Morphology, organelles and susceptibility to viruses of cultured ferret cells.

Cells explanted from a normal 6-week-old ferret's brain have been subcultured over 100 times, have undergone over 400 population doublings, possess ferret-specific antigens and are referred to as Mpf cells. Low passage-level Mpf cells formed diffuse colonies with ill-defined borders which had a swirling 'finger-print' pattern whereas the colonies formed by high passage-level cells were more densely populated and had distinct borders. Mpf cells at their 100th passage level appeared as a loose monolayer with ill-defined cytoplasmic borders and contained microfilaments, ovoid nuclei, granular endoplasmic reticula with large dilated cisternae filled with an amorphous medium electron-dense product, abundant free ribosomes, irregular and hypertrophic Golgi bodies, mitochondria, and lipid inclusions associated with lipofuscin deposits. Chains of vesicles, 120-150 nm in diameter, some opening to the exterior, were aligned at the cytoplasmic border. The Mpf cells exhibited cytopathology and synthesized progeny virus when exposed to representatives of the Arboviruses, Arenoviruses, Paramyxoviruses, Poxviruses, Retroviruses and Rhabdoviruses.