Microinjection of rat growth-hormone gene into zebrafish egg and production of transgenic zebrafish

Abstract

A plasmid containing rat growth-hormone gene was microinjected into fertilized zebrafish eggs prior to first cleavage; survival of the embryos one day after the injection averaged 46% Genomic DNA extracted from presumotive transgenic fish was analysed by slot-blot and Southern-blot hybridization using labelled plasmid as probe. Patterns of hybridization indicated genomic, extrachromosomal, as well as mosaic integration. The concentration of persisting extrachromosomal DNA progressively decreased in F₁ and F₂ generations. The growth rate of transgenic fish was higher in F₀ and F₁ generations, but lower in F₂, which may be due to translent expression of extrachromosomal DNA carrying the growth-hormone gene in F₀ and F₁ generations.