F gene recombination between genotype II and VII Newcastle disease virus.

A velogenic Newcastle disease virus (NDV) strain, designated as SRZ03, was isolated from an egg layer flock with NDV vaccine immunization failure in China in 2003. Recombination was found in the F gene of SRZ03. Complete genome sequences analysis indicated that the N-terminal of SRZ03 F gene originated from a genotype II NDV strain, whereas the C-terminal of F gene and the rest of the genes originated from a prevalent velogenic genotype VII NDV strain. It provides us valuable information for understanding the recombination of nonsegmented negative-sense RNA viruses.