sentences:  Coltiviruses replicate in the cytoplasm in cells of both arthropods and vertebrates, but they are only transmitted by the arthropods.When the virus replicates, the virion outer shell has to be removed in order for RNA polymerase to be activated to continue the replication of the virion's RNA.Reassortment of the RNA segments in progeny is common, and this plays a role in some of the genetic diversity between the serotypes.