UAS regulatory sequences drive expression of a fusion protein composed of the Aβ1-42 peptide tagged with CRY2(PHR) and mCherry. A CRY2(PHR)-mCherry fusion protein has previously been shown to oligomerize in response to blue light of 488nm (PMID:23377377). In this transgene, the presence of the CRY2(PHR)-mCherry part of the fusion protein allows irreversible light-induced clustering of the Aβ1-42 peptide.