Electron microscopic study of the formation of African horse-sickness virus

Summary BHK 21/13 cells infected with African horse-sickness virus (strain 13/63, type 3) for varying periods of time have been studied with the electron microscope. Evidence is presented to show that the virus does not multiply in the nucleus, but that replication occurs in the cytoplasmic matrix. It is also indicated that the particle often leaves the host cell with an envelope derived from the cell membrane. The diameter of the particle is roughly estimated to be 70 m., excluding the envelope.