Harnessing antimicrobial peptide genes to expedite disease-resistant enhancement in aquaculture: Transgenesis and genome editing

Numerous studies have demonstrated that genome editing and transgenesis by integrating vector-engineered antimicrobial peptide genes (AMGs) is effective to modulate the fishs innate immune system. To generalize the knowledge of AMG application in aquaculture, here we recruited 540 data entries from a pool of empirical studies, which included 18 peer-reviewed publications and spanning 12 diseases. We systematically re-processed and re-analyzed these data by harnessing a cross-disease meta-analysis. On aggregate, AMG-genetic engineering aimed at enhancing disease resistance was shown to decrease the number of colony-forming units of bacteria, improve lysozyme activity, increase the post-infection survival rates, and alter the expression of AMGs and immune-related genes in aquatic animals. Furthermore, the AMG-pathogen combating activity was triggered within two hours after infection and lasted 48 hours, and the overexpression of AMGs was dominant in the spleen and skin, followed by the kidney and liver during this period. Typically, regardless of the type of AMGs, the synergistic expression of AMGs with IL, IK{beta}, TGF{beta}, C3b and TLR in AMG-integrated fish contributed to activating inflammatory/immune responses against pathogens. In addition, innovative CRISPR/Cas9-mediated systems enabling the site-directed knock-in of foreign genes at multiple loci were presented and prospected for disease-resistant enhancement in combination with other favorable fish-producing traits, including fast-growing, sterility, and enriched fatty acid. Altogether, our findings indicated that AMGs as transgenes have substantial potential to modulate the fishs innate immune system and accelerate disease-resistant enhancement combined with genetic engineering.