Homozygous TauEGFP knock-in mice 21 were purchased from the Jackson Laboratories and bred with C57Bl6 mice (Taconic) to generate TauEGFP heterozygous embryos. MEFs were isolated from E14.5 embryos using a dissection microscope (Leica). Tail tips were sliced into small pieces, trypsinized and plated to derive fibroblast cultures. All fibroblasts were expanded for three passages before being used for experiments. Complementary DNAs for candidate genes were cloned into doxycycline-inducible lentiviral vectors, as described previously35. MEFs were infected overnight and cultured in MEF media with doxycycline for 48 hours before being transferred into N3 media with doxycycline.
