The Asian seabass (Lates calcarifer) is a commercially valuable species in freshwater aquaculture, renowned for its rapid growth and high market demand. However, bacterial infections represent a significant challenge to its health and production. While bacterial diseases in Asian seabass are common, infection caused by has not been previously reported in this species. This study aimed to explore the host immune response of freshwater-farmed Asian seabass to P. putida infection at the transcriptomic level. Fish were experimentally challenged with a lethal dose of P. putida. A high-throughput RNA sequencing (RNA-Seq) on the Illumina MiSeq platform was employed to understand changes in the head kidney transcriptomics. Comparative analysis between the infected and control groups identified 944 differentially expressed genes (DEGs) (p<0.05), comprising 679 upregulated and 265 downregulated genes. Functional annotation of these DEGs revealed biological processes, including immune responses, cellular processes, and stress-related pathways. This study provides the first transcriptomic analysis of the immune response of freshwater farmed Asian seabass to P. putida, offering novel insights into the molecular mechanisms of host defense. The findings also suggest that specific immune-related genes could serve as potential biomarkers for early disease detection and can help in the development of targeted disease management strategies in aquaculture.
Keywords: Lates calcarifer, Pseudomonas putida, Transcriptomics, RNA-Seq, Head Kidney, Differentially expressed genes.