A 1.5kb Psn promoter regulatory sequence (PEPC - Psn endogenous promoter cassette) drives expression of the longer isoform of Psn, mutated to carry an amino acid substitution that is equivalent to a E280A mutation in the orthologous human PSEN1 gene, a variant associated with familial Alzheimer disease.
The vast majority of PsnE280A.PEPC.L flies exhibit neurogenic defects, ranging from mild to severe, manifesting as a rough eye phenotype, wing notching, and abnormal thoracic bristle patterning. A small proportion of these flies die at the prepupal stage.