Fig. 1

Schematic representation of the construction of full-length cDNA clone of NDV ZM10 strain and rZM10 expressing the RFP gene. A The full-length cDNA plasmid of the NDV genome was assembled from three fragments by ligation-independent cloning method. All the three fragments share 15 nt homologous sequence and are shown by different colors: blue (Fragment 1), Red (Fragment 2) and Green (Fragment 3). The full-length clone is under the control of T7 promoter; the fragment Tr was followed by the hepatitis delta virus (HDV) ribozyme and the T7 terminator. B Cloning strategy to incorporate the RFP gene into the full length NDV clone of strain ZM10. The RFP cassette was amplified from pLS-RFP vector and sub-cloned into the NDV full-length genome between the P and M gene incorporating the NDV gene-start and gene-end signals as an independent transcription unit (ITU). Kozak. Kozak sequence, ORF: open reading frame