At least two retroviruses, endogenous feline leukemia virus (FeLV) and RD-114 virus, are assumed to be integrated in the genome of domestic cats (1). Several feline cell lines have been shown to produce RD-114-related viruses (2). In Japan, feline cell lines are widely used to produce vaccines for dogs, particularly against canine parvovirus. The level of infectious RD-114 virus found in canine...

GENERAL PROPERTIES OF RNA COLIPHAGES ...... ..................... 110 Structure ofPhage Particles ................................................. 110 Infection and Phage Development .......................................... 110 PHAGE GENES AND THEIR PRODUCTS ........ .......................... 112 Identification ofPhage Genes .............................................. 112 Gene Order .......

.............................................................................................................. 113 Introduction .......................................................................................................... 113 Study area, material and methods ........................................................................... 114 Results ........................................