[Full-length genome analysis of four genotype 3 letogenic Newcastle disease viruses isolated from different hosts]

The purpose of this study is trying to analysis the homology between four lentogenic Class I genotype 3 Newcastle disease virus isolates from different hosts with NDV strain NDV 08-004, which was the first obtained complete genome sequence virus of class I genotype 3. The full-length genome of NDV isolates, JS/3/09/Ch, ZJ/3/10/Ch, AH/2/10/Du and JS/9/08/Go,were determined by RT-PCR and then an alyzed. All the genomes are 15 198 nucleotides (nt) in length. Compared with the full genome sequences of Class II NDV stains (genotype IV-IX),four isolates has a 6-nt deletion in the non-coding region of nuclear phosphoprotein gene between nucleotides 1 640-1 641 and 12-nt insertion in the coding region of phospho protein gene between nucleotides 2 381-2 382. All the isolates have the motifs 112EQ/RQE/GRL117 at the cleavage site of the fusion protein, which is typical of lenogenic NDV strains, and it is in agreement with the result of pathogenic tests. The full-length genome of 4 genotype 3 NDV isolates shared 93% nucleotide identity with NDV08-004. The results of alignment of 6 viral genes showed that NP gene shared the highest identity (98.3%-96.4%) and P gene shared the lowest identity (96.1%-91.9%). The results show the following two points. First, it is concluded that the isolates from different hosts share the same genotype has the insignificant divergence in the genetic information. Second, it is proposed that the mutation rates of NP/F/L genes are lower than P/M/HN genes.