Investigations about the Formation of Incomplete Forms of Fowl Plague Virus.

During the formation of incomplete fowl plague virus, normal amounts of viral compounds are synthesized. The S-antigen, however, cannot be demonstrated within the cytoplasm in appreciable amounts by fluorescent antibody. The oligonucleotide pattern and the specific radioactivity of the ribonucleic acid (RNA) of incomplete forms are almost identical with those of standard virus. In contrast to chemically inactivated viruses no indication of multiplicity reactivation was found with incomplete forms. It is suggested that the incomplete forms are lacking in identical pieces of their genome, but contain that part of their RNA which codes for ‘early protein ’, S-antigen and haemagglutinin.