Figure 2.
Global transport rates are not significantly affected by tau deletion in mice. At 7 d, 14 d, or 5 h after intravitreal injection of 35S-methionine into wild-type (A, C, E) and tau-null (B, D, F) mice, the optic pathways cut into 1 mm segments were fractionated into cytoskeletal and soluble fractions, which were subjected to 5–15% SDS-PAGE gels, transferred to nitrocellulose, and visualized by autoradiography. Redistributions of slowly transported neurofilament proteins and fast transported snap25 and p135 along axons over time were quantified by densitometric scanning of autoradiographs. Graphs showing relative radioactivity of the labeled protein (vertical axis) plotted against distance from the eye displayed by optic segment number (horizontal axis) indicate that slow transport rate of neurofilament proteins (G–L) and fast transport rates of p135 and snap25 (M, N) are not significantly affected by tau deletion. Eighteen mice (9 tau-null and 9 wild-type controls) were studied to generate the data, and representative images are shown. Wild-type and tau-null mice are represented by squares and diamonds, respectively. ko, Knock-out; wt, wild type.