Fig. 6. Stabilization and nuclear accumulation of Arm in the Apc1^Q8 Apc2^d40 double mutant. Embryos from Apc1^Q8 Apc2^d40 germ cells that are wild type for both Apc1 and Apc2 zygotically (A), or mutant for Apc1^Q8 Apc2^d40 zygotically (B), stained with anti-Arm antibody. (A,B) Same confocal microscope settings. There is a dramatic increase in the intensity of Arm staining in the combined maternal and zygotic Apc1 Apc2 double mutant embryos. (C-H) Embryos from homozygous Apc1^Q8 Apc2^d40 germ cells that are wild-type for both Apc1 and Apc2 zygotically (C-E), or mutant for Apc1^Q8 Apc2^d40 zygotically (F-H) stained with anti-Arm antibody in green (C,F), or with Hoechst dye to detect nuclei in red (D,G) or both (E,H). Staining of the amnioserosa (arrows in C,F) of a stage 9 mutant embryo reveals a nuclear accumulation of Arm that persists throughout embryogenesis only in the Apc1^Q8 Apc2^d40 maternal/zygotic double mutant.