Distribution of neuropeptide Y-GFP vesicles along the axons and at the neuromuscular junctions (NMJ) of <i>Drosophila</i> larvae.

<p>Vesicular neuropeptide-Y-GFP (NPY-GFP) expression was visualized by anti-GFP immunostaining (in green) in larval motoneurons expressing hHtt^548aa detected by anti-hHtt (Hu-4C8) (in red), in different genotypes: A- <i>OK6</i>-Gal4/+; UAS-NPY-GFP/UAS-0Q-hHtt^548aa (hHtt). B- <i>OK6</i>-Gal4/UAS-128Q-hHtt^548aa; UAS-NPY-GFP;/UAS-LacZ (polyQ-hHtt; LacZ). C- <i>OK6</i>-Gal4/UAS-128Q-hHtt^548aa; UAS-NPY-GFP/UAS-P42 (polyQ-hHtt; P42). Merged images are shown. D- Muscle 4 NMJs are shown in the different genetic backgrounds: 1- <i>OK6</i>-Gal4/+; UAS-NPY-GFP/UAS-0Q-hHtt^548aa (hHtt). 2- <i>OK6</i>-Gal4/UAS-128Q-hHtt^548aa; UAS-NPY-GFP;/UAS-LacZ (polyQ-hHtt; LacZ). 3- <i>OK6</i>-Gal4/UAS-128Q-hHtt^548aa; UAS-NPY-GFP/UAS-P42 (polyQ-hHtt; P42). When expressing wild-type hHtt, NPY-GFP and 0Q-hHtt^548aa are uniformly distributed along the axons and 0Q-hHtt^548aa did not reach the NMJ boutons whereas NPY-GFP did (arrows in D1). In contrast to this control, 128Q-hHtt^548aa is found in large aggregates (see arrows in B and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0068775#pone.0068775.s007" target="_blank">Figure S7</a>) and NPY-GFP vesicles form clogs along the axons, and 128Q-hHtt^548aa accumulates at the NMJ boutons (arrows in D2). Note that the presence of P42 restores the normal distribution of NPY-GFP and 128Q-hHtt^548aa both along the axons and at the NMJ boutons (arrows in D3).