Enhancer Trapping and Annotation in Zebrafish Mediated with Sleeping Beauty, piggyBac and Tol2 Transposons.

Although transposon-mediated enhancer trapping (ET) is successfully applied in diverse models, the efficiency of various transposon systems varies significantly, and little information is available regarding efficiency of enhancer trapping by various transposons in zebrafish. Most potential enhancers (Ens) still lack evidence of actual En activity. Here, we compared the differences in ET efficiency between (), () and transposons. represented the highest germline transfer efficiencies at 55.56% (N = 165), followed by (38.36%, N = 151) and (32.65%, N = 149). ET lines generated by the transposon tended to produce offspring with a single expression pattern per line, while and tended to generate embryos with multiple expression patterns. In our tests, 10 putative Ens (En1⁻10) were identified by splinkerette PCR and comparative genomic analysis. Combining the expression profiles and mRNA expression patterns revealed that En1 and En2 may be involved in regulation of the expression of and , while En6 may be involved in regulation of the expression of line TK4 transgene and , and En7 may be involved in the regulation of the expression of and . Most identified Ens were found to be transcribed in zebrafish embryos, and their regulatory function may involve eRNAs.