Expression dynamics of antimicrobial peptides during developmental stages of Genetically Improved Farmed Tilapia (GIFT), Oreochromis niloticus.

Fish are aquatic vertebrates that are free-living from their embryonic stages and are constantly in contact with the highly diverse and pathogen-rich external aquatic environment. The innate immune system of fish is non-specific and adapted to detect potential pathogens and other stress factors. They can act rapidly and effectively via their key component, the antimicrobial peptides (AMPs). The action of AMP is manifested through the regulation of its expression, and profiling the constitutive expression of key AMPs across various developmental stages in fish provides valuable insights into the transcriptomic mechanisms underlying their defense strategies against infections. Real-time quantitative PCR (RT-qPCR) was employed to quantify the expression of AMPs across the growth stages of Genetically Improved Farmed Tilapia (GIFT), Oreochromis niloticus. The analysis revealed distinct expression patterns of AMPs throughout the developmental stages of GIFT, indicating their critical role in immune preparedness. The expression profiles were specific to the peptide and the growth stages, and enhanced expression was particularly evident during the first post-hatch and first-feeding stages; no specific pattern could be deciphered during the other stages. The dynamic transcriptome, revealed through gene expression studies, provides a window into the intricate interplay of developmental and regulatory pathways. Monitoring the AMP expression profile offers an in-depth understanding of their mechanisms, paving the way for downstream applications in aquaculture, such as early disease detection and prevention, environment management, use of immunostimulants and probiotics, and in functional genomic studies.