Fig 1.

Gross phenotype of Notch-severe and Notch-mild PS1^−/− mice. (a) Notch-severe (Left) and Notch-mild (Right) B6 × 129 F₂ PS1^−/− mice at 5 weeks of age. Identical to previously reported 129 PS1^−/− animals, the Notch-severe mice were significantly smaller than their Notch-mild or wild-type sibs and presented a grossly deformed vertebral column. The represented Notch-severe animal also manifested back-end paralysis commonly observed in this group. (b and d) Ventral and lateral x-rays, respectively, of a 6-week-old Notch-severe mouse alongside its Notch-mild sib (c and e).