Biotechnology and Bioinformatics (1+1)

2.2.3.3. Disease resistance

Fish has poorly developed antibody dependent immunity. Efforts to produce disease resistance in fish stocks by transgenesis have begun recently. The potential of Rainbow trout lysozyme gene as a bacterial inhibitor was assessed in Atlantic salmon.

· Lysozyme is a nonspecific antibacterial enzyme present in the blood, mucus, kidney, and lymphomyeloid tissues in fish (Hew et al., 1995). Rainbow trout contain elevated levels of lysozyme (10- to 20-fold higher than in Atlantic salmon) and a rainbow trout lysozyme cDNA construct with an ocean pout AFP promoter has been created.

· Rainbow trout were recently reported to have 2 distinct types of lysozymes, with only type II having significant bactericidal activity (Mitra et al., 2003). The gene for type II lysozyme was amplified and sequence d for future use in transgenic immune system enhancement of farmed fish.

· The potential of Rainbow trout lysozyme gene as a bacterial inhibitor was assessed in Atlantic salmon. There is enormous promise in the application of transgenesis for enhancing fish health.