Mapt Xenograft-Applicable mouse models

Mapt, the mouse ortholog of human MAPT, encodes tau, a natively unfolded microtubule-associated protein whose carboxy-terminal repeat domain binds along the microtubule lattice to promote assembly and regulate axonal transport, while its projection domain and extensive phosphorylation by GSK3 beta, CDK5, and MARK kinases control detachment and aggregation propensity. A decisive species difference drives model design: adult mouse brain expresses almost exclusively four-repeat tau, whereas human brain expresses balanced three-repeat and four-repeat isoforms generated by exon 10 splicing, so intronic and exonic FTDP-17 mutations that shift isoform ratio cannot be modeled on the mouse locus and require humanized MAPT knockin alleles carrying the full genomic region. Coding mutations such as P301S and P301L instead drive filament formation and are commonly modeled by knockin or transgene. Nulls are viable with mild phenotypes because Map1b and Map2 compensate, so deletion answers requirement while humanized or aggregation-prone knockins answer tauopathy mechanism and antibody or antisense oligonucleotide response.

Work with your strain choice to align human tumor models with the immune profile you need.