Fig. 1.

Loss of Htt-mediated age-dependent death in mice. Control is heterozygous floxed Htt/CAG-CreER mice injected with tamoxifen, and KO is homozygous floxed Htt/CAG-CreER mice injected with tamoxifen. (A) Diagram depicting inactivation of the Htt gene in adult mouse expressing CreER. The mice were intraperitoneally (i.p.) injected with tamoxifen (TAM) 20 mg/mL for 5 continuous days. Mice were examined for 7–11 mo after tamoxifen injection. (B) Western blots showing relative Htt protein levels in the brain of ubiquitous KO and control mice at 2, 4, and 8 mo of age. Ctx, cortex; cere, cerebellum; bs, brainstem; str, striatum; oth, other brain regions. (C) Survival rate of ubiquitous KO mouse and control mice when they were injected with tamoxifen at 2, 4, and 8 mo of age. (D and E) The rotarod performance (D) and body weight (E) of ubiquitous KO mice whose Htt was depleted at 4 or 8 mo of age, the mice were then studied for 10–11 mo after tamoxifen injection. Control is age-matched heterozygous KO mice.