Quantitative Infection Dynamics of Cafeteria Roenbergensis Virus.

Bradford Taylor,Corina Brussaard,Matthias Fischer,Joshua Weitz

doi:10.3390/v10090468

Abstract

The discovery of giant viruses in unicellular eukaryotic hosts has raised new questions on the nature of viral life. Although many steps in the infection cycle of giant viruses have been identified, the quantitative life history traits associated with giant virus infection remain unknown or poorly constrained. In this study, we provide the first estimates of quantitative infection traits of a giant virus by tracking the infection dynamics of the bacterivorous protist Cafeteria roenbergensis and its lytic virus CroV. Leveraging mathematical models of infection, we quantitatively estimate the adsorption rate, onset of DNA replication, latency time, and burst size from time-series data. Additionally, by modulating the initial ratio of viruses to hosts, we also provide evidence of a potential MOI-dependence on adsorption and burst size. Our work provides a baseline characterization of giant virus infection dynamics relevant to ongoing efforts to understand the ecological role of giant viruses.

Highlights

Numerous eukaryotic viruses larger than 150 nm in diameter and 200 kbp in genome size that infect marine microbes have been identified in recent years [1,2,3,4]
By leveraging empirical data and mathematical models of infection, we estimated several life history traits related to infection by the giant DNA virus Cafeteria roenbergensis virus (CroV)
We propagated the uncertainty of measurements in our calculations in order to constrain life history trait estimates from regression techniques

Summary

Introduction

Numerous eukaryotic viruses larger than 150 nm in diameter and 200 kbp in genome size that infect marine microbes have been identified in recent years [1,2,3,4]. These “giant” viruses are hypothesized to have substantial ecological impacts on hosts including inducing population collapses [5] and controlling algal blooms [6,7]. Quantitative infection parameters that influence giant virus dynamics remain largely unknown. The giant Cafeteria roenbergensis virus (CroV) is a parasite of the bacterivorous protist.

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Results

Conclusion