**4. Generation of recombinant VZV using a highly efficient homologous recombinant system**

To test the novel VZVLuc system for studying VZV pathogenesis, five single ORF deletion mutants were first generated, starting from ORF0 to ORF5, via the homologous recombination system harbored in DY380 *E. coli*. Afterwards, the VZVLuc was used for genome-wide mutagenesis to systematically delete each individual VZV ORF for functional characterization of the VZV genome.
