Figure 1: Selected biochemical and pathological characteristics of transgenic mouse models. (a) Soluble and sarkosyl insoluble fractions of Tau (SInT) were isolated as described [10] and proteins separated by SDS-PAGE on 10% tris-glycine gels. After transfer to nitrocellulose membranes, proteins were immunoblotted with either anti-pS396 (Invitrogen, Carlsbad, CA) or HT7 (Innogenetics, Gent, Belgium). Phosphorylated human Tau (apparent Mr about 64 kDa) is evident in soluble fractions from forebrain and brainstem of all three genotypes. SInT is evident in forebrain and brainstem of terminal TPLH and old biAT mice (age 15 months) but not in the brainstem of old biGT mice (15 months). (b) Immunohistochemistry with AT100 on free-floating sagittal sections of terminal mice shows tangles and neuropil threads in cortex and brainstem of all genotypes, but significantly less in the brainstem of biGT mice. Tauopathy is minimal or absent in pyramidal neurons of the hippocampus of terminal Tau.P301L transgenic mice.