Fig. 4

Mutation of TCF/Lef sites within the Bf-Gsx-Up1 and Bf-Gsx-Up1c constructs. a Relative positions of TCF/Lef sites within the Bf-Gsx-Up1, Bf-Gsx-Up1a, Bf-Gsx-Up1b and Bf-Gsx-Up1c regulatory regions. TCF/Lef sites lie either side of the Bf-Gsx-Up1a/Bf-Gsx-Up1b split. ‘+’ symbols denote the presence of LacZ expression in the corresponding construct, with ‘+’ denoting low LacZ expression and ‘++’ high LacZ expression, whereas ‘–‘ denotes the absence of LacZ expression. b Schematic showing the DNA sequence of TCF/Lef site1 and TCF/Lef site2 before and after mutagenesis. Pink sequence denotes the TCF/Lef site ‘core’ sequence before mutation, whereas light gray sequence denotes the TCF/Lef site ‘core’ sequence after mutation. c Comparison of CNS expression incidence in the Bf-Gsx-Up1 construct with TCF/Lef binding motif mutants. The numbers of embryos displaying either nerve cord only, sensory vesicle only, or the nerve cord with sensory vesicle LacZ expression patterns have been recorded both as a percentage of the total number of embryos that developed and as raw numbers of embryos expressing LacZ for each domain alongside the total number of embryos that developed. Pink boxes denote the positions of intact TCF/Lef sites, whereas white crossed boxes indicate the positions of mutated TCF/Lef sites. d Comparison of CNS expression incidence in the Bf-Gsx-Up1c minimal enhancer construct with TCF/Lef binding motif mutants, with annotation as for (c)