ABSTRACT
Over the last 10 years the zebrafish, Danio rerio, a small egg-laying teleost from the Ganges river system in India has become an accepted laboratory model especially for studies in developmental biology. Its suitability for large scale mutagenesis screens will allow the genetic analysis of vertebrate embryogenesis. Several fish species show characteristics that make them particularly suited for gene transfer like short generation time and the daily availability of large numbers of eggs. Egg production is induced by a specific photoperiod, so that under artificial light cycles embryos can be produced throughout year in laboratory. Small aquarium fish represent easy to handle yet powerful experimental systems to study gene function in vertebrates. Easy breeding in the laboratory, large brood size and the transparency of embryos allow a detailed study of developmental processes. Small genome size, possibility of ploidy manipulation and availability of genomic maps for zebrafish, medaka and swordtails are the basis for a genetic approach to analyse gene function.
