Differential brain expression of 3R and 4R Tau isoforms in aging wild‐type and young genetically engineered PSEN1 mutant marmosets

The common marmoset (Callithrix jacchus) has emerged as an important model for studying Alzheimer’s disease (AD). Several previous publications reported the natural and spontaneous accumulation of Aβ aggregates in aging marmosets. However, the presentation of tau in aging marmosets has been understudied. A recent report investigated the expression of different tau isoforms and concluded that only 4R tau is expressed throughout adulthood (Sharma et al., J. Biol. Chem. 2019). Here, we investigated the presence of amyloid and tau aggregates in aged wild‐type marmosets and in young adult individuals genetically engineered with knock‐in (KI) point mutations in the PSEN1 gene that cause early‐onset AD.