The GAL4 enhancer-trap line for analysis of definitive hematopoiesis in zebrafish

Zebrafish have been used as model vertebrates in several genetic studies. In developmental biology, gene function can be assessed through manipulation of the spatial expression or the temporal misexpression of target genes. In this study, we performed a developmental screen to identify a regulated enhancer of hematopoiesis capable of driving tissue-specific Gal4 expression in zebrafish. This Gal4/upstream activating sequence (UAS) system could be used to investigate regulatory interactions during embryonic development. We obtained a Tg[RBC:Gal4] transgenic line that showed red fluorescence protein (rfp) reporter gene expression during early embryonic hematopoiesis. Further analysis indicated the production of RFP-positive erythrocytes in a Tg[RBC:Gal4] transgenic line. By controlling the amount of metronidazole, which was used to induce production of an apoptosis-inducing reagent, we successfully created a conditional model of anemia using Tg[RBC:Gal4], Tg[UAS:RFP], and Tg[UAS:nfsB-mCherry] triple transge...