Fig. 1

a Genomic structure of the Zika virus. b Schematic diagram showing the structure of pBAC-ZIKA. CMV, HDV, and BGH denote the CMV promoter sequences, the hepatitis delta virus ribozyme sequence, and the bovine growth hormone terminator sequence, respectively. SfoI and PacI are restriction endonucleases. pBAC-ZIKA was constructed by recombination of the ZF and ZR fragments using the restriction-digested vector. c Schematic diagram showing the structure of pBAC-ZIKAi. The ZFi fragment was generated by inserting the intron sequence into the genomic sequence of the Zika virus downstream of 3128 nt, followed by its recombination with ZR with the restriction-digested vector to generate pBAC-ZIKAi. d pBAC–ZIKA–EGFP was constructed by inserting the EGFP-2A gene downstream of the 37th codon of the Zika virus sequence