Overexpression of human tau did not interfere with localization of mouse tau to the nucleus in undifferentiated dividing cells.

<p>IFA revealed a punctate nuclear tau species (arrow) immunoreactive to AT8 (A) but not CP13 (B) in dissociated undifferentiated neurospheres. AT8 immunoreactivity, indicative of pSer²⁰²/Thr²⁰⁵ tau, was seen in the nucleus of all genotypes that expressed mouse tau, but was absent in cultures derived from <i>Mapt^0/0</i> or in differentiated cells providing evidenced that it was of mouse origin and corresponded to actively dividing cells but not mature cell types.