Methyltransferase WTAP participates in shrimp defense against Vibrio parahaemolyticus infection

Although the immune function of the methyltransferase Wilm's tumor 1-associated protein (WTAP) has been well-studied in vertebrates, its role in the invertebrate immune system remains limited. In this study, we identified the WTAP gene in Penaeus vannamei and investigated its potential role in shrimp innate immunity. RT-qPCR analysis revealed that WTAP was broadly expressed in key immune tissues of the shrimp, including hemocytes, intestines, hepatopancreas, and gills. WTAP expression was upregulated in the hepatopancreas and gills during Vibrio parahaemolyticus infection. Although knockdown of WTAP did not significantly affect the survival rate of shrimp infected with V. parahaemolyticus, there was a non-significant trend toward decreased survival, along with markedly increased bacterial loads in gills and hepatopancreas. Knockdown of WTAP also led to a significant reduction in the expression levels of ALF1/3/5/6 and PEN2/3/4. Furthermore, WTAP expression was regulated by NF-κB Relish and repressed by the transcription factors STAT and Dorsal. Our results demonstrated that P. vannamei WTAP, regulated by NF-κB Relish, inhibited V. parahaemolyticus proliferation by modulating the expression of antimicrobial peptides (AMPs). These findings deepen our understanding of WTAP's role in crustacean innate immunity and provide a crucial foundation for future research on the relationship between m⁶A modification and immune regulation in invertebrates.