Transposon-mediated enhancer trapping in medaka

Abstract

We tested the Sleeping Beauty transposable element for its ability to efficiently insert transgenes into the genome of medaka ( Oryzias latipes), an important model system for vertebrate development. We show that the SB transposon efficiently mediates integration of a reporter gene into the fish germ line. In pilot experiments, we established 174 transgenic lines with a transgenesis efficiency of 32%. Transgenes are stably transmitted to, and expressed in, subsequent generations. Interestingly, the transgenic lines show novel expression patterns with temporal and spatial specificity at a rate of 12% (21/174), likely due to both, enhancing and silencing position effects. Furthermore, promoter-dependent GFP expression in injected fish embryos is tightly correlated with germ line transmission, facilitating easy selection of founder fish. Thus, the SB transposon/transposase system provides a highly efficient tool for transgenesis in general and for the generation of novel reporter gene expression patterns in particular.