Fig. 1
Generation of TDP-∆C knock-in mouse. a Schematic diagrams of the murine Tardbp gene locus, the gene targeting vector for TDP-∆C knock-in, and the resulting TDP-∆C allele after homologous recombination. A region encoding the C-terminal domain of murine TDP-43 (a.a. 274–414) in Tardbp exon 6 was replaced with a 3 × FLAG tag coding sequence. A neomycin resistance gene (Neor) flanked by FRT sequences inserted into the intron 5 and a diphtheria toxin (DT) cassette inserted downstream of intron 6 were used for positive and negative selection, respectively. 3′-UTR, which is crucial for autoregulation of TDP-43 mRNA, remained intact. b Representative image for genotyping of wild-type (WT) and heterogeneous TDP-∆C knock-in (∆C) mice. Specific primers used for PCR are indicated by arrows in (a). c mRNA levels of TDP-43 and TDP-∆C in the spinal cord (SC) of WT and ∆C mice. Quantitative reverse transcription PCR (RT-PCR) was performed with “WT specific” primers, recognizing only endogenous TDP-43 (TDP-WT) cDNA and “total” primers, recognizing both TDP-WT and TDP-∆C cDNAs. Relative mean of TDP-43 mRNA levels normalized to the WT control are plotted with standard deviation (SD). The level of TDP-WT mRNA did not differ between WT and ∆C mice, therefore, the expression level of TDP-∆C mRNA was almost the same as the endogenous TDP-43 mRNA