Some pigeon paramyxovirus type 1 (PPMV-1) strains exhibit low virulence in chickens, despite their fusion (F) protein's multi-basic cleavage site. To elucidate the molecular basis of the low pathogenicity of these strains, we constructed an infectious full-length cDNA clone of PPMV-1 strain AV324. This strain is non-virulent for chickens, although its F protein contains the typical virulence motif (RRKKRF117)-R-112. By using reverse genetics, we exchanged the F genes of AV324 and a virulent Newcastle disease virus (NDV) strain (Herts) and evaluated the recovered chimeric viruses for their pathogenicity in 1-day-old chickens and in embryonated eggs. Our results show that the F protein of AV324, and probably those of similar PPMV-1 strains, are functionally not different from those of virulent NDV strains and that the difference in pathogenicity must be determined by other factors.
- newcastle-disease virus
- complete nucleotide-sequence
Dortmans, J. C. F. M., Koch, G., Rottier, P. J. M., & Peeters, B. P. H. (2009). Virulence of pigeon paramyxovirus type 1 does not always correlate with the cleavability of its fusion protein. Journal of General Virology, 90(11), 2746-2750. https://doi.org/10.1099/vir.0.014118-0