title: Oncornavirus-like particles in squirrel monkey (Saimiri sciureus) placenta and placenta culture.
abstract: Oncornavirus-like particles similar in morphology to type D particles were observed in 1 of 2 squirrel monkey (Saimiri sciureus) placentas. Intracytoplasmic type A particles, immature virus particles, and mature viruses with eccentric or occasionally centric nucleoids were associated with placental syncytiotrophoblasts. A spike layer typical of type B viruses was not detected in viral envelopes. Onvornaviruses, identical to those previously isolated from squirrel monkey tissues and similar to Mason-Pfizer monkey virus, were seen in cultures derived from the virus-positive squirrel monkey placenta cocultivated with a mink lung culture. The major morphologic difference between the in vivo and the in vitro squirrel monkey virus was in the nucleoid position of mature virus particles.
mesh_terms: D000818:Animals; D046508:Culture Techniques; D005260:Female; D000882:Haplorhini / Q000382:microbiology*; D007181:Inclusion Bodies, Viral; D009858:Oncogenic Viruses / Q000302:isolation & purification* / Q000648:ultrastructure; D010920:Placenta / Q000382:microbiology* / Q000648:ultrastructure; D011247:Pregnancy; D012453:Saimiri / Q000382:microbiology*