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 M139V mutation in the orthologous human PSEN1 gene, a variant associated with familial Alzheimer disease.
PsnM139V.PEPC.L flies exhibit a variety of phenotypes, including decreased viability at late prepupal, pupal, and pharate adult stages. In addition, they exhibit a variety of neurogenic phenotypes, including a roughened eye phenotype with supernumerary photoreceptor cells, wing notching, and abnormal thoracic bristle patterning (including duplicated dorsoscutellar macrochaeta). A large proportion of PsnM139V.PEPC.L flies appear morphologically normal.