Abstract: Objective To determine the effect of NS3 and NS4A proteins of Zika virus on the neuronal migration in vivo. Methods To identify the coding sequence of NS3 and NS4A, the genome of Zika SZ01 was sequenced by rapid amplification of cDNA ends (RACE) and reverse-transcription PCR, then NS3 and NS4A was constructed in pCIG vector fused with Flag-tag to express these proteins. And then these plasmids was transfected into the embryo brain of E13.5 mice by in utero electroporation, the distribution of the cells which express these proteins in the cortex was detected by Flag, GFP and TBR1 fluorescence in E18.5 mice through immunohistochemistry so as to assess the influence of viral proteins on the neuronal migration of mouse cortex. Results 1) Sequence results showed that the amino acid sequence of NS4A is consistent with NCBI data, while NS3 has an amino acid mutant. 2) As the fluorescence of Flag and eGFP can co-localization, the eGFP fluorescence signal can indicate the cells that have expressed these virus proteins in cortex. 3) TBR1 fluorescence shows the distribution of the cells that express NS4A in vivo are significantly different from pCIG control and NS3 (p<0.001). Conclusions The NS4A protein of Zika virus may affect the neuronal migration in vivo.

Key words: Zika virus, NS4A, in utero electroporation, neuronal migration