Figure 2. The Fra ICD is sufficient to fully rescue comm expression and partially rescue midline crossing defects in commissural neurons of fra mutants.

A) Fluorescent in situ hybridization for comm mRNA (green) in stage 14 embryos. Anterior is up. The cell bodies and axons of EW neurons are labeled with eg-Gal4 driving expression of UAS-Tau-Myc-GFP. Anti-Myc immunostaining is shown in magenta. White circles indicate the positions of EW neuron cell bodies. Solid circles indicate EW neurons that express comm and dotted circles indicate EW neurons that do not express comm. Open arrowheads indicate segments in which EW axons fail to cross the midline.

B) Quantification of EW axon crossing in stage 14 embryos. Data were analyzed by ANOVA, followed by Student's t-test. *** indicates p<0.0001, compared to fra³ mutants. ** indicates p=0.0002, compared to fra³ mutants. Error bars indicate SEM. Number in parentheses indicates number of embryos scored. Note that the data for fra³ heterozygotes and mutants are also shown in Figures 6A and S3.

C) Quantification of comm expression in EW neurons in stage 14 embryos. Data were analyzed by ANOVA, followed by Student's t-test. *** indicates p<0.0001, compared to fra³ mutants. * indicates p<0.01, compared to fra mutants. Error bars indicate SEM. Number in parentheses indicates number of embryos scored. Note that the data for fra³ heterozygotes and mutants are also shown in Figures 6B and S2.