Host-derived viral transporter protein for nitrogen uptake in infected marine phytoplankton

, a host-derived ammonium transporter. This gene is transcribed during infection and when expressed in yeast mutants the viral protein is located to the plasma membrane and rescues growth when cultured with ammonium as the sole nitrogen source. We also show that viral infection alters the nature of nitrogen compound uptake of host cells, by both increasing substrate affinity and allowing the host to access diverse nitrogen sources. This is important because the availability of nitrogen often limits phytoplankton growth. Collectively, these data show that a virus can acquire genes encoding nutrient transporters from a host genome and that expression of the viral gene can alter the nutrient uptake behavior of host cells. These results have implications for understanding how viruses manipulate the physiology and ecology of phytoplankton, influence marine nutrient cycles, and act as vectors for horizontal gene transfer.