Host-Virus Interaction: From Metagenomics to Single-Cell Genomics

Abstract

It is widely appreciated today that viruses are a dominant and critical part of Earth's biosphere. Yet despite the major advances in the study of environmental viruses in most cases, our knowledge of which viruses go with which hosts is meager. In the classic phage isolation technique, known as the plaque assay, a confluent layer of host cells is infected with a low density of viral particles. When a virus infects a cell within this "lawn" of host cells, the cell lyses, and new viral particles infect adjacent cells thereby creating a clearing, or plaque, in the lawn. This technique for isolating viruses requires that the host of the virus be culturable. However, given that >99% of microbes on Earth cannot be cultured at this time, the vast majority of phage-host systems cannot be investigated in the laboratory using these classical phage enrichment techniques. Consequently, little is known about the biology of most viruses and their host specificity in the wild.

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