A full-length human TAR DNA binding protein (TARDBP or TDP-43) cDNA sequence was modified to have both an N-terminal myc tag and the glutamine to lysine substitution at amino acid 331 associated with familial ALS (huTDP-43*Q331K). This huTDP-43*Q331K cDNA sequence was inserted between exon 2 and exon 3 of mouse prion protein (Prnp) gene. The resulting Prnp-TDP-43*Q331K transgene was flanked with loxP sites. Founder line 109 was identified with approximately the same total TDP-43 (slightly less huTDP-43*Q331K) expression levels in spinal cord as compared to endogenous TDP-43 in non-transgenic mice.