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 M146L mutation in the orthologous human PSEN1 gene, a variant associated with familial Alzheimer disease.
PsnM146L.PEPC.L flies generally exhibit a weak neurogenic phenotype, with mild eye phenotypes including supernumerary photoreceptor cells, wing notching, and mild abnormal thoracic bristle patterning.
Based on statistical analysis of the age of onset and the severity of the phenotype, the following Psn alleles can be ranked in the following order, from strongest to weakest: PsnL166P.PEPC.L = PsnL173W.PEPC.L = PsnP436Q.PEPC.L = PsnV272A.PEPC.L = PsnL235P.PEPC.L > PsnM146L.PEPC.L = PsnM139V.PEPC.L = PsnH163R.PEPC.L = PsnE280A.PEPC.L = PsnA246E.PEPC.L = PsnG206A.PEPC.L > PsnA79V.PEPC.L = PsnF175S.PEPC.L = PsnE318G.PEPC.L.