First report of Peroxiredoxin-5 (PRDX5) in starry flounder (Platichthys stellatus): Molecular features and expression...

In this study, the Peroxiredoxin-5 (PRDX5) gene from starry flounder (Platichthys stellatus, PsPRDX5) was identified through next-generation sequencing (NGS) and verified via cloning and sequencing. The predicted amino acid sequence, derived from the cDNA, was confirmed by multiple sequence alignment and phylogenetic analysis, establishing its homology with related sequences. PsPRDX5 mRNA was expressed across all examined tissues in healthy starry flounder, with distinct tissue-specific expression profiles. Following artificial infection with viral hemorrhagic septicemia virus (VHSV) and Streptococcus parauberis PH0710, significant alterations in PsPRDX5 mRNA expression were observed. VHSV infection resulted in a pronounced downregulation of PsPRDX5 in most major tissues, except for a significant upregulation in the intestine at 7 days post-infection. Conversely, infection with S. parauberis PH0710 led to a significant upregulation of PsPRDX5 in nearly all tissues. These results suggest that the differential expression of PsPRDX5 in response to VHSV and S. parauberis PH0710 reflects pathogen-specific immune and antioxidant defense mechanisms, highlighting the role of PsPRDX5 in the immune response of starry flounder to both viral and bacterial infections.