Sequencing and Analysis Genome of a VIb Subgenotype of Newcastle Disease Virus Isolated from Semi-Muscovy Duck

Based on the genome sequence of newcastle disease virus(NDV) published in GenBank，nine pairs of gene-specific primers were designed to amplify cDNA of FJ-SMD-03 strain isolated from Semi-Muscovy duck in Fuzhou, Fujian ,then sequecing and analysis were performed. The results showed that FJ-SMD-03 was 15 192 nucleotides in length which consisted of six ORFs in the order of 3′leader-NP-P-M-F-HN-L-5′trailer and it had six nucleotides longer than Lasota strain in non-coding region of NP gene. The genome shared the highest similarity of the nucleotide with 1.3,carrier-pigeon/Guangdong/2008,pigeon/Italy/1166/00,AV324/96 and dove/Italy/2736/00 (94.9%-98.5%),and shared the lowest similarity of the nucleotide with vaccine strain Lasota,Mukteswar and B1(80.7%-83.3%), whereas it shared lower similarity of the nucleotide with strain F₄₈E₈ and Muscovy duck/China(Fujian)/FP1/02,Subgenotype VIId, velogenic, isolated from Muscovy duck in Fujian during 2002 for 82.5% and 87.1% respectively. The motif of cleavage site region of F gene was ¹¹²R-R-Q-K-R-F¹¹⁷, which was the sequence signature of virulent strain. Phylogenetic analysis revealed that FJ-SMD-03 belonged to subgenotype VIb, Class Ⅱ, which was the first report of the subgenotype VIb virulent NDV strain isolated from Semi-Muscovy duck. FJ-SMD-03 was closely associated with 1.3,carrier-pigeon/Guangdong/2008 and pigeon/Italy/1166/00 and formed a secondary branch in the phylogenetic tree with carrier-pigeon/Guangdong/2008, which suggested that FJ-SMD-03, carrier-pigeon/Guangdong/2008 and pigeon/Italy/1166/00 came from the same origin, which might be due to virus carried by pigeons.