Figure 3.

Gene trapping using the Gal4FF-UAS system. (A) Scheme for the Gal4FF gene trapping. A plasmid DNA containing a Gal4FF construct and the transposase mRNA were co-injected into fertilized eggs. The injected fish were raised and mated with the reporter fish homozygous for the UAS:GFP insertion. The resulting F1 embryos were analyzed with a fluorescence stereomicroscope. F1 embryos expressing GFP were collected and raised for further studies. (B) Examples of GFP expression in the spinal cord and the motor nerve in F1 embryos at 48 hpf. In the left, the primary motoneurons are exclusively labeled. In the right, a large number of GFP labeled cells are observed in the ventral spinal cord. The dotted line demarcates the ventral limit of the spinal cord. The rostral is to the left. The bar indicates 50 μm.