Transcriptome profiling and differential expression analysis of the immune-related genes during the acute phase of infection with Photobacterium damselae subsp. damselae in silver pomfret (Pampus argenteus)

Silver pomfret has been widely cultured in China due to its high economic value. Photobacterium damselae subsp. damselae (PDD) is a Gram-negative bacterium that has been shown to infect many fish species. To increase knowledge of the molecular mechanisms of the host defense against PDD, we conducted transcriptome analysis of head kidney in silver pomfret at 24 h and 72 h post-infection (hpi) via Illumina sequencing. The de novo assembly resulted in the identification of 79,063 unigenes, with 59,386 (75.11%) successfully annotated in public databases (NR, NT, KO, Swiss-Prot, Pfam, GO, and KOG databases). Comparison of gene expression profiles between PBS-injected fish (sham control) and PDD-challenged fish revealed 329 and 570 differentially expressed genes (DEGs) were screened at 24 hpi and 72 hpi, respectively. The DEGs were enriched in multiple immune-related pathways such as Hepatitis C, Gastric acid secretion, CAMs and Leukocyte transendothelial migration pathways, Primary immunodeficieny, ECM-receptor interaction, PI3K-Akt signaling pathway. The data obtained in the present study offers valuable information for acute immune response of silver pomfret challenged with PDD, which will facilitate further investigations on strategies against Photobacterium spp. infection in teleosts.