Autointerference in Infectious Hematopoietic Necrosis Virus of Salmonid Fish 1

Summary

When serial passage of infectious hematopoietic necrosis virus was carried out in cultures of a salmon cell line, using undiluted virus inoculum at each transfer, the resulting yield of infectious virus was very significantly lower than in parallel cultures prepared with dilute virus inoculum. Under these conditions of autointerference, the morphology of the progeny virions was altered. Three types were observed, with mean lengths of 188, 118, and 81 nm respectively. Roughly 80% fell into the two shorter categories. When a dilute virus inoculum was used, almost all progeny virions belonged to the class with a mean length of 188 nm.