The mstn, mc4r and lh loci were knocked out for channel catfish, Ictalurus punctatus and replaced with alligator cathelicidin, cecropin, masu salmon Δ5-desaturase like gene (D5D), masu salmon elongase (elovl2), fat1 and fat2 from C. elegans transgenes in various combinations. This resulted in fish that had as much as a 4X increase in bacterial disease resistance, increased viral resistance, a 50% increase in growth rate, upwards to a doubling of various omega-3 fatty acids and an inability to spawn. The omega-3:omega-6 fatty acid ratio was increased. Fertility was restored by using luteinizing hormone releasing hormone analogue (LHRHa) or LHRHa with human chorionic gonadotropin depending upon the genotype of the fish.
Fatty acid biosynthesis transgenic channel catfish demonstrated pleiotropic increases in growth and disease resistance for some genotypes. Other such genotypes had poor disease resistance that could be corrected by mating with cathelicidin and cecropin transgenic lines.
There were significant effects due to insertion site. Insertion of two copies of an antimicrobial protein (AMP) transgene or two different AMP transgenes increase bacterial disease resistance more than a single AMP insert. Off-target effects occurred in one case causing a high frequency of deformed individuals. Suites of traits can be improved with this approach. Future research should address combining this integrated approach with traditional genetic enhancement programs.