Cytomegalovirus infection in the submandibular and parotid salivary glands of an African grass mouse (Arvicanthus dembeensis).

The submandibular and parotid glands of one of five specimens of African grass mice (Arvicanthus dembeensis) were found to be infected with cytomegaloviruses, producing a profound cytomegaly in certain cells at the juncture of secretory endpieces and intercalated ducts. These cytomegalic cells tended to have multiple nuclei, many of which contained a characteristic reticular inclusion. The viruses appeared to arise in association with the intranuclear inclusions, then passed through the nuclear envelope to the cytoplasm where they budded into Golgi saccules or into small vacuoles, presumably of Golgi origin. Fusion of small virus-carrying vacuoles led to the formation of large vacuoles containing a plethora of viruses. Viruses were liberated into gland lumina via fusion of the vacuoles with the luminal plasmalemma. Fusion of vacuoles with dehiscent ones resulted in a form of chain exocytosis. The development of cytomegaloviruses in salivary glands may differ in details in a species-specific manner.