EFFICIENT INDUCTION OF POINT MUTATIONS ALLOWING RECOVERY OF SPECIFIC-LOCUS MUTATIONS IN ZEBRAFISH

A technique is described that greatly increases the efficiency of reco vering specific locus point mutations in zebrafish (Danio rerio). Foun der individuals that were mosaic for point mutations were produced by mutagenizing postmeiotic gametes with the alkylating agent N-ethyl-N-n itrosourea. Under optimal conditions, each founder carried an average of 10 mutations affecting genes required for embryogenesis. Moreover, approximate to 2% of these founders transmitted new mutations at any p respecified pigmentation locus. Analyses of new pigmentation mutations confirmed that most were likely to be point mutations. Thus, mutagene sis of postmeiotic gametes with N-ethyl-N-nitrosourea yielded frequenc ies of point mutations at specific loci that were 10- to 15-fold highe r than previously achieved in zebrafish. Our procedure should, therefo re, greatly facilitate recovery of multiple mutant alleles at any locu s of interest.