Phenotypes of outbred homozygote FUS/TLS KO mice. (a) PCR genotyping of TLS KO mice. (b) Photograph of TLS+/+ and TLS-/- mice. (c) Body weight changes of TLS-/- mice. (d) Western blot analysis of TLS protein expression in the striatum of TLS+/+, TLS+/-, and TLS-/- mice at 8 weeks. Asterisk indicates non-specific cross reactivity of anti-TAF15-M antibody. (e) TLS-M immunoreactivity in the brain sections from TLS+/+ and TLS-/- mice at 8 weeks. Scale bar: 500 μm. (f) qPCR analysis of FUS/TLS mRNA expression in KO mice. The amplicon was located in the 3’UTR (n = 3). (g, h) Spinal cord sections of 91-week old WT or KO mouse stained with anti-Chat. Scale bar: 10 μm. (i, j) Skeletal muscle sections of 91-week old WT or KO mouse stained with HE. Scale bar: 50 μm. (k) Analysis of tremor-like movements of WT or KO mice at 56 weeks. Amplitude at each frequency were determined by fast Fourier transformation of records from an accelerometer (n = 13 for WT, n = 15 for KO). (l) Motion power percentage (MPP; see Additional file 1: Supplemental Materials and Methods) of the range of 10-20 Hz were not elevated in FUS/TLS KO mice compared to WT mice (n = 13 for WT, n = 15 for KO). P = 0.32 by a two-tailed unpaired t-test. Error bars represent SEM.