Electron Microscopic Observations on T

Electron microscopic study of the H.R. strain of herpes simplex virus in cells of the chicken chorioallantoic membrane (1) suggested that the virus differentiates within the nucleus, where particles possessing a central core and a single limiting membrane are randomly dispersed. In this earlier work the finding that ruptured nuclei were associated with large numbers of intracytoplasmic particles possessing double membranes appeared to be consistent with the hypothesis that the virus acquired a second membrane in the cytoplasm after release from the nucleus. However, cells in tissue culture infected with the H F E M strain of herpes simplex virus and examined by Stoker, Smith, and Ross (2) and herpes B virus examined by Reissig and Melnick (3) subsequently revealed intranuclear particles with double as well as single membranes, thus raising the possibility that development could be completed in the nucleus. Recently, a strain (J.M.) of herpes simplex virus was found to crystallize (4) in a manner analogous to the adenoviruses (5-9). Moreover, the nuclear membranes of cells infected by this strain frequently showed remarkable proliferation. The purposes of this paper are to illustrate and describe the viral crystals as well as the morphology of the cellular response to infection, and to propose an hypothesis concerning the manner of development and the mechanisms whereby virus may gain egress from intact cells.