Plasmids driven minigenome rescue system for Newcastle disease virus V4 strain.

We establish a plasmid-driven minigenome system for Newcastle disease virus (NDV) V4 strain. Unlike the previously reported T7 polymerase based rescue system for Mononegavirales, the developed strategy does not necessitate the introduction of exogenous T7 polymerase by helper virus or stably expressing cell lines. This was achieved by transfection of plasmid pCAGGS-T7. The open reading frame (ORF) of enhanced green-fluorescent protein (EGFP) gene was inserted into constructed minigenome system pBRT7-mini and has been successfully expressed. Further packaging experiments indicate that 3' end leader and 5' end trailer regions are important for replication, transcription and packaging.