Fig. 1. A 14 bp regulatory element in the Xanf1 promoter restricts of Xanf1 expression to the presumptive forebrain. (A) Brain of a transgenic embryo bearing the double-reporter vector shown at the top demonstrates similar expression patterns of EGFP (green) and RFP (red) driven by promoter fragments -203 to +1 and -2200 to +1 respectively. (B) Deletion of a 14 bp promoter element (yellow), from the EGFP reporter cassette (top) results in the posterior shift in the EGFP reporter expression in the CNS of another transgenic embryo bearing this vector (bottom). RFP expression driven by the complete promoter fragment, -2200 to +1, is still localised in the forebrain (middle).