Genetic variation of the nucleocapsid genes of waterfowl parvovirus

Duck parvovirus (DPV) and Goose parvovirus (GPV) isolated from infected wat erfowls with Derzsy's disease in the year 1999 were identified by polymeras e chain reaction and sequencing. The nucleotide sequences of their viral ca psid proteins (VPS) show that they share 77% similarity at the DNA, and 84. 6% at the protein level. The most variable region between DPV and GPV resid es in the N-terminal of VP2 before the initiation codon of VP3 with 35% (19 /54) amino acids divergence. Viral capsid protein sequences diverge 4.1 to 4.4% among 1990-99 isolated strains. Variant amino acids cluster in the com mon regions of VP3 at residues 203-266 and 482-534 which overlaps with the regions proposed to expose on the outer surfaces of parvoviral particles, i mplying that selective pressure from host immune system might play a part. These data provide useful information for antigenic epitope prediction. Thi s study also reveal the presence of conserved strain-specific residues in V Ps and these residues seldom vary among different viral isolates, suggestin g that they might be functionally important and worth further investigation .