Molecular Characterization and Expression Analysis of the Zinc Finger Protein 703 (ZNF703) Gene from Starry Flounder, Platichthys stellatus

Zinc finger protein (ZNF) is widely expressed in eukaryotes and is involved in a number of important biological processes such as cell differentiation, proliferation and apoptosis. ZNF703 is one of the transcription factors that regulates the expression of multiple genes involved in transcription modulation, cell proliferation, cell cycle regulation, and signaling pathway regulation. However, studies on the immune response of ZNF703 after pathogen infection in fish are lacking. We analysed the coding sequence (CDS), genomic structure, and temporal variations in the mRNA transcription of ZNF703 after challenge with viral hemorrhagic septicemia virus (VHSV) and Streptococcus parauberis PH0710 in starry flounder (Platichthys stellatus) (Ps). PsZNF703 was confirmed to have a NLZ1 domain and ZNF C2H2 domain. The strongest expression of PsZNF703 mRNA in healthy starry flounder was observed in the gills. The expression pattern of PsZNF703 mRNA after infection with pathogens was significantly up-regulated in the spleen, liver, and intestine 12 h post-VHSV injection (***p 0.001). After infection with S. parauberis PH0710, the PsZNF703 mRNA expression pattern was up-regulated in almost all major tissues, whereas it was significantly down-regulated in the gills and heart. Our results indicate that PsZNF703 may be involved in the host immune response to starry flounders.