Ultrastructural Studies of Cell-Virus Interaction in Reptilian Cell Lines. I. Intramitochondrial Viruses in “C-Type” Virus-Producing VSW Cells

Abstract

Intramitochondrial virus particles were observed by thin-section electron microscopy in a permanent cell line, VSW, derived fromthe spleen of a tumor-bearing Asian pit viper. Viruses were spherical in morphology and generally situated in the peripheral region of the mitochondrion. They measured approximately 106 mµ in total diameter and consisted of a relatively dense nucleoid surrounded by a less-dense outer zone. The latter consisted of at least one intermediary layer enclosed by a tight-fitting envelope derived from the inner mitochondrial membrane. Probable developmental stages are described, and speculation concerning their possible evolutionary significance is presented.