Figure 7. Conceptual model depicting viral strategies for exploiting the marine microbiome.

In the warm waters of the photic zone, Cyanophages would be enriched and display a preference for lysogenic infections. Under these same conditions, Pelagiphages and viruses infecting heterotrophic bacteria would be depleted and prefer lytic infections. In the cold waters of the photic zone, the opposite pattern would occur: Cyanophages depleted and lytic, and Pelagiphages and viruses infecting heterotrophic bacteria would be enriched and lysogenic infections. In the cold waters of the aphotic zone, both Cyanophages and Pelagiphages would be depleted and lytic, while viruses infecting heterotrophic bacteria would be enriched and lysogenic. Throughout these gradients, these viruses carry different types of auxiliary metabolic genes that help them to exploit host metabolism during infection.