A novel strategy for creating sterile fish by gene editing: Phase 1 ?Edit Reporter Gene?

Engineered zinkfinger proteins (ZFPs) have recently been applied for targeted mutagenesis aiming at correcting mutations of oncogenes (Ref. 1). One of the partners (SK) is member/coordinator of an EU project aiming at exploring the potential of ZFPs in hu man gene therapy (Ref. 2). The coordinating partner (PA) is in charge of a FUGE-project "KO-ZFISH" which aims at making targeted mutations in zebrafish, including knockout of the gnrh gene function to achieve sterile fish, through selection of ES cells wh ich have undergone homologous recombination (Ref. 3). The applicants presented the concept of this application at a trilateral (Norway-USA-Canada) workshop held in Washington, D.C. in November 2005 (Ref. 4). Escaped fish from aquaculture represents a s ubstantial environmental/ecological problem. Cross breeding between bred cultured strains with wild type may have negative impact on wild type stocks, e.g. genetic diversity habitat competition etc. In addition sexual maturation may cause losses in produc tion. Current protocols for obtaining sterility in cultured fish includes polyploidy and GMO approaches are not not sufficiently protective or accepted by consumers. Thus prinicipally new approaches to develop sterile fish in aquaculture are needed. Anot her major challenge to serious breeders is to prevent "free riders" to take their advanced fertile seeds to build up competing broodstocks and thus remove substantial parts of their costly gained competitive edge. Sterile fish would seem to be the ultimat e tool to provide de facto breeder's right and brand protection to the serious and honest broodstock operators. The aim of this work is to develop a platform strategy that leads to biological containment through controlled sterility in cultured fish stoc k as a major milestone to prevent the risk of genetic pollution of wild type stocks stocks and to provide the ultimate tool for the protection of breeders' rights.