Targeted gene expression in the zebrafish prechordal plate

Targeted gene expression is a powerful tool for understanding gene function in vivo. In zebrafish, overexpression of gene products is typically accomplished ubiquitously, without temporal and spatial specificity. However, the yeast Gal4/UAS system can be used for targeted gene expression in zebrafish. Here we describe the generation and characterization of Tg [ gsc: Gal4‐VP16 ] transgenic zebrafish lines that harbor a construct encoding Gal4‐VP16 transcriptional activator under the control of a fragment of the goosecoid gene promoter. Tg [ gsc:Gal4‐VP16 ] embryos express Gal4‐VP16 RNA in presumptive prechordal plate mesendoderm during late blastula and throughout gastrulation. By crossing these fish to Tg [ UAS‐GFP ] transgenic fish, we show that the gsc:Gal4‐VP16 transgene is capable of driving strong expression of a target gene in the prechordal plate and its derivatives during gastrulation and segmentation. Thus, the use of Tg [ gsc:Gal4‐VP16 ] fish can help in understanding gene function in the prechordal plate, an embryonic structure that is crucial for normal neural patterning. genesis 44:584–588, 2006. Published 2006 Wiley‐Liss, Inc.