Fig. 5

APPswe does not rescue APPb morphant phenotype. (A) Quantification of embryos showing rescue from the short, curly tail phenotype. Whereas approximately 25% of embryos injected with APPb-MO alone appeared normal (blue bars), co-injection with wild-type APP₆₉₅ mRNA (purple bars) showed over 50% embryos to be normal. There was a concomitant decrease in the number of embryos showing the severe phenotype. However, when injected with the same amount of mRNA encoding APPswe, there was no increase in embryos with normal phenotype, nor was there any decrease in embryos showing the severe phenotype (yellow bars). p > 0.05 by ANOVA. Error bars are ± S.E.M. ∗∗ p < 0.0044 between APPb-MO-injected embryos and those co-injected with APP₆₉₅ mRNA. (B, C) APPswe mRNA does not rescue the defective convergent-extension phenotype. Embryos were fixed at 12 hpf and labeled with papc RNA probe (B) or fixed at 14 hpf and labeled with tpma RNA probe (C). In situ hybridization with papc at the 4–6-somite stage reveals wider somites in APPb-MO-injected embryos (2), which appear normal in embryos co-injected with APP₆₉₅ mRNA (3) but not with APPswe mRNA (4). Similarly, in situ hybridization with tpma at the 6–8 somite stage show wider myotomal precursors and midline in APPb-MO-injected embryos (2) compared to uninjected embryos (1). Co-injection with APP₆₉₅ mRNA (3) but not APPswe (4) reverses the increased width of the myotomal precursors and midline to near the width in uninjected embryos.