Nuclear involvement poin xvirus infection.

During the first hours of infection with vaccinia virus, part of the chromosomal DNA of host cells is degraded, part of it is released from the cell, and part of it eventually appears in cytoplasmic foci associated with the reproduction of virus. The DNA of the infecting particle is first found attached to the chromosomes. Intranuclear foci of DNA incorporation appear later; these rapidly move out into the perinuclear space and eventually become typical cytoplasmic "virus factories." Each of these observations points to a more direct involvement of the nucleus in viral infection than was previously envisaged.