High-MOI induces rapid CRISPR spacer acquisition in Sulfolobus from an acr deficient virus.

Spacer acquisition, the first step in CRISPR-Cas adaptive immunity, plays a critical role in establishing and strengthening host defense against mobile genetic elements (MGEs). Here we present a host-virus system, where an increase in the multiplicity of infection (MOI), of a CRISPR-Cas susceptible virus, forces rapid spacer acquisition in the Sulfolobus islandicusSulfolobus islandicus