In Vitro and In Vivo Biochemical Analysis of F20E and I31E/E22G Aβ<sub>42</sub>

<div><p>(A) F20E Aβ<sub>42</sub> (blue squares) aggregates more slowly than WT Aβ<sub>42</sub> (red circles), and both were found to have formed well-defined fibrils at the end point of this assay (<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0050290#pbio-0050290-sg003" target="_blank">Figure S3</a>).</p> <p>(B) Immunohistochemistry shows extensive Aβ<sub>42</sub> deposition (brown staining) in the brain of WT-Aβ<sub>42</sub>--expressing flies at 20 d of age (arrows).</p> <p>(C) In contrast, F20E Aβ<sub>42</sub> flies show no evidence of Aβ<sub>42</sub> deposition at 20 d of age.</p> <p>(D) Both E22G (red circles) and I31E/E22G (blue squares) Aβ<sub>42</sub> aggregate at similar rates as measured by Thioflavin T fluorescence.</p> <p>(E) Aβ<sub>42</sub> immunohistochemistry shows deposition throughout the cortex in the brain of E22G-Aβ<sub>42</sub>-expressing flies at 8 d of age (arrows). This deposition is also associated with the appearance of vacuoles (asterisks).</p> <p>(F) Flies expressing I31E/E22G Aβ<sub>42</sub> show extensive deposition of Aβ<sub>42</sub> throughout their cortex (arrows). In contrast to (E), no evidence of neurodegeneration (vacuolation) is seen.</p></div>