Figure 3

Transient expression assay in zebrafish. The synthetic transposase mRNA and a transposon donor plasmid containing a Tol2 construct with the tentative spinal cord specific enhancer/promoter (Figure 2) and the gene encoding green fluorescent protein (GFP) are co-injected into zebrafish fertilized eggs. The Tol2 construct is excised from the donor plasmid and integrated into the genome of somatic cells. The activity of the enhancer can be visualized in the injected embryo, because GFP is expressed predominantly in a region where the enhancer/promoter should activate transcription [22].