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Altered growth and death in dilution-based viral predation assays
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 ho...
Autores principales: | , , , , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10328242/ https://www.ncbi.nlm.nih.gov/pubmed/37418487 http://dx.doi.org/10.1371/journal.pone.0288114 |
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author | Knowles, Ben Bonachela, Juan A. Cieslik, Nick Della Penna, Alice Diaz, Ben Baetge, Nick Behrenfeld, Micheal J. Naumovitz, Karen Boss, Emmanuel Graff, Jason R. Halsey, Kimberly H. Haramaty, Liti Karp-Boss, Lee Bidle, Kay D. |
author_facet | Knowles, Ben Bonachela, Juan A. Cieslik, Nick Della Penna, Alice Diaz, Ben Baetge, Nick Behrenfeld, Micheal J. Naumovitz, Karen Boss, Emmanuel Graff, Jason R. Halsey, Kimberly H. Haramaty, Liti Karp-Boss, Lee Bidle, Kay D. |
author_sort | Knowles, Ben |
collection | PubMed |
description | 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. |
format | Online Article Text |
id | pubmed-10328242 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-103282422023-07-08 Altered growth and death in dilution-based viral predation assays Knowles, Ben Bonachela, Juan A. Cieslik, Nick Della Penna, Alice Diaz, Ben Baetge, Nick Behrenfeld, Micheal J. Naumovitz, Karen Boss, Emmanuel Graff, Jason R. Halsey, Kimberly H. Haramaty, Liti Karp-Boss, Lee Bidle, Kay D. PLoS One Research Article 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. Public Library of Science 2023-07-07 /pmc/articles/PMC10328242/ /pubmed/37418487 http://dx.doi.org/10.1371/journal.pone.0288114 Text en © 2023 Knowles et al https://creativecommons.org/licenses/by/4.0/This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Knowles, Ben Bonachela, Juan A. Cieslik, Nick Della Penna, Alice Diaz, Ben Baetge, Nick Behrenfeld, Micheal J. Naumovitz, Karen Boss, Emmanuel Graff, Jason R. Halsey, Kimberly H. Haramaty, Liti Karp-Boss, Lee Bidle, Kay D. Altered growth and death in dilution-based viral predation assays |
title | Altered growth and death in dilution-based viral predation assays |
title_full | Altered growth and death in dilution-based viral predation assays |
title_fullStr | Altered growth and death in dilution-based viral predation assays |
title_full_unstemmed | Altered growth and death in dilution-based viral predation assays |
title_short | Altered growth and death in dilution-based viral predation assays |
title_sort | altered growth and death in dilution-based viral predation assays |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10328242/ https://www.ncbi.nlm.nih.gov/pubmed/37418487 http://dx.doi.org/10.1371/journal.pone.0288114 |
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