학술논문
Altered growth and death in dilution-based viral predation assays.
Document Type
Academic Journal
Author
Knowles B; Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America.; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, California, United States of America.; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California, United States of America.; Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, Los Angeles, California, United States of America.; Institute of the Environment and Sustainability, University of California, Los Angeles, Los Angeles, California, United States of America.; Bonachela JA; Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, New Jersey, United States of America.; Cieslik N; Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America.; Della Penna A; School of Biological Sciences, University of Auckland, Auckland, New Zealand.; Institute of Marine Science, University of Auckland, Auckland, New Zealand.; Diaz B; Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America.; Baetge N; Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, California, United States of America.; Behrenfeld MJ; Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America.; Naumovitz K; Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America.; Boss E; School of Marine Sciences, University of Maine, Orono, Maine, United States of America.; Graff JR; Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America.; Halsey KH; Department of Microbiology, Oregon State University, Corvallis, Oregon, United States of America.; Haramaty L; Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America.; Karp-Boss L; School of Marine Sciences, University of Maine, Orono, Maine, United States of America.; Bidle KD; Department of Marine and Coastal Science, Rutgers University, New Brunswick, New Jersey, United States of America.
Source
Publisher: Public Library of Science Country of Publication: United States NLM ID: 101285081 Publication Model: eCollection Cited Medium: Internet ISSN: 1932-6203 (Electronic) Linking ISSN: 19326203 NLM ISO Abbreviation: PLoS One Subsets: MEDLINE
Subject
Language
English
Abstract
Viral lysis of phytoplankton is one of the most common forms of death on Earth. Building on an assay used extensively to assess rates of phytoplankton loss to predation by grazers, lysis rates are increasingly quantified through dilution-based techniques. In this approach, dilution of viruses and hosts are expected to reduce infection rates and thus increase host net growth rates (i.e., accumulation rates). The difference between diluted and undiluted host growth rates is interpreted as a measurable proxy for the rate of viral lytic death. These assays are usually conducted in volumes ≥ 1 L. To increase throughput, we implemented a miniaturized, high-throughput, high-replication, flow cytometric microplate dilution assay to measure viral lysis in environmental samples sourced from a suburban pond and the North Atlantic Ocean. The most notable outcome we observed was a decline in phytoplankton densities that was exacerbated by dilution, instead of the increased growth rates expected from lowered virus-phytoplankton encounters. We sought to explain this counterintuitive outcome using theoretical, environmental, and experimental analyses. Our study shows that, while die-offs could be partly explained by a 'plate effect' due to small incubation volumes and cells adhering to walls, the declines in phytoplankton densities are not volume-dependent. Rather, they are driven by many density- and physiology-dependent effects of dilution on predation pressure, nutrient limitation, and growth, all of which violate the original assumptions of dilution assays. As these effects are volume-independent, these processes likely occur in all dilution assays that our analyses show to be remarkably sensitive to dilution-altered phytoplankton growth and insensitive to actual predation pressure. Incorporating altered growth as well as predation, we present a logical framework that categorizes locations by the relative dominance of these mechanisms, with general applicability to dilution-based assays.
Competing Interests: The authors have declared that no competing interests exist.
(Copyright: © 2023 Knowles et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
Competing Interests: The authors have declared that no competing interests exist.
(Copyright: © 2023 Knowles et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)