During
infection, feline calicivirus (FCV) produces an abundant
subgenomic RNA of 2.4 kb that is the major template for translation of the single
capsid protein. Feline cells infected with FCV (
CFI/68 strain) at a high multiplicity of
infection produced a population of lower density (ld) viral particles with a density of 1.35 g/cc as compared to the 1.39 g/cc density of the wild-type virus particle. The
RNA isolated from the ld particles was 2.4 kb in size, the same as that of the intracellular subgenomic transcript that encodes the single
capsid protein of the virus. Primer extension analysis revealed that the 5' end of the
RNA from the ld particles mapped to the same genomic location as the intracellular 2.4 kb
RNA.
RNA protection of the ld
RNA using a FCV 4.2 kb minus strand
cDNA containing 1984 bases of
capsid protein coding sequences, protected an
RNA fragment of approximately 2000 bases. The data presented here demonstrates that the ld particles contains the FCV
subgenomic RNA and not a genomic
RNA containing rearrangements or deletions.