 589] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Can heritable traits in a single species affect an entire ecosystem? Recent studies show that such traits in a common tree have predictable effects on community structure and ecosystem processes. Because these 'community and ecosystem phenotypes' have a genetic basis and are heritable, we can begin to apply the principles of population and quantitative genetics to place the study of complex communities and ecosystems within an evolutionary framework. This framework could allow us to understand, for the first time, the genetic basis of ecosystem processes, and the effect of such phenomena as climate change and introduced transgenic organisms on entire communities.
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Affiliation(s)
- Thomas G Whitham
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona 86011, USA.
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Abstract
Although it is understood that the composition of riparian trees can affect stream function through leaf litter fall, the potential effects of genetic variation within species are less understood. Using a naturally hybridizing cottonwood system, we examined the hypothesis that genetic differences among two parental species (Populus fremontii and P. angustifolia) and two groups of their hybrids (F1 and backcrosses to P. angustifolia) would affect litter decomposition rates and the composition of the aquatic invertebrate community that colonizes leaves. Three major findings emerged: (1) parental and hybrid types differ in litter quality, (2) decomposition differs between two groups, a fast group (P. fremontii and F1 hybrid), and a slow group (P. angustifolia and backcross hybrids), and (3) aquatic invertebrate communities colonizing P. fremontii litter differed significantly in composition from all other cross types, even though P. fremontii and the F1 hybrid decomposed at similar rates. These findings are in agreement with terrestrial arthropod studies in the same cottonwood system. However, the effects are less pronounced aquatically than those observed in the adjacent terrestrial community, which supports a genetic diffusion hypothesis. Importantly, these findings argue that genetic interactions link terrestrial and aquatic communities and may have significant evolutionary and conservation implications.
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Affiliation(s)
- Carri J LeRoy
- Department of Biological Sciences, Northern Arizona University, Flagstaff 86011, USA.
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Swanson BO, Gibb AC, Marks JC, Hendrickson DA. TROPHIC POLYMORPHISM AND BEHAVIORAL DIFFERENCES DECREASE INTRASPECIFIC COMPETITION IN A CICHLID, HERICHTHYS MINCKLEYI. Ecology 2003. [DOI: 10.1890/02-0353] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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O'Brien DF, Caird J, Kennedy M, Roberts GA, Marks JC, Allcutt DA. Posterior fossa tumours in childhood: evaluation of presenting clinical features. Ir Med J 2001; 94:52-3. [PMID: 11321174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
A retrospective review was performed of the age profile and clinical features at presentation of 79 children with posterior fossa tumours. The mean age at presentation in this series (6.6 years) is consistent with a decreasing trend over the past 70 years. Headaches, ataxia and torticollis emerge as significant symptoms worthy of further investigation whilst abdominal pain and constipation might herald the presence of a posterior fossa tumour on rare occasions.
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Affiliation(s)
- D F O'Brien
- Department of Neurosurgery, Beaumont Hospital, Dublin, Republic of Ireland
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Kupferberg SJ, Marks JC, Power ME. Effects of Variation in Natural Algal and Detrital Diets on Larval Anuran (Hyla regilla) Life-History Traits. COPEIA 1994. [DOI: 10.2307/1446992] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Losos JB, Marks JC, Schoener TW. Habitat use and ecological interactions of an introduced and a native species of Anolis lizard on Grand Cayman, with a review of the outcomes of anole introductions. Oecologia 1993; 95:525-532. [DOI: 10.1007/bf00317437] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/1993] [Accepted: 04/21/1993] [Indexed: 10/24/2022]
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Marks JC. Daily index offers snapshot of financial health. Healthc Financ Manage 1990; 44:80, 82. [PMID: 10145238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Abstract
Metastatic carcinoma of the prostate is a common cause of spinal cord compression. In this review of 37 men who underwent laminectomy for this condition this was the first presentation of previously undiagnosed cancer in 11 (29%). One year after decompression 17 (50%) were alive. Twenty patients (59%) could walk after laminectomy. All but 8 were relieved of pain and bladder function was improved in 13 (38%). Those ambulant before laminectomy (7) and those with occult prostate cancer did particularly well. Poor results were associated with a rapid onset of paraparesis and pre-operative progression to paraplegia. A delay in diagnosis was detrimental to outcome. A high index of suspicion in patients with carcinoma of the prostate is essential so that early diagnosis can be made before paraplegia is established. Carcinoma of the prostate must always be excluded in men with cord compression of unknown aetiology.
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