Htt103Q-mCherry and α-syn-EGFP co-localize and co-aggregate when expressed in dopaminergic neurons. (A) Co-localization of Htt103Q-mCherry and α-syn-EGFP aggregates in cell bodies of dopaminergic neurons (arrows). (B) Co-localization of Htt103Q-mCherry and α-syn-EGFP aggregates in neurites of dopaminergic neurons (arrows). (C) Wild-type Htt (Htt25Q-mCherry) does not form aggregates with α-syn-EGFP. (D and E) The expression of α-syn-EGFP alone or Htt25Q-mCherry does not induce the formation of aggregates. The images in A–E show dopaminergic neurons in the paired posterior lateral 1 (PPL1) cluster marked by an anti-TH antibody (against tyrosine hydroxylase). Genotypes: (A, B) TH-GAL4, UAS-α-syn-EGFP/ UAS-Htt103Q-mCherry, (C) TH-GAL4, UAS-α-syn-EGFP/UAS-Htt25Q-mCherry, (D) TH-GAL4, UAS-α-syn-EGFP and (E) TH-GAL4, UAS-Htt25Q-mCherry. Scale bars represent 10 µm.