The concept of parasite-derived resistance-Deriving resistance genes from the parasite's own genome

A broadly-applicable strategy is proposed for genetically engineering resistance to parasites. The strategy involves deriving resistance genes from the genome of the parasite itself. Key gene products from the parasite, if present in a dysfunctional form, in excess, or at the wrong developmental stage, should disrupt the function of the parasite while having minimal affect on the host. Therefore, resistance might be routinely achieved by cloning the appropriate parasite gene, modifying its expression if necessary, and transforming it into the host genome. The QB bacteriophage is used to illustrate, specifically, how parasite-derived resistance might be engineered. Examples are given of pathogen-derived resistance as it already functions in nature, and potential applications of this strategy in agriculture are discussed. The advantages and limitations of parasite-derived resistance are outlined.