Motor deficits and neurodegeneration in the young adult FBXO41−/− mouse. A, Weight curve of FBXO41+/+ and FBXO41−/− mice over a period of 60 d. Four mice of each genotype were included in the analysis (two-way ANOVA, ***p < 0.001, **p < 0.01, mean + SEM). B, P30 littermates were tested for hindlimb clasping. Four mice of each genotype were included in the analysis (Student's t test, **p < 0.01, mean + SEM); 0 = normal phenotype, 3 = worst manifestation of phenotype. C, P30 littermates were subjected to gait analysis. Four mice of each genotype were included in the analysis (Student's t test, **p < 0.01, mean + SEM); 0 = normal phenotype, 3 = worst manifestation of phenotype. D, P30 littermates were subjected to the ledge test. Four mice of each genotype were included in the analysis (Student's t test, *p < 0.05, mean + SEM); 0 = normal phenotype, 3 = worst manifestation of phenotype. E, Immunohistochemistry of paraffin sections from P16 FBXO41+/+ and FBXO41−/− cerebella using a TUNEL detection kit. Red arrows indicate clusters of apoptotic cells and black arrows indicate individual apoptotic cells. Scale bars, 500 μm (panel 1), 100 μm (inset A) and 20 μm (inset B). F–H, Quantification of TUNEL+ cells. Three independent FBXO41+/+ and FBXO41−/− cerebella (F), cortices (G), and hippocampi (H) were included in the analyses (Student's t test, **p < 0.01, *p < 0.05, mean + SEM). I, Cultured cerebellar granule neurons were transfected at DIV2 with control vector, FBXO41 RNAi#5 (functional), or FBXO41 RNAi#8 (nonfunctional) plasmid together with the β-Gal reporter plasmid. Neurons were subjected to immunohistochemistry with the cleaved-caspase-3 antibody to mark apoptotic neurons and the DNA dye Hoechst at DIV6, followed by analysis. Scale bar, 50 μm. Arrowheads indicate transfected neurons. Insets show higher magnification. J, Quantification of apoptotic neurons in I. At least 100 neurons were counted per condition per experiment in three independent experiments (ANOVA, ***p < 0.001, mean + SEM). K, Granule neurons transfected with control plasmids (U6 and pCMVmyc), FBXO41 RNAi #5, and pCMVmyc or FBXO41 RNAi#5 and myc-FBXO41-Res expression plasmid were analyzed as in I. At least 100 neurons were counted per condition per experiment in three independent experiments (ANOVA, ***p < 0.001, mean + SEM).