Attainment of minimal biological variability and measurements of genotoxicity: production of homozygous diploid zebra fish.

Zebra fish (Brachydanio rerio) are particularly suited for carcinogenicity testing and for the establishment of quantitative dose-response relationships. They are small, prolific, have short generation times, and produce eggs which develop synchronously and can be treated at identical developmental stages. Clones of homozygotes with minimal genetic variability provide a reproducible biological test system. Rapid measurements of the frequency of induced somatic mosaicism (demonstrated with gamma radiation, ethyl methanesulfonate, and ethylnitrosourea) and induced germ-line recessive-lethal mutation provide indexes of exposure.