Molecular Identification and Expression Analysis of NOD1/2 and TBK1 in Response to Viral or Bacterial Infection in the Spotted Knifejaw ().

This study investigates the role of the , , and genes in antiviral and antibacterial immunity of spotted knifejaw (). The expression patterns of these genes were analyzed using qRT-PCR in different tissues and at different time points. The open reading frame (ORF) of the gene was 2757 bp in length and encoded 918 amino acids, the ORF of the gene was 2970 bp in length and encoded 990 amino acids, while the gene was 2172 bp in length and encoded 723 amino acids. The Opnod1 and Opnod2 proteins contained three conserved domains (CARD, NOD, and LRR), and Optbk1 contained an STKc domain. The , and genes were mainly expressed in immune-related tissues of spotted knifejaw, with the highest relative expression of the in the skin, the in the gill, and the in the liver. The expression of these genes changed significantly in the immune tissues following infection with SKIV-SD and . In kidney cells, the , , and expression was up-regulated after stimulation by poly I:C and LPS in vitro. The results suggest that the NOD1/2-TBK1 signal pathway may play an important role in the resistance of the spotted knifejaw to virus and bacteria, providing valuable insights for disease-resistant breeding.