Fig. 2. NLS insertions restrict YAN to the nucleus in vivo. (A-E'') Confocal images of germband extended Drosophila embryos double labeled with anti-YAN (A-E,A'-E') and anti-ELAV (A''-E''). (A'-E') Higher magnification views of regions boxed in A-E with normal or failed YAN downregulation highlighted by bracket. ELAV GAL4 was used to drive expression of (A,A',A'') UAS YAN^ACT; (B,B',B'') UAS YAN^WT; (C,C',C'') UAS YAN^{Int NLS}; (D,D',D'') UAS YAN^{2x Int NLS}; (E,E',E'') UAS YAN^{Mut NLS}. YAN^WT is downregulated normally in the ventral nerve cord (B,B'), allowing neuronal differentiation to proceed (B''). As with YAN^ACT (A,A',A''), insertion of an NLS restricts YAN to the nucleus (C,C',D,D'), thereby blocking CNS development (C'',D'').