Transcriptomic analysis of shrimp immune modulation by dietary inactivated microbial cells and Sargassum sp. immunostimulants

Research on the shrimp immune system has piqued attention in recent years, as a better understanding of the events that occur in the shrimp immune system could assist to improve shrimp's overall health and, as a result, increase shrimp production output. This study focuses on Litopenaeus vannamei, employing transcriptomic analysis to understand gene expression and immune responses. Shrimp were immunostimulated using feed-based inactivated microbial cells with Sargassum sp.. Shrimp treated with immunostimulants exhibited no physical changes after immunisation, and histological investigation of the hepatopancreas indicated normal cell architectures across groups given 1 × 10 5 CFU kg/feed + Commercial feed with 2% Sargassum sp. via oral route. RNA sequencing and quality assessment were performed, resulting in 84,545 transcripts and 47,763 unigenes. Functional annotation using multiple databases (NR, NT, KO, SwissProt, PFAM, GO, KOG) revealed that 63.36% of unigenes could be annotated, with significant matches to known immune-related genes. Differential expression analysis identified 2,868 up-regulated and 4,721 down-regulated genes between the treated and control groups. Key immune-related genes, including those involved in pathogen response, antimicrobial peptide production, and various immune signaling pathways (e.g., Toll, JAK-STAT, P13K-AKT, Wnt), showed significant differential expression. This study provides valuable insights into the molecular basis of shrimp immune responses, highlighting the potential of functional genomics to enhance shrimp health and production through targeted immunostimulants.